Learn AI by Building

From your first dataset to production agents โ€” deep-dive series, hands-on notebooks, and experiments you can rerun yourself.

Paper of the Week

All Issues โ†’
Issue #3 ยท WeeklySep 9, 2026

Paper of the Week #3 โ€” Half the FLOPs Is Not Half the Time

One integer halves a fine-grained MoE's expert compute (arXiv 2609.04575) and its Table 5 replicates on one A100 to within a point. The paper never reports time, so I measured it: nothing in HF transformers, nothing at batch 1 in the vLLM you run today, 1.35x at batch 8. Plus the OLMoE control and the iso-cost harness control promised in issue #2.

Premium Series

Our Products

Courses and starter kits built from what we measure here

Starter Kits

View All โ†’

Practice notebooks, interview questions, and project solutions โ€” ready to download.

Browse Starter Kits

Latest Posts

View All โ†’
llama.cpp KV Cache Quantization: Why q8_0 Costs 9% of Throughput โ€” or 22%

llama.cpp KV Cache Quantization: Why q8_0 Costs 9% of Throughput โ€” or 22%

Mainline llama.cpp on one A100, Qwen3-8B Q4_K_M, llama-server with 1 to 32 concurrent slots. On a 32K prompt, q8_0 cost 9% of server throughput when each request generated 128 tokens and 22% when it generated 1,024, because prefill dominates the short case and prefill is unaffected by the KV type. Per-token decode was 34% slower, matching llama-bench. VRAM in use after startup fell from 41.0 GiB to 25.1 GiB at four 64K slots.

- Models & Algorithms
Read More
llama.cpp KV Cache Quantization, Measured on One A100 โ€” q8_0 Is Free at 4K and Costs Half Your Decode Speed at 64K

llama.cpp KV Cache Quantization, Measured on One A100 โ€” q8_0 Is Free at 4K and Costs Half Your Decode Speed at 64K

Mainline llama.cpp, Qwen3-8B, one A100: -ctk q8_0 -ctv q8_0 matches f16 perplexity and cuts the 32K cache by 2.1 GiB, but decode at 64K depth drops to 55% of f16 (q4_0: 50%). Two other settings, q5_1 and a q8_0/q4_0 mix, silently ran prefill on the CPU at 43 and 63 tokens per second.

- Models & Algorithms
Read More
KV Cache Reduction, Measured on One A100 โ€” Part 1: The Twelve Techniques Don't Pay in the Same Currency

KV Cache Reduction, Measured on One A100 โ€” Part 1: The Twelve Techniques Don't Pay in the Same Currency

Every list of KV cache techniques presents a dozen of them as peers. On one A100 the spread is enormous: prefix reuse cut a shared-prefix workload from 59.4s to 6.2s, while tuning the paged block size moved capacity by under 1%. The reason you cannot rank them on one number is that they pay out in different units.

- Models & Algorithms
Read More
Paper of the Week #3 โ€” Half the FLOPs Is Not Half the Time

Paper of the Week #3 โ€” Half the FLOPs Is Not Half the Time

One integer halves a fine-grained MoE's expert compute (arXiv 2609.04575) and its Table 5 replicates on one A100 to within a point. The paper never reports time, so I measured it: nothing in HF transformers, nothing at batch 1 in the vLLM you run today, 1.35x at batch 8. Plus the OLMoE control and the iso-cost harness control promised in issue #2.

- AI Research
Read More
The paper stopped at half the experts. A quarter loses four points instead of thirty, and a model trained without renormalization tells you why.

The paper stopped at half the experts. A quarter loses four points instead of thirty, and a model trained without renormalization tells you why.

Two cells arXiv:2609.04575 never ran: kโ‚=2 and kโ‚=3 on Qwen3.6-35B-A3B, and the whole kโ‚‚ trick on OLMoE, which was trained without renormalization. The second one is a clean test of the paper's mechanism.

- AI Research
Read More
One integer halves MoE expert compute. We measured the speed the paper didn't: free at batch 8, not at batch 1.

One integer halves MoE expert compute. We measured the speed the paper didn't: free at batch 8, not at batch 1.

We reproduced Table 5 of arXiv:2609.04575 on one A100 and measured the throughput the paper leaves out: nothing in HF transformers, nothing at batch 1 in stock vLLM, 1.35ร— at batch 8.

- AI Research
Read More