Commit Graph

4 Commits

Author SHA1 Message Date
268e40d764 phase 10: add Qwen3-8B benchmark + performance fix
Benchmark infrastructure:
- bench-qwen3 binary: 50 prompts × 20 tokens with KV cache
- bench_compare_qwen3.py: comparison against HF transformers (BF16)

Performance fix:
- Precompute transposed weights at model load time (eliminated per-token
  weight transpose CPU round-trip: was 252 transposes × 32MB each = 8GB/token)
- Result: from "infinite" (>10 min/token) to 144ms/token

Results (50 prompts):
- Prefill top-1: 42/50 (84%), top-5: 50/50 (100%) vs HF transformers
- Greedy sequence: 0/50 exact match (BF16 precision drift over 36 layers)
- Performance: TTFT=138ms, TBT=144ms, 6.9 tok/s (HF: 21ms, 45.6 tok/s)
- All outputs are coherent English/Chinese

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-05-22 10:25:33 +08:00
64084d3489 phase 9: KV cache + autoregressive generation
- KVCache: per-layer, per-head storage with append + reconstruct
- forward_with_cache: prefill (full prompt) + decode (single token) modes
- Fixed data layout bug: per-head vectors avoid cross-head interleaving
- CLI updated to use KV cache by default
- bench-gpt2 supports --no-cache flag for comparison

Benchmark results (50 prompts × 20 tokens):
- KV cache vs no-cache: 50/50 bit-identical (cache is correct)
- 18x speedup: TTFT 400→24ms, TBT 407→22ms, throughput 2.5→44 tok/s
- vs HF transformers: 40/50 match (10 are FP divergence, avg logit gap 0.20)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-05-21 23:39:41 +08:00
cb12250ef0 phase 8: add benchmark framework + baseline results
- bench-gpt2 binary: runs 50 prompts, measures TTFT/TBT per prompt, outputs JSON
- bench_compare.py: compares xserv vs transformers token-by-token + timing
- Baseline results: 50/50 correctness, 400ms TTFT / 407ms TBT (100x slower than PyTorch)
- Bottlenecks documented: no KV cache, CPU round-trips, cuBLAS handle churn

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-05-21 23:29:41 +08:00
9806b4db35 phase 0+1: project scaffold + xserv-cuda crate
- Cargo workspace with xserv-cuda crate
- CUDA FFI bindings (cudart: memory, stream, device, error)
- GpuBuffer RAII wrapper with H2D/D2H/D2D copy
- CudaStream wrapper with RAII Drop
- CachingAllocator with size-bucketed free lists
- PinnedBuffer for page-locked host memory
- Device info query via cudaDeviceGetAttribute
- Vector-add CUDA kernel smoke test
- Integration test suite (11 tests)
- build.rs: cc crate compiles .cu for SM 12.0
- sync-and-build.sh for remote build on dash5
- Roadmap doc (docs/00-roadmap.md) and Phase 0+1 design doc

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-05-21 18:40:22 +08:00