diff --git a/.kiro/specs/scheduler-sim-discrete-clock/tasks.md b/.kiro/specs/scheduler-sim-discrete-clock/tasks.md
index bc25f081..f61cdc25 100644
--- a/.kiro/specs/scheduler-sim-discrete-clock/tasks.md
+++ b/.kiro/specs/scheduler-sim-discrete-clock/tasks.md
@@ -35,8 +35,8 @@ Test-first throughout (red → green → refactor). Every sub-task leaves the bu
   - _Boundary: main, CliCompat_
   - _Depends: 1.1, 2.1_ (shares the new test file with 2.1, and its output assertions need the pinned clock)
 
-- [ ] 3. Integration: remove the simulator speed fields
-- [ ] 3.1 Remove the simulator speed argument and shadow copy, and update every test that set them
+- [x] 3. Integration: remove the simulator speed fields
+- [x] 3.1 Remove the simulator speed argument and shadow copy, and update every test that set them
   - Remove the simulator's speed argument and its shadow copy, and in the same change update every test that assigns or asserts them: the 22 tests that only assign a speed, the startup test (keep its core frozen-setting assertions, drop the shadow-copy ones), the REPL parameter test's remaining assignments, and the non-zero speed assignments that 2.1 added to the new discrete-clock tests to prove RED (those tests keep asserting the pinned clock) (design.md, Modified Files and the build-order constraint).
   - Rename the three core clock tests that describe simulation speed modes as formula tests, including their test registrations and the file header; update the stale speed comments in the scheduler test build file, in the step-verbosity REPL test (which describe the removed speed argument), and in the command-line flag-meaning comments that describe the simulator speed argument, the simulator header's comments, and the core header's documentation of the speed setting (1/1 in normal mode, 0/1 in simulation mode).
   - Done when a search of the scheduler sources and tests finds no simulator speed argument or shadow copy, only the core speed setting, and the full scheduler suite passes.
@@ -69,3 +69,4 @@ Test-first throughout (red → green → refactor). Every sub-task leaves the bu
 ## Implementation Notes
 - Build dir: `bash src/tools/xce-build.sh scheduler asan xce.build.discrete` builds into `src/xce.build.discrete`; iterate with `meson test -C src/xce.build.discrete --suite scheduler` and grep its testlog for `:FAIL`.
 - 2.1 added `args->sim_speed = DISCRETE_CLOCK_RED_SPEED` (and that define) to `test_sim_discrete_clock.c` to prove RED; 3.1 removes both. Its fixture writer leaves mkdtemp dirs under `/tmp` (as `test_sim_record_output.c` does).
+- `test_clock.c` (~40, ~435) quotes scheduler-core AC 12 "fast mode" wording in its session-timing tests; reword it together with 4.2.
diff --git a/src/scheduler/include/core.h b/src/scheduler/include/core.h
index 69b2a166..fdda7a83 100644
--- a/src/scheduler/include/core.h
+++ b/src/scheduler/include/core.h
@@ -295,6 +295,12 @@ struct xce_sched_core_s {
      * after xce_sched_core_init()); the simulation driver does so via
      * sim.c's sim_set_virtual_clock(). Only bare-core test fixtures that
      * never call either keep the neutral (0,0,1,1) default.
+     *
+     * speed_num/speed_den are not a user-selectable speed: they hold 1/1 in
+     * normal mode (the clock tracks wall-clock time) and 0/1 in simulation
+     * mode (scheduler-sim-discrete-clock: the simulator clock is frozen and
+     * moves only when the replay loop sets virtual_clock_base to a recorded
+     * timestamp).
      */
     _Atomic uint64_t virtual_clock_base;
     _Atomic uint64_t real_clock_base;
diff --git a/src/scheduler/include/sim.h b/src/scheduler/include/sim.h
index 0887e1bb..5f34faa5 100644
--- a/src/scheduler/include/sim.h
+++ b/src/scheduler/include/sim.h
@@ -41,13 +41,6 @@
  *   FILE  *record_file;                 -- optional --sim-output stream
  *                                          (task 11.5 writes to it; this
  *                                          task only opens it)
- *   uint64_t sim_speed_num/sim_speed_den -- the SAME two numbers this task
- *                                          also stamps onto
- *                                          `core.speed_num`/`core.speed_den`
- *                                          (kept here too per design.md's
- *                                          literal struct, e.g. for the
- *                                          REPL/diagnostics to read without
- *                                          reaching into `core`)
  *   bool  verify;                       -- --sim-verify (task 11.4 acts on
  *                                          it; this task only stores it)
  *   bool  interactive;                  -- --interactive/-i (task 12 acts on
@@ -57,14 +50,12 @@
  * struct sketch (scheduler-core spec, task 11.5, Req 5 AC 19) -- added, not
  * merely implied, because writing a `--sim-output` file's initial
  * SnapshotEntry needs the EXACT timestamp Step 2's snapshot scan
- * (sim_locate_and_load_snapshot(), sim.c) chose, and re-deriving it via
- * xce_core_now(&sim->core) from inside sim_loop.c's event loop is NOT
- * equivalent for any --sim-speed other than frozen (0): the virtual clock
- * keeps advancing with real wall-clock time between
- * sched_sim_driver_start() returning and sim_loop.c's first opportunity to
- * write the output header/snapshot, so a re-derived value would drift from
- * "the same SnapshotEntry that was loaded" (AC 19's own wording -- same ts,
- * not merely a same-shaped one taken moments later).
+ * (sim_locate_and_load_snapshot(), sim.c) chose. The simulator clock moves
+ * only at recorded timestamps (the replay loop stamps each event's own
+ * timestamp onto it), so by the time sim_loop.c writes the output
+ * header/snapshot xce_core_now(&sim->core) may already have moved to a later
+ * recorded value; storing the chosen timestamp keeps the output's initial
+ * entry "the same SnapshotEntry that was loaded" (AC 19's own wording).
  *
  * `repl_state` below is a SECOND field beyond design.md's literal sketch
  * (scheduler-core spec, task 12.1, Req 5 AC 22) -- the interactive REPL's
@@ -87,8 +78,6 @@ typedef struct {
     FILE*                   replay_file;
     FILE*                   alt_events_file;
     FILE*                   record_file;
-    uint64_t                sim_speed_num;
-    uint64_t                sim_speed_den;
     bool                    verify;
     bool                    interactive;
     uint64_t                snapshot_ts;
@@ -134,8 +123,10 @@ typedef struct {
  * 13's "The scheduler shall support simulation mode activated by --sim FILE
  * and --sim-start-ts TIMESTAMP", plus this task's own "Add the simulation-
  * mode CLI flags (replay file path, start timestamp, speed, verify,
- * alt-events file, output file, interactive)" bullet -- all seven listed
- * there are fields below). Populated by main.c's argp parsing, passed by
+ * alt-events file, output file, interactive)" bullet -- every flag listed
+ * there except speed is a field below; --sim-speed is a deprecated no-op
+ * whose value main.c only logs, since the simulator clock moves only at
+ * recorded timestamps). Populated by main.c's argp parsing, passed by
  * const pointer into sched_sim_driver_start()/sched_sim_driver_run().
  *
  * Deliberately a plain, self-contained struct -- only primitive/string
@@ -152,9 +143,6 @@ typedef struct {
     const char* replay_path;  /* --sim FILE (required) */
     uint64_t    sim_start_ts; /* --sim-start-ts TIMESTAMP (optional;
                                * default SCHED_SIM_START_TS_LATEST) */
-    uint64_t sim_speed;       /* --sim-speed N: 0=as-fast-as-possible,
-                               * 1=real-time, N>1=N x real-time
-                               * (optional; default 1) */
     bool verify;              /* --sim-verify (task 11.4) */
     const char*
         alt_events_path;      /* --sim-alt-events FILE (optional, task 11.5) */
@@ -218,9 +206,10 @@ typedef struct {
  * not from core.c -- core.c's "zero wall-clock calls" isolation boundary,
  * test_core_isolation.c, is scoped to core.c specifically, not to driver-
  * level code that legitimately seeds the core's clock anchors), and
- * `sim->core.speed_num`/`speed_den` to `args->sim_speed`/1. From this point,
- * `xce_core_now(&sim->core)` returns virtual time computed from the
- * snapshot's own logical timestamp -- this function's own Observable.
+ * `sim->core.speed_num`/`speed_den` to 0/1 (frozen: the simulator clock
+ * moves only when the replay loop stamps a recorded timestamp onto it, never
+ * with wall-clock time). From this point, `xce_core_now(&sim->core)` returns
+ * the snapshot's own logical timestamp -- this function's own Observable.
  *
  * Known scope boundary: this function does NOT register any picker plugin
  * into `sim->core.plugins` (builtin_fcfs and friends are only registrable
diff --git a/src/scheduler/src/main.c b/src/scheduler/src/main.c
index 317f25b1..ceab9e18 100644
--- a/src/scheduler/src/main.c
+++ b/src/scheduler/src/main.c
@@ -70,9 +70,12 @@ struct arguments {
      * here, same as sim_file/record_dir above -- numeric/bool
      * interpretation happens in main() after argp_parse() returns (see
      * sched_sim_args_t's own field comments, sim.h, for each flag's
-     * meaning/default). */
+     * meaning/default). --sim-speed is the exception: it has no
+     * sched_sim_args_t field (the simulator clock moves only at recorded
+     * timestamps); its raw value is kept only for the deprecation warning. */
     char* sim_start_ts;   /* --sim-start-ts TIMESTAMP */
-    char* sim_speed;      /* --sim-speed N */
+    char* sim_speed;      /* --sim-speed N (deprecated no-op; value only
+                           * logged by sched_cli_warn_deprecated_options) */
     int   sim_verify;     /* --sim-verify */
     char* sim_alt_events; /* --sim-alt-events FILE */
     char* sim_output;     /* --sim-output FILE */
diff --git a/src/scheduler/src/sim.c b/src/scheduler/src/sim.c
index 5daec7e1..4c2bd46a 100644
--- a/src/scheduler/src/sim.c
+++ b/src/scheduler/src/sim.c
@@ -313,10 +313,7 @@ static int sim_locate_and_load_snapshot(xce_sched_sim_driver_t* sim,
  * xce_core_now() returns exactly snapshot_ts, and afterwards exactly the
  * last value sim_advance_virtual_clock() (sim_loop.c) set, however much
  * real time passes. This is the only place simulation mode sets the speed;
- * the --sim-speed value (sched_sim_args_t.sim_speed) is no longer read.
- * The sim_speed_num/sim_speed_den shadow copy is still written (always
- * 0/1) for `info config` and test_sim_startup.c; the shadow copy and
- * sched_sim_args_t.sim_speed are removed in task 3.1.
+ * the simulator has no speed argument (--sim-speed is a deprecated no-op).
  */
 static void sim_set_virtual_clock(xce_sched_sim_driver_t* sim,
                                   uint64_t                snapshot_ts)
@@ -334,9 +331,6 @@ static void sim_set_virtual_clock(xce_sched_sim_driver_t* sim,
                           memory_order_release);
     atomic_store_explicit(&(sim->core.speed_num), 0, memory_order_release);
     atomic_store_explicit(&(sim->core.speed_den), 1, memory_order_release);
-
-    sim->sim_speed_num = 0;
-    sim->sim_speed_den = 1;
 }
 
 /*
diff --git a/src/scheduler/testsuite/meson.build b/src/scheduler/testsuite/meson.build
index 42ed03c8..3cad61b4 100644
--- a/src/scheduler/testsuite/meson.build
+++ b/src/scheduler/testsuite/meson.build
@@ -316,7 +316,8 @@ sched_core_session_test = executable(
 
 # Contract test for clock virtualization and session timing (scheduler-core
 # spec, task 4.5, Req 5 AC 3 / AC 12): xce_core_now()'s two-anchor + speed
-# formula for all four documented modes, xce_core_tlog_format()'s tlog
+# formula (normal 1/1, simulation frozen 0/1, plus formula tests with other
+# ratios), xce_core_tlog_format()'s tlog
 # integration (frozen virtual time shown instead of info->time's real
 # wall-clock read), and session_start/session_duration_ns tracking across a
 # real xce_core_go()/xce_core_end_session() cycle. Same white-box #include
@@ -563,7 +564,7 @@ sched_admin_request_test = executable(
 # be ReplayHeader, first data message must be SnapshotEntry), locating the
 # most recent SnapshotEntry at or before --sim-start-ts, loading it via the
 # real xce_sched_core_load_snapshot(), and setting the virtual clock's
-# anchors from the loaded snapshot's timestamp and requested speed. Same
+# anchors from the loaded snapshot's timestamp, frozen (speed 0/1). Same
 # white-box #include pattern as sched_snapshot_save_load_test (../src/core.c,
 # ../src/core_clock.c, ../src/snapshot.c, ../src/snapshot_wire.c,
 # ../src/snapshot_load.c) PLUS ../src/recording.c (used only to build real
@@ -1175,9 +1176,9 @@ sched_repl_limit_table_test = executable(
 # sections in a fixed order, aligns every command's description to one
 # consistent column position throughout, lists `info config` together with
 # its `info` siblings in the state-inspection section, lists `set units`
-# alongside `set speed`/`set output`/`set verify` in the snapshot-and-
-# parameters section, and enumerates the complete BP_KIND_TABLE event-type
-# set on the `break` line. Same white-box #include pattern as
+# alongside `set output`/`set verify` in the snapshot-and-parameters
+# section (`set speed` was removed, scheduler-sim-discrete-clock), and
+# enumerates the complete BP_KIND_TABLE event-type set on the `break` line. Same white-box #include pattern as
 # sched_repl_resource_table_test above (core.c, core_clock.c, core_events.c,
 # core_session.c, decision.c, plugin.c, plugins/builtin_fcfs.c, recording.c,
 # recording_session.c, sim.c, sim_loop.c, sim_record.c, sim_verify.c,
@@ -1208,8 +1209,9 @@ sched_repl_help_test = executable(
 # standalone .replay file a FRESH sched_sim_driver_start() can load, landing
 # on the exact position the snapshot was taken at (the task's own central
 # Observable, proved end to end via a forked child + a second, real
-# sched_sim_driver_start() call in the parent); `set speed`/`set output`/
-# `set verify` mutate the parameters `info config` reports. Same white-box
+# sched_sim_driver_start() call in the parent); `set output`/`set verify`
+# mutate the parameters `info config` reports, and the removed `set speed`
+# prints a removal message and changes nothing. Same white-box
 # #include pattern as sched_repl_breakpoints_inspection_test above (core.c,
 # core_clock.c, core_events.c, core_session.c, decision.c, plugin.c,
 # plugins/builtin_fcfs.c, recording.c, recording_session.c, sim.c,
diff --git a/src/scheduler/testsuite/test_clock.c b/src/scheduler/testsuite/test_clock.c
index 583b95c2..36c0fcb1 100644
--- a/src/scheduler/testsuite/test_clock.c
+++ b/src/scheduler/testsuite/test_clock.c
@@ -4,16 +4,20 @@
  *
  * Observable under test:
  *   - xce_core_now() implements the two-anchor + speed formula (Req 5 AC 3)
- *     exactly, for all four documented operating modes (normal, discrete
- *     simulation, real-time simulation, fast/slow simulation), given fixed
- *     anchor values -- no sleep-based real-elapsed-time assertions. Where a
- *     mode's own definition makes the output track real wall-clock time
- *     (normal, real-time, fast/slow), the test brackets the result between
- *     two back-to-back CLOCK_MONOTONIC reads taken immediately before/after
+ *     exactly, given fixed anchor values -- no sleep-based
+ *     real-elapsed-time assertions. The product uses two settings of the
+ *     speed atoms: 1/1 in normal mode and 0/1 (frozen) in simulation mode
+ *     (scheduler-sim-discrete-clock: the simulator has no speed modes).
+ *     Three further tests exercise the formula itself with an arbitrary
+ *     virtual anchor and with ratios 1/1, N/1 and 1/N; they test the
+ *     arithmetic, not any product mode. Where the ratio is non-zero the
+ *     output tracks real wall-clock time, so the test brackets the result
+ *     between two back-to-back CLOCK_MONOTONIC reads taken immediately
+ *     before/after
  *     the call -- deterministic (time is monotonic, so the bracket always
  *     holds) and fast (nanoseconds of real work between the two reads), NOT
  *     the sleep-then-check-approximate-elapsed pattern this task forbids.
- *     Discrete-simulation (frozen, speed=0/1) collapses the bracket to an
+ *     Simulation mode (frozen, speed=0/1) collapses the bracket to an
  *     exact equality since elapsed*0/den is always 0 regardless of when the
  *     test runs.
  *   - xce_core_tlog_format() (core_clock.c's registered tlog_format_func)
@@ -161,12 +165,11 @@ static void test_xce_core_now_discrete_simulation_frozen_at_event_ts(void)
 }
 
 static void
-test_xce_core_now_realtime_simulation_tracks_wall_clock_from_anchor(void)
+test_xce_core_now_unit_ratio_tracks_wall_clock_from_virtual_anchor(void)
 {
-    /* Simulation real-time (AC 3's table): virtual_clock_base=snapshot ts,
-     * real_clock_base=wall at load, speed=1/1 -- tracks wall clock from the
-     * virtual anchor: result is between [snapshot_ts, snapshot_ts +
-     * (after-before)]. */
+    /* Formula test: an arbitrary virtual_clock_base, real_clock_base=wall
+     * now, speed=1/1 -- the result advances with the wall clock from the
+     * virtual anchor: it lies in [anchor, anchor + (after-before)]. */
     xce_sched_core_t core;
     const uint64_t   SNAPSHOT_TS = 500000000000ULL;
     uint64_t         before, result, after;
@@ -182,10 +185,10 @@ test_xce_core_now_realtime_simulation_tracks_wall_clock_from_anchor(void)
     TEST_ASSERT_TRUE(result <= SNAPSHOT_TS + (after - before));
 }
 
-static void test_xce_core_now_fast_simulation_scales_up_by_speed(void)
+static void test_xce_core_now_ratio_above_one_scales_elapsed_up(void)
 {
-    /* Simulation fast (AC 3's table): speed=N/1 -- runs N times faster than
-     * wall clock. Bracket scaled by N. */
+    /* Formula test: speed=N/1 -- elapsed wall time is multiplied by N.
+     * Bracket scaled by N. */
     xce_sched_core_t core;
     const uint64_t   SNAPSHOT_TS = 1000ULL;
     const uint64_t   N           = 1000ULL;
@@ -202,11 +205,10 @@ static void test_xce_core_now_fast_simulation_scales_up_by_speed(void)
     TEST_ASSERT_TRUE(result <= SNAPSHOT_TS + (after - before) * N);
 }
 
-static void test_xce_core_now_slow_simulation_scales_down_by_speed(void)
+static void test_xce_core_now_ratio_below_one_scales_elapsed_down(void)
 {
-    /* Simulation slow (AC 3's table): speed=1/N -- runs N times slower than
-     * wall clock. Bracket scaled down by N (+1 for integer-division
-     * rounding slack). */
+    /* Formula test: speed=1/N -- elapsed wall time is divided by N.
+     * Bracket scaled down by N (+1 for integer-division rounding slack). */
     xce_sched_core_t core;
     const uint64_t   SNAPSHOT_TS = 1000ULL;
     const uint64_t   N           = 1000ULL;
@@ -494,9 +496,9 @@ int main(void)
     RUN_TEST(test_xce_core_now_normal_mode_matches_wall_clock);
     RUN_TEST(test_xce_core_now_discrete_simulation_frozen_at_event_ts);
     RUN_TEST(
-        test_xce_core_now_realtime_simulation_tracks_wall_clock_from_anchor);
-    RUN_TEST(test_xce_core_now_fast_simulation_scales_up_by_speed);
-    RUN_TEST(test_xce_core_now_slow_simulation_scales_down_by_speed);
+        test_xce_core_now_unit_ratio_tracks_wall_clock_from_virtual_anchor);
+    RUN_TEST(test_xce_core_now_ratio_above_one_scales_elapsed_up);
+    RUN_TEST(test_xce_core_now_ratio_below_one_scales_elapsed_down);
     RUN_TEST(test_xce_sched_core_init_seeds_normal_mode_defaults);
     RUN_TEST(test_xce_core_set_wallclock_anchor_seeds_real_epoch_time);
     RUN_TEST(test_xce_core_set_wallclock_anchor_null_core_is_a_safe_noop);
diff --git a/src/scheduler/testsuite/test_repl_breakpoints_inspection.c b/src/scheduler/testsuite/test_repl_breakpoints_inspection.c
index 4c1404ec..13d891ab 100644
--- a/src/scheduler/testsuite/test_repl_breakpoints_inspection.c
+++ b/src/scheduler/testsuite/test_repl_breakpoints_inspection.c
@@ -2017,7 +2017,6 @@ static void run_group_d_child(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_repl_equivalence.c b/src/scheduler/testsuite/test_repl_equivalence.c
index 8ffcc71d..afa2f7bd 100644
--- a/src/scheduler/testsuite/test_repl_equivalence.c
+++ b/src/scheduler/testsuite/test_repl_equivalence.c
@@ -860,9 +860,6 @@ test_repl_step_continue_to_completion_matches_batch_decision_sequence(void)
     memset(&args_batch, 0, sizeof(args_batch));
     args_batch.replay_path  = fixture_path;
     args_batch.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args_batch.sim_speed    = 0; /* frozen -- deterministic, no wall-clock
-                                  * skew, matching every other equivalence
-                                  * fixture in this directory */
     args_batch.output_path  = batch_out_path;
     args_batch.interactive  = false;
 
@@ -892,7 +889,6 @@ test_repl_step_continue_to_completion_matches_batch_decision_sequence(void)
     memset(&args_repl, 0, sizeof(args_repl));
     args_repl.replay_path  = fixture_path;
     args_repl.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args_repl.sim_speed    = 0;
     args_repl.output_path  = repl_out_path;
     args_repl.interactive  = true;
 
diff --git a/src/scheduler/testsuite/test_repl_event_echo.c b/src/scheduler/testsuite/test_repl_event_echo.c
index 74c3833e..ebc0e4a7 100644
--- a/src/scheduler/testsuite/test_repl_event_echo.c
+++ b/src/scheduler/testsuite/test_repl_event_echo.c
@@ -659,7 +659,6 @@ static void child_run_repl_and_exit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_repl_execution_control.c b/src/scheduler/testsuite/test_repl_execution_control.c
index 3640300a..6004b149 100644
--- a/src/scheduler/testsuite/test_repl_execution_control.c
+++ b/src/scheduler/testsuite/test_repl_execution_control.c
@@ -741,7 +741,6 @@ static void child_prepause_then_quit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
@@ -867,7 +866,6 @@ static void child_continue_then_inspect(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
@@ -962,7 +960,6 @@ static void child_continue_twice_after_complete(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
@@ -1067,7 +1064,6 @@ static void child_step_then_quit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_repl_limit_table.c b/src/scheduler/testsuite/test_repl_limit_table.c
index bb7d38ef..26fae20a 100644
--- a/src/scheduler/testsuite/test_repl_limit_table.c
+++ b/src/scheduler/testsuite/test_repl_limit_table.c
@@ -2759,7 +2759,6 @@ static void det_run_scripted_repl_session(const char* fixture_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = (char*)fixture_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.output_path  = out_path;
     args.interactive  = true;
 
diff --git a/src/scheduler/testsuite/test_repl_prompt_context.c b/src/scheduler/testsuite/test_repl_prompt_context.c
index 3c6a413f..480126ed 100644
--- a/src/scheduler/testsuite/test_repl_prompt_context.c
+++ b/src/scheduler/testsuite/test_repl_prompt_context.c
@@ -638,7 +638,6 @@ static char* run_repl_via_pty(const char* replay_path, const char* script)
         memset(&args, 0, sizeof(args));
         args.replay_path  = replay_path;
         args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-        args.sim_speed    = 0;
         args.interactive  = true;
 
         (void)sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_repl_round_rollup.c b/src/scheduler/testsuite/test_repl_round_rollup.c
index d513f260..9b4d62f5 100644
--- a/src/scheduler/testsuite/test_repl_round_rollup.c
+++ b/src/scheduler/testsuite/test_repl_round_rollup.c
@@ -776,7 +776,6 @@ static void child_run_repl_and_exit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_repl_snapshot_params.c b/src/scheduler/testsuite/test_repl_snapshot_params.c
index e29f9090..d1607845 100644
--- a/src/scheduler/testsuite/test_repl_snapshot_params.c
+++ b/src/scheduler/testsuite/test_repl_snapshot_params.c
@@ -676,7 +676,6 @@ static void child_step_snapshot_quit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen virtual clock -- deterministic ts */
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
@@ -812,7 +811,6 @@ static void child_step_snapshot_noarg_quit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
@@ -1312,8 +1310,6 @@ static void test_info_config_reports_current_parameters(void)
     g_cfg_sim.repl_state = repl_state_ensure(&g_cfg_sim);
     TEST_ASSERT_NOT_NULL(g_cfg_sim.repl_state);
 
-    g_cfg_sim.sim_speed_num             = 3;
-    g_cfg_sim.sim_speed_den             = 1;
     g_cfg_sim.verify                    = true;
     g_cfg_sim.repl_state->event_index   = 7;
     g_cfg_sim.repl_state->session_count = 2;
diff --git a/src/scheduler/testsuite/test_repl_step_verbosity.c b/src/scheduler/testsuite/test_repl_step_verbosity.c
index b68883a9..ecafa8a1 100644
--- a/src/scheduler/testsuite/test_repl_step_verbosity.c
+++ b/src/scheduler/testsuite/test_repl_step_verbosity.c
@@ -27,8 +27,8 @@
  * this file exercises the same real sched_sim_driver_run() end-to-end,
  * forked-child, real-stdout-capture technique. Discrete-simulation
  * determinism note (research.md's own key finding, load-bearing for every
- * test below): `child_run_repl_and_exit()` sets args.sim_speed = 0, which
- * sim_set_virtual_clock() (sim.c) stores as core.speed_num == 0; with
+ * test below): simulation mode always runs the core clock frozen --
+ * sim_set_virtual_clock() (sim.c) stores core.speed_num == 0; with
  * speed_num == 0, xce_core_now()'s (core_clock.c) `elapsed * num / den` term
  * is always exactly zero, so xce_core_now() returns EXACTLY the raw
  * nanosecond `ts` value most recently passed to sim_advance_virtual_clock()
@@ -634,9 +634,10 @@ static char* read_whole_file(const char* path)
 /* child_run_repl_and_exit / run_repl_fixture_and_capture - the same fork/
  * freopen/waitpid/capture shape test_repl_event_echo.c's own pair
  * establishes: run a scripted command sequence to completion against a real
- * sched_sim_driver_run(), capturing real stdout. args.sim_speed = 0 below is
- * this file's own load-bearing determinism note (see header comment) -- it
- * is what makes xce_core_now() return EXACTLY each event's own `ts`. */
+ * sched_sim_driver_run(), capturing real stdout. The simulator's frozen
+ * clock is this file's own load-bearing determinism note (see header
+ * comment) -- it is what makes xce_core_now() return EXACTLY each event's
+ * own `ts`. */
 static void child_run_repl_and_exit(const char* replay_path,
                                     const char* script_path,
                                     const char* capture_path)
@@ -655,7 +656,6 @@ static void child_run_repl_and_exit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_sim_alt_events.c b/src/scheduler/testsuite/test_sim_alt_events.c
index aee8273b..fa55f531 100644
--- a/src/scheduler/testsuite/test_sim_alt_events.c
+++ b/src/scheduler/testsuite/test_sim_alt_events.c
@@ -603,7 +603,6 @@ static char* run_sim_and_capture_stdout(const char* base_path,
     memset(&args, 0, sizeof(args));
     args.replay_path     = base_path;
     args.sim_start_ts    = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed       = 0; /* frozen -- deterministic, no wall-clock wait */
     args.alt_events_path = alt_path;
 
     *out_rc = sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_sim_contention_parity.c b/src/scheduler/testsuite/test_sim_contention_parity.c
index 6c2bdc58..e16b4c92 100644
--- a/src/scheduler/testsuite/test_sim_contention_parity.c
+++ b/src/scheduler/testsuite/test_sim_contention_parity.c
@@ -1461,7 +1461,6 @@ test_contention_parity_matches_real_normal_mode_recording_round_by_round(
     memset(&sim_args, 0, sizeof(sim_args));
     sim_args.replay_path  = sim_r_path;
     sim_args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    sim_args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock skew */
 
     memset(&sim, 0, sizeof(sim));
     g_capturing = 1;
@@ -1812,7 +1811,6 @@ static void run_multiround_contention_fixture(xce_sched_sim_driver_t* sim_out,
     memset(&sim_args, 0, sizeof(sim_args));
     sim_args.replay_path  = r_path;
     sim_args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    sim_args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock skew */
 
     memset(sim_out, 0, sizeof(*sim_out));
     rc = sched_sim_driver_run(sim_out, &sim_args);
diff --git a/src/scheduler/testsuite/test_sim_discrete_clock.c b/src/scheduler/testsuite/test_sim_discrete_clock.c
index 7c72cd71..ddf14ae9 100644
--- a/src/scheduler/testsuite/test_sim_discrete_clock.c
+++ b/src/scheduler/testsuite/test_sim_discrete_clock.c
@@ -13,11 +13,10 @@
  * Testing Strategy: Unit (SimClock) and Integration (replay loop)): in
  * simulation mode the logical clock moves only at the start snapshot, at
  * each recorded event and at each recorded session, is set exactly (never
- * clamped, even backwards), and never drifts with real time. Every clock
- * test passes a non-zero speed through the still-present
- * sched_sim_args_t.sim_speed (DISCRETE_CLOCK_RED_SPEED) to prove the
- * simulator no longer reads it; task 3.1 removes that field and these
- * assignments while keeping the pinned-clock assertions.
+ * clamped, even backwards), and never drifts with real time. (Task 2.1
+ * proved RED by passing a non-zero speed through the simulator's speed
+ * argument; task 3.1 removed that argument, and these tests keep asserting
+ * the pinned clock.)
  *
  * White-box #include of the same simulator TU set test_sim_record_output.c
  * uses, with its link-satisfying stubs and stand-in picker; the stand-in
@@ -465,10 +464,6 @@ static void test_no_warning_when_option_absent(void)
 /* chosen value first, so the recorded start snapshot's ts is exact.       */
 /* ---------------------------------------------------------------------- */
 
-/* Task 2.1 RED: a non-zero speed through the still-present simulator
- * argument. The simulator must ignore it; removed with the field in 3.1. */
-#define DISCRETE_CLOCK_RED_SPEED 7
-
 #define SNAP_TS   1000000000000ULL /* start snapshot, 1000 s */
 #define JOB_A     4101ULL
 #define JOB_B     4102ULL
@@ -622,7 +617,6 @@ static void sim_args_init(sched_sim_args_t* args, const char* replay_path)
     memset(args, 0, sizeof(*args));
     args->replay_path  = replay_path;
     args->sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args->sim_speed    = DISCRETE_CLOCK_RED_SPEED;
 }
 
 /* Runs a batch replay with `sim` as the observed core. */
diff --git a/src/scheduler/testsuite/test_sim_e2e_limit_visibility.c b/src/scheduler/testsuite/test_sim_e2e_limit_visibility.c
index af9429f2..9ac89b47 100644
--- a/src/scheduler/testsuite/test_sim_e2e_limit_visibility.c
+++ b/src/scheduler/testsuite/test_sim_e2e_limit_visibility.c
@@ -580,7 +580,6 @@ test_sim_replay_shows_real_global_and_host_scoped_limit_usage(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
 
     rc = sched_sim_driver_run(&g_sim, &args);
     TEST_ASSERT_EQUAL_INT_MESSAGE(
diff --git a/src/scheduler/testsuite/test_sim_e2e_original_motivation.c b/src/scheduler/testsuite/test_sim_e2e_original_motivation.c
index 24bc8d42..e129f37e 100644
--- a/src/scheduler/testsuite/test_sim_e2e_original_motivation.c
+++ b/src/scheduler/testsuite/test_sim_e2e_original_motivation.c
@@ -1368,7 +1368,6 @@ static void child_replay(const char* replay_path, const char* script_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen -- deterministic */
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_sim_equivalence.c b/src/scheduler/testsuite/test_sim_equivalence.c
index bcdfb0fa..cb88989a 100644
--- a/src/scheduler/testsuite/test_sim_equivalence.c
+++ b/src/scheduler/testsuite/test_sim_equivalence.c
@@ -1016,7 +1016,6 @@ test_normal_mode_recording_and_simulation_replay_produce_identical_decisions(
     memset(&sim_args, 0, sizeof(sim_args));
     sim_args.replay_path  = r_path;
     sim_args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    sim_args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock skew */
     sim_args.output_path  = s_path;
 
     rc = sched_sim_driver_run(&sim, &sim_args);
diff --git a/src/scheduler/testsuite/test_sim_event_loop.c b/src/scheduler/testsuite/test_sim_event_loop.c
index 36e4913b..e6813325 100644
--- a/src/scheduler/testsuite/test_sim_event_loop.c
+++ b/src/scheduler/testsuite/test_sim_event_loop.c
@@ -808,7 +808,6 @@ test_run_processes_multiple_sessions_in_order_and_no_longer_returns_enosys(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen -- deterministic final-clock assertion */
 
     rc = sched_sim_driver_run(&sim, &args);
 
@@ -865,7 +864,6 @@ test_run_deactivates_tlog_virtual_clock_logging_on_completion(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
 
     xce_core_set_active_for_logging((xce_sched_core_t*)0x1); /* bogus sentinel */
 
@@ -983,7 +981,6 @@ static char* run_sim_and_capture_stdout(const char* path, int* out_rc)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock wait */
 
     *out_rc = sched_sim_driver_run(&sim, &args);
 
diff --git a/src/scheduler/testsuite/test_sim_live_allocation.c b/src/scheduler/testsuite/test_sim_live_allocation.c
index 1862cae5..e2d630fd 100644
--- a/src/scheduler/testsuite/test_sim_live_allocation.c
+++ b/src/scheduler/testsuite/test_sim_live_allocation.c
@@ -444,7 +444,6 @@ static char* run_sim_and_capture_stdout(xce_sched_sim_driver_t* sim,
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.verify       = verify;
 
     *out_rc = sched_sim_driver_run(sim, &args);
@@ -580,7 +579,6 @@ test_sim_driver_run_dispatches_a_job_with_available_resources(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
 
     rc = sched_sim_driver_run(&g_sim, &args);
     TEST_ASSERT_EQUAL_INT_MESSAGE(
diff --git a/src/scheduler/testsuite/test_sim_print_decision_gate.c b/src/scheduler/testsuite/test_sim_print_decision_gate.c
index 24f9c5d8..3b9a08f1 100644
--- a/src/scheduler/testsuite/test_sim_print_decision_gate.c
+++ b/src/scheduler/testsuite/test_sim_print_decision_gate.c
@@ -663,7 +663,6 @@ static void child_run_repl_and_exit(const char* replay_path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
     args.interactive  = true;
 
     (void)sched_sim_driver_run(&sim, &args);
@@ -739,7 +738,6 @@ static char* run_sim_and_capture_stdout(const char* replay_path, int* out_rc)
     memset(&args, 0, sizeof(args));
     args.replay_path  = replay_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock wait */
     /* args.interactive left false -- this is the headless/batch path. */
 
     *out_rc = sched_sim_driver_run(&sim, &args);
diff --git a/src/scheduler/testsuite/test_sim_record_output.c b/src/scheduler/testsuite/test_sim_record_output.c
index d74864a9..f8e4bc94 100644
--- a/src/scheduler/testsuite/test_sim_record_output.c
+++ b/src/scheduler/testsuite/test_sim_record_output.c
@@ -593,7 +593,6 @@ static void test_output_file_is_decodable_with_full_stream_symmetry(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = base_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen -- deterministic snapshot_ts */
     args.output_path  = out_path;
 
     rc = sched_sim_driver_run(&sim, &args);
@@ -786,7 +785,6 @@ static void test_output_file_reflects_alt_events_not_base_when_both_set(void)
     memset(&args, 0, sizeof(args));
     args.replay_path     = base_path;
     args.sim_start_ts    = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed       = 0;
     args.alt_events_path = alt_path;
     args.output_path     = out_path;
 
diff --git a/src/scheduler/testsuite/test_sim_resource_contention.c b/src/scheduler/testsuite/test_sim_resource_contention.c
index a20f2314..3ae5bb6b 100644
--- a/src/scheduler/testsuite/test_sim_resource_contention.c
+++ b/src/scheduler/testsuite/test_sim_resource_contention.c
@@ -1062,7 +1062,6 @@ static void test_contention_fixture_is_replayable_via_simulation_driver(void)
     memset(&sim_args, 0, sizeof(sim_args));
     sim_args.replay_path  = r_path;
     sim_args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    sim_args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock skew */
 
     memset(&sim, 0, sizeof(sim));
     rc = sched_sim_driver_run(&sim, &sim_args);
diff --git a/src/scheduler/testsuite/test_sim_round_boundary_reconciliation.c b/src/scheduler/testsuite/test_sim_round_boundary_reconciliation.c
index d345dbb1..f63fcdf9 100644
--- a/src/scheduler/testsuite/test_sim_round_boundary_reconciliation.c
+++ b/src/scheduler/testsuite/test_sim_round_boundary_reconciliation.c
@@ -866,7 +866,6 @@ test_reconciled_job_charges_resinuse_before_live_capacity_check(void)
     memset(&sim_args, 0, sizeof(sim_args));
     sim_args.replay_path  = r_path;
     sim_args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    sim_args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock skew */
 
     memset(&sim, 0, sizeof(sim));
     rc = sched_sim_driver_run(&sim, &sim_args);
diff --git a/src/scheduler/testsuite/test_sim_session_ordering.c b/src/scheduler/testsuite/test_sim_session_ordering.c
index 0051fc90..635d7ab6 100644
--- a/src/scheduler/testsuite/test_sim_session_ordering.c
+++ b/src/scheduler/testsuite/test_sim_session_ordering.c
@@ -901,7 +901,6 @@ test_sim_replay_calls_account_jobs_once_per_round_within_session_window(
     memset(&sim_args, 0, sizeof(sim_args));
     sim_args.replay_path  = r_path;
     sim_args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    sim_args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock skew */
 
     memset(&sim, 0, sizeof(sim));
     rc = sched_sim_driver_run(&sim, &sim_args);
@@ -1010,7 +1009,6 @@ static void test_sim_replay_batch_mode_uses_the_same_round_boundary(void)
     memset(&sim_args, 0, sizeof(sim_args));
     sim_args.replay_path  = r_path;
     sim_args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    sim_args.sim_speed    = 0;
 
     memset(&sim, 0, sizeof(sim));
     TEST_ASSERT_EQUAL_INT(0, sim.interactive); /* batch: default-zero, never set */
diff --git a/src/scheduler/testsuite/test_sim_snapshot_reconcile_gap.c b/src/scheduler/testsuite/test_sim_snapshot_reconcile_gap.c
index 88f88499..c4451791 100644
--- a/src/scheduler/testsuite/test_sim_snapshot_reconcile_gap.c
+++ b/src/scheduler/testsuite/test_sim_snapshot_reconcile_gap.c
@@ -704,7 +704,6 @@ static char* run_sim_and_capture_stdout(const char*             path,
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock wait */
     args.verify       = verify;
 
     *out_rc = sched_sim_driver_run(out_sim, &args);
diff --git a/src/scheduler/testsuite/test_sim_startup.c b/src/scheduler/testsuite/test_sim_startup.c
index c55a38d5..6f011ad4 100644
--- a/src/scheduler/testsuite/test_sim_startup.c
+++ b/src/scheduler/testsuite/test_sim_startup.c
@@ -419,10 +419,6 @@ test_valid_fixture_reaches_ready_state_with_frozen_virtual_clock(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* fast/frozen -- xce_core_now() stays pinned to
-                            * virtual_clock_base regardless of real elapsed
-                            * time, giving this test a deterministic,
-                            * non-flaky assertion. */
 
     rc = sched_sim_driver_start(&sim, &args);
     TEST_ASSERT_EQUAL_INT(0, rc);
@@ -439,8 +435,6 @@ test_valid_fixture_reaches_ready_state_with_frozen_virtual_clock(void)
                                                         memory_order_acquire));
     TEST_ASSERT_EQUAL_UINT64(1ULL, atomic_load_explicit(&(sim.core.speed_den),
                                                         memory_order_acquire));
-    TEST_ASSERT_EQUAL_UINT64(0ULL, sim.sim_speed_num);
-    TEST_ASSERT_EQUAL_UINT64(1ULL, sim.sim_speed_den);
 
     /* "Ready-to-run" -- no session is active, load_snapshot()'s own
      * precondition would otherwise have been violated. */
@@ -481,7 +475,6 @@ static void test_valid_fixture_activates_virtual_clock_for_tlog_logging(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0;
 
     rc = sched_sim_driver_start(&sim, &args);
     TEST_ASSERT_EQUAL_INT(0, rc);
@@ -518,7 +511,6 @@ static void test_missing_initial_snapshot_entry_fails_cleanly(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = header_only_path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 1;
 
     rc = sched_sim_driver_start(&sim, &args);
     TEST_ASSERT_TRUE(rc < 0);
@@ -546,7 +538,6 @@ static void test_first_message_not_replayheader_fails_cleanly(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 1;
 
     rc = sched_sim_driver_start(&sim, &args);
     TEST_ASSERT_TRUE(rc < 0);
@@ -568,7 +559,6 @@ static void test_missing_replay_file_fails_cleanly(void)
     memset(&args, 0, sizeof(args));
     args.replay_path  = "/nonexistent/path/does_not_exist.replay";
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 1;
 
     rc = sched_sim_driver_start(&sim, &args);
     TEST_ASSERT_TRUE(rc < 0);
diff --git a/src/scheduler/testsuite/test_sim_verify.c b/src/scheduler/testsuite/test_sim_verify.c
index 4c949ea3..8d52da61 100644
--- a/src/scheduler/testsuite/test_sim_verify.c
+++ b/src/scheduler/testsuite/test_sim_verify.c
@@ -1517,7 +1517,6 @@ static char* run_sim_and_capture_stdout(const char* path, bool verify,
     memset(&args, 0, sizeof(args));
     args.replay_path  = path;
     args.sim_start_ts = SCHED_SIM_START_TS_LATEST;
-    args.sim_speed    = 0; /* frozen -- deterministic, no wall-clock wait */
     args.verify       = verify;
 
     *out_rc = sched_sim_driver_run(&sim, &args);