llamaperf

AMD RX 7900 XTX vs AMD RX 9070 for local LLMs

47 reports on the AMD RX 7900 XTX and 9 on the AMD RX 9070

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 1.5x higher on the AMD RX 7900 XTX (960 GB/s on the AMD RX 7900 XTX, 640 on the AMD RX 9070). The estimates below compare them on the models people run most.

AMD RX 7900 XTX
Memory
24GB
Memory bandwidth
960 GB/s
FP16 compute
123 TFLOPS
Reports
47
AMD RX 9070
Memory
16GB
Memory bandwidth
640 GB/s
FP16 compute
145 TFLOPS
Reports
9

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 RX 7900 XTXAMD RX 9070
Qwen3.8 27B34.8 t/sQ4_K_M41.7 t/sQ2_K
Qwen3.8 125B · 6B active19.5 t/sQ2_K, experts in RAMdoesn't fit at these settings
Qwen3.6 35B · 3B active123.2 t/sQ4_K_S138.0 t/sQ2_K
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 27B34.8 t/sQ4_K_M41.7 t/sQ2_K
Gemma 4 26B · 4B active78.4 t/sQ5_K_S93.0 t/sQ3_K_S

Change the context, RAM or model in the calculator: AMD RX 7900 XTX · AMD RX 9070

Every report on each card, with its source: AMD RX 7900 XTX · AMD RX 9070

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