diff --git a/tools/analysis/11_cpu_budget.py b/tools/analysis/11_cpu_budget.py
index 008c2ee..7c6910d 100644
--- a/tools/analysis/11_cpu_budget.py
+++ b/tools/analysis/11_cpu_budget.py
@@ -23,9 +23,12 @@ sys.path.insert(0, "tools/encoder")
 import numpy as np
 from dlx import DLX
 
-CPUHZ = 10_000_000
+# Machine clocks, confirmed from MAME 0.277 src/mame/sharp/x68k.cpp:1133/1194/
+# 1200 -- not recalled. x68000 and x68ksupr are BOTH 40_MHz_XTAL/4 = 10 MHz;
+# only the XVI is faster, at 33.33_MHz_XTAL/2. So "has SCSI" and "has a faster
+# CPU" are different sets of machines: the Super has SCSI at 10 MHz.
+CLOCKS = {"stock": 10.0, "super": 10.0, "xvi": 33.33 / 2, "x68030": 25.0}
 FPS = 12
-FRAME = CPUHZ / FPS                       # 833,333 cycles
 
 # cycles per block, measured on the emulated 68000 (synthetic single-mode frames)
 C_V1, C_V4, C_RAW = 299.9, 448.2, 400.4
@@ -35,7 +38,13 @@ C_SKIP_MIXED = 45.0                       # a SKIP block inside a mixed byte
 ap = argparse.ArgumentParser()
 ap.add_argument("container", nargs="?",
                 default="tmp/rc_fr_singe_sasi_rcprofile.dlx")
+ap.add_argument("--machine", default="stock", choices=list(CLOCKS),
+                help="which X68000's clock to budget against (default stock)")
+ap.add_argument("--fps", type=float, default=FPS)
 a = ap.parse_args()
+CPUHZ = CLOCKS[a.machine] * 1e6
+FPS = a.fps
+FRAME = CPUHZ / FPS
 if not os.path.exists(a.container):
     sys.exit(f"missing {a.container}")
 
@@ -58,6 +67,13 @@ pct = 100 * cyc / FRAME
 ns = np.array([100 * (m != 0).mean() for m in modes])
 
 print(f"{a.container}: {d.nframes} frames, {d.nb} blocks/frame")
+print(f"budget: {a.machine} @ {CLOCKS[a.machine]:.2f} MHz, {FPS:g} fps "
+      f"-> {FRAME:,.0f} cycles/frame")
+if a.machine != "stock":
+    print("  (derived: scaled by clock from cycles measured on the 10 MHz core.\n"
+          "   MAME 0.277 marks x68ksupr/x68kxvi/x68030 MACHINE_NOT_WORKING, so\n"
+          "   this is not measured on those machines and ignores any difference\n"
+          "   in memory timing.)")
 print(f"measured block costs: SKIP {C_SKIP_FAST*4:.0f}/4 (clustered) "
       f"{C_SKIP_MIXED:.0f} (mixed)  V1 {C_V1:.0f}  V4 {C_V4:.0f}  RAW {C_RAW:.0f} cycles\n")
 
@@ -67,27 +83,34 @@ print(f"measured block costs: SKIP {C_SKIP_FAST*4:.0f}/4 (clustered) "
 TIMED = "tmp/rc_fr_singe_sasi_rcprofile.dlx"
 TIMED_FRAMES = (("min non-SKIP", 15.4, 31.5), ("median", 48.1, 73.8),
                 ("p90", 82.5, 116.4), ("max non-SKIP", 100.0, 135.8))
-if os.path.abspath(a.container) == os.path.abspath(TIMED):
+if (os.path.abspath(a.container) == os.path.abspath(TIMED)
+        and a.machine == "stock" and a.fps == 12):
     print("model vs the frames actually timed on the 68000:")
     for label, frac, meas in TIMED_FRAMES:
         i = int(np.argmin(abs(ns - frac)))
         print(f"  {label:<14} non-SKIP {ns[i]:5.1f}%   model {pct[i]:6.1f}%   "
               f"measured {meas:5.1f}%   error {pct[i]-meas:+.1f} pt")
 else:
-    print(f"(no 68000 timings for this container -- the model was validated to "
-          f"within\n 1 pt on {TIMED}; run tools/bench/decode.lua to time this one)")
+    print(f"(no 68000 timings for this container/machine -- the model was "
+          f"validated to\n within 1 pt on {TIMED} at stock/12fps;\n"
+          f" run tools/bench/decode.lua to time another container)")
 
-old = 76.6 * ns / 100
-print(f"\nper-frame cost, % of a {FPS}fps frame budget:")
+print(f"\nper-frame cost, % of a {FPS:g}fps frame budget:")
 print(f"  measured-cost model: median {np.median(pct):5.1f}  "
       f"p90 {np.percentile(pct,90):5.1f}  max {pct.max():5.1f}")
-print(f"  FINDINGS 24.5 model: median {np.median(old):5.1f}  "
-      f"p90 {np.percentile(old,90):5.1f}  max {old.max():5.1f}   "
-      f"(optimistic by {np.median(pct)/np.median(old):.2f}x at the median)")
+if a.machine == "stock" and a.fps == 12:
+    # 24.5's 76.6% is a 10 MHz / 12 fps figure; quoting it at another clock or
+    # framerate would be comparing against a model that was never stated there.
+    old = 76.6 * ns / 100
+    print(f"  FINDINGS 24.5 model: median {np.median(old):5.1f}  "
+          f"p90 {np.percentile(old,90):5.1f}  max {old.max():5.1f}   "
+          f"(optimistic by {np.median(pct)/np.median(old):.2f}x at the median)")
 
 miss = pct > 100
-print(f"\nframes that do NOT fit 833,333 cycles: {miss.sum()}/{d.nframes} "
+print(f"\nframes that do NOT fit {FRAME:,.0f} cycles: {miss.sum()}/{d.nframes} "
       f"({100*miss.mean():.0f}%)")
+print(f"  sustainable framerate if EVERY frame must fit: "
+      f"{CPUHZ/cyc.max():.1f} fps; at the mean frame {CPUHZ/cyc.mean():.1f} fps")
 if miss.any():
     print(f"  worst {pct.max():.1f}% -- {(pct.max()-100)/100*1000/FPS:.0f} ms late "
           f"on an {1000/FPS:.0f} ms frame")