llamaperf

AMD Instinct MI250 vs AMD Instinct MI300X 192GB for local LLMs

0 reports on the AMD Instinct MI250 and 1 on the AMD Instinct MI300X 192GB

Which is faster for local LLMs?

Nobody has reported the same model at the same quant on both cards yet, so there's no measured head-to-head. Memory bandwidth, which caps how fast a card can write, is 1.6x higher on the AMD Instinct MI300X 192GB (3,277 GB/s on the AMD Instinct MI250, 5,300 on the AMD Instinct MI300X 192GB). The estimates below compare them on the models people run most.

AMD Instinct MI250
Memory
128GB
Memory bandwidth
3,277 GB/s
FP16 compute
362.1 TFLOPS
Reports
0
AMD Instinct MI300X 192GB
Memory
192GB
Memory bandwidth
5,300 GB/s
FP16 compute
1307 TFLOPS
Reports
1

Estimated by the calculator

The quant the calculator recommends for each card and its estimated speed at a 32,768-token context with 32 GB of system RAM, from memory bandwidth and the model's shape.

ModelAMD Instinct MI250AMD Instinct MI300X 192GB
Qwen3.8 27B33.4 t/sFP1654.0 t/sFP16
Qwen3.8 125B · 6B active119.8 t/sQ6_K184.6 t/sQ8_0
DeepSeek V4 Flash 284B · 13B active318.1 t/sQ2_K243.3 t/sQ4_K_M
Qwen3.6 35B · 3B active120.1 t/sFP16194.3 t/sFP16
Qwen3.6 27B33.4 t/sFP1654.0 t/sFP16
Gemma 4 26B · 4B active90.1 t/sFP16145.8 t/sFP16

Change the context, RAM or model in the calculator: AMD Instinct MI250 · AMD Instinct MI300X 192GB

Every report on each card, with its source: AMD Instinct MI250 · AMD Instinct MI300X 192GB

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