// RUN โ€” FITS

Can the AMD Instinct MI455X run OPT-66B?

Yes โ€” here's how fast and up to what context, with real measured numbers.

OPT-66B on the AMD Instinct MI455X

QuantFits?Max contextSpeedBeyond context
FP16 yes 805k 93.5-114.3 t/s ~0.2-0.2 (slow)
Q8 yes 1007k 187.1-228.7 t/s ~0.4-0.5 (slow)
Q4 yes 1096k 334.1-408.3 t/s ~0.7-0.8 (slow)

Estimate (memory-bound). Beyond "max context" the KV cache spills to system RAM offload (depends on your system RAM) and speed drops to the "beyond" figure.

FAQ

Can the AMD Instinct MI455X run OPT-66B?โ–ถ

Yes. At Q4 it generates ~334.1-408.3 tok/s and fits up to 1096k context; beyond that it spills to system RAM offload (depends on your system RAM) and slows to ~0.7-0.8 tok/s.

How much context fits?โ–ถ

At Q4, up to about 1096k tokens stay in fast memory; longer context spills to system RAM offload (depends on your system RAM) and throughput collapses.