NVIDIA A800 PCIe 80GB vs NVIDIA GeForce RTX 3090 24GB

The A800 is the newer part: Ampere, launched in 2022, against the GeForce RTX 3090's Ampere from 2020. Newer architectures typically add lower-precision formats and better throughput per watt, so check the precision rows your workload actually uses.

Dense throughput for the A800 against the GeForce RTX 3090: FP64 9.7 vs 0.6 TFLOPS, FP32 20 vs 36 TFLOPS, FP16 312 vs 71 TFLOPS. Sparse figures, where the vendor publishes them, appear under each dense number in the performance table.

Memory is 80 GB against 24 GB, fed at 1.9 TB/s versus 936 GB/s. More memory per GPU means larger models fit before you have to shard across cards, which often matters more than raw TFLOPS for inference.

Power budgets are 300 W for the A800 and 350 W for the GeForce RTX 3090. At FP32 that works out to 0.07 against 0.10 TFLOPS per watt.

For LLM training and inference, weight the FP8 and FP16 rows and memory capacity most heavily. For scientific and HPC workloads, the FP64 row is the one to read.