A100 80GB vs RTX 4090: Which GPU Should You Choose?
We checked current provider listings and official hardware specifications to show when A100 80GB or RTX 4090 is the better fit for your workload.
Choose A100 80GB when its larger memory avoids a multi-GPU setup, choose RTX 4090 when the workload fits on one card at an A-to-B on-demand price ratio of 2.14, except when you need NVLink.
Before committing, run the same representative job once on each GPU at the live table’s on-demand minimums of $0.60 for A100 80GB and $0.28 for RTX 4090, then compare the actual cost per completed job.
Today's prices
USD/hr · 1× GPU · lowest on-demand price per provider
| Provider | A100 80GB | RTX 4090 |
|---|---|---|
| Vast.ai | $0.60 | $0.28 |
| Hyperstack | $1.35 · Not reported | Not offered |
| RunPod | $1.39 | $0.74 |
| Jarvislabs | $1.49 · Not reported | Not offered |
| DataCrunch | $1.79 | Not offered |
| Crusoe | $2.00 · Not reported | Not offered |
What your workload needs
Find your parameter count on the model's Hugging Face card. Serving maps to the inference rows, training to the fine-tuning rows.
| Workload | VRAM needed | A100 80GB | RTX 4090 | Cheapest today |
|---|---|---|---|---|
| 70B Q4 inference | 42 GB | 1× $0.60/hr | 2× $0.28/hr | RTX 4090 ×2 → $0.56/hr (est.) |
| 70B FP16 inference | 168 GB | 3× $0.60/hr | 7× $0.28/hr | A100 80GB ×3 → $1.8/hr (est.) |
| 70B QLoRA | 46 GB | 1× $0.60/hr | 2× $0.28/hr | RTX 4090 ×2 → $0.56/hr (est.) |
| 7B full fine-tune | 112 GB | 2× $0.60/hr | 5× $0.28/hr | A100 80GB ×2 → $1.2/hr (est.) |
| 70B FP8 training | 154 GB | unsupported | 7× $0.28/hr | RTX 4090 ×7 → $1.96/hr (est.) |
| Downshift recommendation | 42 GB | 1× $0.60/hr | 2× $0.28/hr | A100 80GB ×1 → $0.6/hr |
What the numbers say
A100 80GB has an on-demand minimum of $0.60, while RTX 4090 has an on-demand minimum of $0.28. That makes RTX 4090 the direct price choice when the workload fits on one card, but A100 80GB can be the better job-level value when its larger memory avoids a multi-GPU setup.
A100 80GB looks stronger for compute-bound BF16 work: vendor peak specifications imply an A-to-B performance ratio of 1.89, producing a modeled on-demand cost-per-job ratio of 1.13 versus RTX 4090. Actual throughput may differ with the model, software stack, and utilization.
A100 80GB is suited to BF16 or FP32 workloads within 80GB VRAM, while RTX 4090 covers FP8, BF16, or FP32 workloads within 24GB VRAM. FP8 therefore directs you to RTX 4090, while BF16 or FP32 jobs that exceed its memory ceiling but fit on A100 80GB favor the larger card; otherwise, RTX 4090 is the rational on-demand price choice.
Before you rent
Marlin matches your workload requirements to the lowest-priced suitable GPU available across major cloud providers.
Source coverage is limited to the listed provider pricing pages and official hardware specifications, with freshness shown separately on the page. Prices and availability can change quickly, while performance and workload-cost comparisons are modeled estimates whose assumptions may not match measured results. https://vast.ai/pricing · https://www.paperspace.com/pricing · https://www.tensordock.com/host-pricing · https://www.runpod.io/pricing · https://datacrunch.io/pricing · https://www.nvidia.com/content/dam/en-zz/Solutions/Data-Center/a100/pdf/nvidia-a100-datasheet-us-nvidia-1758950-r4-web.pdf · https://www.nvidia.com/en-us/geforce/graphics-cards/40-series/rtx-4090/ · https://lambda.ai/service/gpu-cloud · https://www.hyperstack.cloud/gpu-pricing · https://jarvislabs.ai/pricing
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