KV cache quantization benchmarks: TurboQuant is overrated, q5 deserves attention, q8 may waste VRAM

Here are my KV cache quantization benchmarks: TurboQuant is overrated but saved by TCQ, q5 deserves more attention, and symmetric q8 might be a waste of VRAM

Anbeeld benchmarked KV cache quantization for Qwen 3.6 27B on one RTX 3090 at 64k and 128k context, reporting q4_0 tail KLD 32% worse than q5_0 and turbo4 running 17% slower than q4_0 with little memory saving.

Why it matters: HKR-H/K/R all pass, with a first-person benchmark and concrete deltas. Scope is narrow: one RTX 3090, one model, and a Reddit source, so it stays near the featured threshold.