Q: How fast is gpt-oss 20B MoE on the CPU-only (DDR3 dual-channel)?

~5.5–8.5 tok/s (active-expert estimate) on the CPU-only (DDR3 dual-channel). computed roofline: 25.6 GB/s × 0.45–0.70 efficiency window / 2.1GB (Q4_K_M) — bands, never points. MoE: file is 14GB (that decides fit) but only ~3B of experts activate per token (~2.1GB streamed) — band below is the active-expert estimate, optimistic; community MoE rows run several× the naive bandwidth math

Question 1

Can the CPU-only (DDR3 dual-channel) run gpt-oss 20B MoE?

Accepted Answer

gpt-oss 20B MoE needs about 14.19GB working set (weights 14GB + KV cache 0.19GB at 4k context). The CPU-only (DDR3 dual-channel) offers ~6GB usable — verdict: no. 14.2 GB vs 6 GB usable — does not fit

Question 2

How fast is gpt-oss 20B MoE on the CPU-only (DDR3 dual-channel)?

Accepted Answer

~5.5–8.5 tok/s (active-expert estimate)

computed roofline: 25.6 GB/s × 0.45–0.70 efficiency window / 2.1GB (Q4_K_M) — bands, never points.

MoE: file is 14GB (that decides fit) but only ~3B of experts activate per token (~2.1GB streamed) — band below is the active-expert estimate, optimistic; community MoE rows run several× the naive bandwidth math

Question 3

What should I run gpt-oss 20B MoE on instead?

Accepted Answer

Tesla P40 (24GB, used) runs it fully ($290).

Can the CPU-only (DDR3 dual-channel) run gpt-oss 20B MoE?

Run gpt-oss 20B MoE on instead