llamaperf

NVIDIA A800 40GB vs NVIDIA RTX 4090 for local LLMs

0 reports on the NVIDIA A800 40GB and 57 on the NVIDIA RTX 4090

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 NVIDIA A800 40GB (1,555 GB/s on the NVIDIA A800 40GB, 1,008 on the NVIDIA RTX 4090). The estimates below compare them on the models people run most.

NVIDIA A800 40GB
Memory
40GB
Memory bandwidth
1,555 GB/s
FP16 compute
312 TFLOPS
Reports
0
NVIDIA RTX 4090
Memory
24GB
Memory bandwidth
1,008 GB/s
FP16 compute
330 TFLOPS
Reports
57

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.

ModelNVIDIA A800 40GBNVIDIA RTX 4090
Qwen3.8 27B31.7 t/sQ8_036.5 t/sQ4_K_M
Qwen3.8 125B · 6B active16.8 t/sQ3_K_S, experts in RAM19.6 t/sQ2_K, experts in RAM
Qwen3.6 35B · 3B active125.3 t/sQ6_K129.3 t/sQ4_K_S
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 27B31.7 t/sQ8_036.5 t/sQ4_K_M
Gemma 4 26B · 4B active81.5 t/sQ8_082.3 t/sQ5_K_S

Change the context, RAM or model in the calculator: NVIDIA A800 40GB · NVIDIA RTX 4090

Every report on each card, with its source: NVIDIA A800 40GB · NVIDIA RTX 4090

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