Q: How fast is gpt-oss 20B MoE on the AMD Instinct MI455X 432GB?

~3100–5000 tok/s (active-expert estimate) on the AMD Instinct MI455X 432GB. computed roofline: 23300 GB/s × 0.28–0.45 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 AMD Instinct MI455X 432GB 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 AMD Instinct MI455X 432GB offers ~432GB usable — verdict: full. 14.2 GB needed of 432 GB usable — headroom for context

Question 2

How fast is gpt-oss 20B MoE on the AMD Instinct MI455X 432GB?

Accepted Answer

~3100–5000 tok/s (active-expert estimate)

computed roofline: 23300 GB/s × 0.28–0.45 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 M40 (24GB, used) runs it fully ($50).

Can the AMD Instinct MI455X 432GB run gpt-oss 20B MoE?

Run gpt-oss 20B MoE on instead