RTX 3090 vs RTX 4090: Specs, VRAM & Price
Short answer: pick the RTX 4090 when your workload uses FP8 quantization, or you just want the newer, faster card and the price gap is small enough. Pick the RTX 3090 when you're running BF16/FP32-only work and want the lowest possible hourly rate.
Both the RTX 3090 and the RTX 4090 ship with 24 GB of VRAM.
You can rent both by the hour, no purchase required. RTX 3090 from $0.220/GPU/hr; RTX 4090 from $0.416/GPU/hr. The RTX 3090 is 47% cheaper at the entry rate.
RTX 3090
Good for inference and small-scale training workloads
RTX 4090
Good for inference and light fine-tuning workloads
Last updated: 2026-11-03 UTCRefreshes every 6 hours
Specs side by side
| Spec | RTX 3090 | RTX 4090 |
|---|---|---|
| VRAM | 24 GB | 24 GB |
| Memory bandwidth | 936 GB/s | 1,008 GB/s |
| Architecture | Ampere | Ada Lovelace |
| Compute capability | 8.6 | 8.9 |
| Precisions in hardware | FP32, FP16, BF16, INT4 | FP32, FP16, BF16, FP8, INT4 |
| Peak FP16/BF16 tensor TFLOPS | 142 TFLOPS | – |
| NVLink / multi-GPU interconnect | NVLink, 2-way | – |
| Max board power (TDP) | 350W | 450W |
| Form factor | PCIe 4.0 x16 | PCIe 4.0 x16 |
| Regions | 2 | 3 |
On-demand price
| Rate | RTX 3090 | RTX 4090 |
|---|---|---|
| Lowest per GPU/hr | $0.220/GPU/hr (cheapest overall) | $0.416/GPU/hr (cheapest overall) |
Which is better for AI: RTX 3090 or RTX 4090?
The RTX 4090 has FP8 tensor cores the RTX 3090 lacks entirely, Ada Lovelace clears the FP8 floor while Ampere doesn't (lib/tools/gpu-capabilities.ts), which is the deciding factor for anyone doing quantized inference or fine-tuning rather than legacy BF16/FP32 work. Pick the RTX 4090 when your workload uses FP8 quantization, or you just want the newer, faster card and the price gap is small enough; pick the RTX 3090 when you're running BF16/FP32-only work and want the lowest possible hourly rate. On price the RTX 3090 undercuts the RTX 4090 by 47% at the entry rate ($0.220 vs $0.416/GPU/hr). Worth weighing if the deciding factor above isn't a hard requirement for your job.
Decision criteria
| Compute precision | RTX 4090 has FP8 tensor cores; RTX 3090 (Ampere) does not (lib/tools/gpu-capabilities.ts). |
| Architecture | Ampere (RTX 3090) vs Ada Lovelace (RTX 4090). |
| VRAM | 24 GB (RTX 3090) vs 24 GB (RTX 4090), live from current listings. |
| Availability | 2 region(s) list the RTX 3090 vs 3 for the RTX 4090. |
| Entry price | $0.220/GPU/hr (RTX 3090) vs $0.416/GPU/hr (RTX 4090). |
Pick the RTX 3090 when
- Your workload is BF16/FP32-only and gets nothing from FP8
- You want the lowest possible hourly rate for the job
- RTX 3090 supply is what's available in your region
Pick the RTX 4090 when
- Your workload benefits from FP8 quantization
- You want meaningfully more compute for a moderate price step-up
- You're doing anything training-adjacent where the newer generation helps
Price-performance
At list rates, 1,000 GPU-hours costs $220 on the RTX 3090 against $416 on the RTX 4090. Neither NVIDIA nor Aquanode publishes a workload-normalized $/token or $/epoch figure for this pair, so $/GPU-hour below is the only apples-to-apples number. A faster card can still cost less per finished job even at a higher hourly rate.
RTX 3090 vs RTX 4090: common questions
Is the RTX 3090 or the RTX 4090 better for AI?
Short answer: pick the RTX 4090 when your workload uses FP8 quantization, or you just want the newer, faster card and the price gap is small enough. Pick the RTX 3090 when you're running BF16/FP32-only work and want the lowest possible hourly rate.
Is the RTX 3090 or the RTX 4090 cheaper to rent?
On Aquanode's live marketplace the RTX 3090 starts at $0.220/GPU/hr (median $0.275/GPU/hr) and the RTX 4090 starts at $0.416/GPU/hr (median $0.837/GPU/hr). The RTX 3090 is the cheaper of the two at the entry rate, by 47%.
What is the difference between the RTX 3090 and the RTX 4090?
Both cards report 24 GB of VRAM; the RTX 3090 is an Ampere part and the RTX 4090 is Ada Lovelace (compute capability 8.6 vs 8.9); only the RTX 4090 supports FP8 compute. On price, the RTX 3090 lists from $0.220/GPU/hr and the RTX 4090 from $0.416/GPU/hr.
How widely available are the RTX 3090 and the RTX 4090?
The RTX 3090 is listed in 2 regions and the RTX 4090 in 3 regions right now.
How much does 1,000 GPU-hours cost on the RTX 3090 vs the RTX 4090?
At the lowest rates listed today, 1,000 GPU-hours costs $220 on the RTX 3090 and $416 on the RTX 4090, a difference of $196 for the same runtime. Rates are per GPU per hour and update hourly.
How much VRAM does the RTX 3090 have compared to the RTX 4090?
Both the RTX 3090 and the RTX 4090 ship with 24 GB of VRAM.
Is the RTX 3090 still worth renting over the RTX 4090?
Mainly on price. The RTX 3090 has no FP8 tensor cores at all, so if your workload can use FP8 the RTX 4090 is the clear pick. Today the RTX 3090 lists from $0.220/GPU/hr against the RTX 4090's $0.416/GPU/hr on Aquanode, worth it only if that gap outweighs the missing FP8 support for your job.
Does the RTX 3090 or the RTX 4090 support NVLink?
The RTX 3090 supports NVLink, 2-way; the RTX 4090 has no dedicated GPU-to-GPU interconnect.
How this comparison is calculated
Every price is normalized to a per-GPU hourly rate using the same pipeline as every other pricing surface on Aquanode, and only the cheapest qualifying offer per provider is shown. A dash means that provider does not currently list that GPU.
Architecture, compute capability and supported precisions come from each vendor's published datasheet for that generation, not from the marketplace feed. This page regenerates at most once per hour.
Memory bandwidth, tensor TFLOPS, NVLink/interconnect and max board power are the same verified-from-datasheet figures shown on each model's own RTX 3090 page and RTX 4090 page, which link the primary vendor source for that model. A dash here means Aquanode hasn't verified that figure from a primary source yet, never a guess.
Go further
Check what fits in each card's memory with the RTX 3090 VRAM calculator and the RTX 4090 VRAM calculator, or browse every model by generation in the GPU index.
More RTX 3090 comparisons
More RTX 4090 comparisons
Related reading: RTX 3090 pricing and specs, and RTX 3090 for AI.
