Gemma 4 QAT handles KV cache quantization MUCH better, KLD benchmarks show

Link to the article: KV Cache Quantization on Gemma 4 31B: Non-QAT vs QAT

KLD benchmarks with BeeLlama.cpp v0.4.3, fork of llama.cpp with more KV cache quantization options, comparing Gemma Q4_0 non-QAT vs Gemma Q4_0 QAT. Long story short: QAT is much more friendly to KV cache quantization, moving same-top agreement from "different model" to "that looks like Gemma 4?"

This confirms results from previous posts on this subreddit:

• Gemma 4 QAT seems to respond significantly better to KV cache quantization
• Gemma 4 QAT 31B responds better to KV cache quantization too

Comparison of standard quants

Full benchmark results, setup, method, analysis, explanations and everything else can be found in the article.