A100 80GB vs H100 80GB
Both hold the same 80 GB, so the split is speed: the H100 80GB has about 1.6× the memory bandwidth. Decode speed on a memory-bound workload scales with bandwidth, so that ratio is the number that matters once the model fits at all.
Specs side by side
| Spec | A100 80GB | H100 80GB |
|---|---|---|
| VRAM | 80 GB | 80 GB |
| Memory bandwidth | 2039 GB/s | 3350 GB/s |
| TDP | 400 W | 700 W |
| Models that fit (Q4_K_M) | 473 of 506 | 473 of 506 |
Form factor: A100 80GB figures are for the SXM4 module, H100 80GB figures are for the SXM5 module. PCIe/NVL variants differ in bandwidth and TDP — see the A100 80GB page and methodology.
What the extra VRAM actually buys
Nothing, in model-fit terms: every model in our catalog that fits the H100 80GB at Q4_K_M also fits the A100 80GB. The extra capacity goes to longer context, bigger batches and higher-precision quantization — not to a larger model tier.
Largest model each can run
At Q4_K_M the biggest fit in our catalog is Pixtral Large 124B Instruct (74.3 GB) on the A100 80GB, and Pixtral Large 124B Instruct (74.3 GB) on the H100 80GB. Both figures are weights plus runtime overhead; KV cache for your context is extra.
Power and running cost
At 8 hours a day the A100 80GB draws about 96 kWh a month against 168 kWh for the H100 80GB — a difference of 72 kWh. Multiply by your own tariff; we do not assume one. Board TDP is the rated figure, not measured draw.
FAQ
A100 80GB vs H100 80GB: which should I buy for local AI?
The H100 80GB fits 473 of the 506 models in our catalog at Q4_K_M against 473 for the A100 80GB, and has about 1.6× the memory bandwidth, which is what sets decode speed once a model fits. If the models you run already fit the A100 80GB, the extra spend buys context length and speed, not a new model tier.
Is the H100 80GB faster than the A100 80GB?
On memory-bound decoding, yes — roughly 1.6× the throughput, since token generation scales with memory bandwidth (3350 GB/s vs 2039 GB/s). This is an upper bound from bandwidth alone, not a measured benchmark.
How much more VRAM does the H100 80GB have?
Neither has more — both carry 80 GB. No model in our catalog needs the difference at Q4_K_M.
Need a third card in the mix? The interactive compare tool lines up any three. To size KV cache for your context length, use the GPU Memory Calculator.
Related matchups
Other head-to-heads involving these cards:
A100 40GB vs A100 80GBH100 80GB vs H200 141GBRTX 4090 vs H100 80GBRTX 5090 vs H100 80GBRTX A6000 vs A100 80GB
New to sizing? What VRAM is and why bandwidth sets decode speed cover the basics, and quantization explains the formats in the table above. Common mistakes when sizing VRAM lists the traps.