// RUN โ€” FITS

Can the Apple M4 Max 36GB run NeMO Megatron GPT 20B?

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

NeMO Megatron GPT 20B on the Apple M4 Max 36GB

QuantFits?Max contextSpeedBeyond context
FP16 no โ€” โ€” โ€”
Q8 yes 42k 18.6-22.4 t/s ~0.3-0.4 (slow)
Q4 yes 75k 33.2-40 t/s ~0.6-0.7 (slow)

Estimate (memory-bound). Beyond "max context" the KV cache spills to SSD swap and speed drops to the "beyond" figure.

FAQ

Can the Apple M4 Max 36GB run NeMO Megatron GPT 20B?โ–ถ

Yes. At Q4 it generates ~33.2-40 tok/s and fits up to 75k context; beyond that it spills to SSD swap and slows to ~0.6-0.7 tok/s.

How much context fits?โ–ถ

At Q4, up to about 75k tokens stay in fast memory; longer context spills to SSD swap and throughput collapses.