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Can I run Mixtral 8x7B (MoE) on Apple M4 Max (128GB)?

Yes: Mixtral 8x7B (MoE) runs on Apple M4 Max (128GB) with Q8_0 at roughly 24 tokens/s. Estimated memory 48.8 GiB at 8,192 tokens of context.

With Q8_0 you can push the context to about 32,768 tokens before memory runs out (F16 KV cache).

Memory by quantisation (8,192-token context)

QuantisationMemoryVerdictEst. speed
F16Unquantized reference89.6 GiBTight~13 tok/s
Q8_0Near-lossless48.8 GiBFits~24 tok/s
Q6_KVery close to F1638.3 GiBFits~30 tok/s
Q5_K_MGreat quality/size33.5 GiBFits~35 tok/s
Q4_K_MBest default for most29.0 GiBFits~40 tok/s
IQ4_XSSmaller 4-bit (imatrix)25.7 GiBFits~45 tok/s
Q3_K_MNoticeable loss23.9 GiBFits~48 tok/s
Q2_KLast resort; big loss20.8 GiBFits~55 tok/s

Apple M4 Max (128GB) offers about 128 GiB of memory (75% usable for a model) at 546 GB/s. Speed is a bandwidth-bound estimate of single-stream generation at 65% efficiency; real results vary by runtime, drivers and settings, so measure on your machine.

How this is calculated

Weights โ‰ˆ parameters ร— bits per weight รท 8. KV cache โ‰ˆ 2 ร— 32 layers ร— 8 KV heads ร— 128 head dim ร— 2 bytes per token. Decode speed โ‰ˆ efficiency ร— memory bandwidth รท bytes read per token (this is a mixture-of-experts model, so only the active parameters are read, but all of them must fit in memory). Learn the maths in VRAM math and memory bandwidth, or try the VRAM calculator.

Running slowly or out of memory? See CUDA out of memory and the quantisation lesson.