~/llamay $ llamay bench -m qwen2.5:0.5b -gpu -forks 32 -prompt 2048 -gen 32 -reps 1
llamay v0.1.58-1-gb14f550 · Qwen2.5 0.5B Instruct · qwen2 · 7 threads · kernels neon+i8mm ·
matmul metal:Apple M4 · gemm own kernels · kv f32
weights 373.71 MiB · repack on · context 32768 · prompt 2048 · generate 32

phase     rate          best     note
prefill   650.4 tok/s   3.149s   one command buffer per 256-token tile
decode    41.7 tok/s    768ms    506 dispatches per token, one submission

cpu encoding 40ms · gpu execution 3.854s (1% encoding)

phase      rate    best   note
fork x32   65µs           0 pages allocated (a copy would be 1024)
snapshot   129ms          48.01 MiB for 2048 tokens, at f32
restore    74ms           vs 3.149s to re-prefill

gpu time: staging 149ms · kernels 9.77s · copy-back 191ms

Restoring a 2048-token context is 42.6x faster than recomputing it.
~/llamay $ # 0 pages allocated where a copy would have been 1024 — that is the fork