DFlash Mini Lab
Canonical LFM2.5 CPU evidence
Normal + fourteen speculative methods

LFM2.5
All-14 Study

One target, one CPU protocol, exact greedy verification. V13 minimizes V10 routing overhead; V14 compresses Parareal into a scalar fine-gap estimator.

1.085×best speedup
DFlash7-ACTfastest speculative method
✓ All 15 paths exactnormal + 14 methods
5.436normal tok/s
5.898best tok/s
14speculative methods
354.5Mtarget parameters
2,048draft candidates
Measured performance

Speedup versus normal decoding

Median tokens/s from the same exactness-gated LFM2.5 run.

V13 · optimize V10

MinOp: keep the policy, remove the plumbing

Top-2 is selected inside the Torch drafter; only B×2 IDs/scores cross to NumPy and at most one slot receives the V10 two-way decision.

0.969×V13 speedup
2.16 msselection
26.7guidance

V10 reference: 0.951×, 4.70 ms selection.

V14 · simplify Parareal

One scalar F estimator, one residual update

Instead of correcting the complete top-k field twice, V14 estimates the target's signed top1-top2 gap with intercept + coarse gap + block position.

0.987×V14 speedup
62.5%guidance reduction vs V12
2.48 msselection

Holdout fine-gap MAE 7.151; sign accuracy 69.4% vs coarse 69.4%.

Exactness-gated evidence

Complete benchmark table

Methodtok/svs normalaccepttarget callstok/callselectionguidanceexact
08DFlash7-ACTAdaptive speculation horizon5.8981.085×20.1%19.331.2482.52 ms0.0✓
09V9 DSpark-LiteMarkov correction + survival gate5.7391.056×19.6%19.501.2386.80 ms624.0✓
00Normal autoregressiveTarget-only greedy baseline5.4361.000×0.0%24.001.0000.00 ms0.0✓
11V11 Boltzmann-Gated MOBSUncertainty-gated sparse MOBS5.3750.989×7.4%19.171.2595.83 ms135.3✓
12V12 PARAREALParallel linear residual correction5.3670.987×7.4%19.171.25915.78 ms1226.7✓
14V14 Simple PARAREALScalar fine-gap estimator5.3650.987×7.4%19.171.2592.48 ms460.0✓
01DFlashParallel block argmax5.3490.984×7.4%19.171.2590.39 ms0.0✓
04DFlash4-JUMP-MOBSSparse future anchors5.3270.980×6.5%19.671.22313.08 ms944.0✓
05DFlash5-FUSED-JUMPFused sparse guidance5.3270.980×7.1%19.331.24813.15 ms928.0✓
03DFlash3-MOBSMiddle-out bidirectional selection5.2950.974×7.1%19.331.2487.56 ms773.3✓
06DFlash6-BoltzmannDeterministic Boltzmann exploration5.2780.971×7.9%19.001.2787.73 ms608.0✓
13V13 MinOpFused top-2 V10 fast path5.2700.969×7.9%19.001.2782.16 ms26.7✓
02DFlash2Top-k dynamic-programming path5.2390.964×7.1%19.331.2488.19 ms3866.7✓
07DFlash6-BMOBSBoltzmann anchor + MOBS5.1720.951×6.5%19.671.22410.49 ms705.3✓
10V10 Advanced BoltzmannSparse uncertainty routing5.1680.951×7.7%19.171.2694.70 ms37.7✓
Method explorer

Mechanism simulation

Illustrative mechanism animation; numerical values above are measured.

Complexity:

Protocol

Matched evidence

Target: LiquidAI/LFM2.5-350M-Base

6 held-out prompts × 24 tokens × 3 repeats · 2 CPU threads · float32.

Artifacts

Reproducible outputs

V13 reuses the V10 calibration settings. V14's three coefficients are fit only on training trajectories; benchmark prompts remain held out.

benchmark.json

DFlash3–DFlash14 are experimental DFlash Mini Lab variants, not upstream official DFlash releases. Speed claims apply only to the matched LFM2.5 benchmark shown here.