How much VRAM does Mixtral 8x22B need?

Mixtral 8x22B (141B parameters) requires approximately 95.0 GB of memory with Q4_K_M quantization.

What is the best quantization for Mixtral 8x22B?

The recommended quantization for Mixtral 8x22B is Q4_K_M, which balances quality and memory efficiency.

Can it run?

No, Mixtral 8x22B requires more memory than RX 7900 XT 20GB provides.

FWon't run

Too heavy

Using Q4_K_M in llama.cpp

Capabilities:

Fit status

Too heavy

Decode

12.8 tok/s

TTFT

15070 ms

Safe context

Memory

95.0 GB / 20.0 GB

Weights86.0 GB

KV Cache6.1 GB

Runtime0.9 GB

Headroom2.0 GB

Workload	Grade	Fit	Decode	TTFT	Context
Agentic Coding	F	Too heavy	10.7 tok/s	26303 ms	6K
Chat	F	Too heavy	10.7 tok/s	9864 ms	4K
Coding	F	Too heavy	12.8 tok/s	15070 ms	4K
RAG	F	Too heavy	10.7 tok/s	32879 ms	6K
Reasoning	F	Too heavy	10.7 tok/s	21371 ms	4K

How Mixtral 8x22B (141B params) fits at each quantization level on RX 7900 XT 20GB (20.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	55.0 GB	Low	F0
Q3_K_S	3	69.1 GB	Low	F0
NVFP4	4

Upgrade options

MacBook Pro M3 Max 128GBBest value

D5.1 tok/s decode

~$2,499 MSRP

AMD Instinct MI350X 288GBBudget pick

C130.3 tok/s decode

~$8,000 MSRP