RTX 3090 vs RTX 4000 SFF Ada: Specs, VRAM & Price
Short answer: choose the RTX 3090 when 24 GB of VRAM is the gating requirement. Choose the RTX 4000 SFF Ada when 20 GB is enough for the workload and availability points that way.
The RTX 3090 has 24 GB of VRAM; the RTX 4000 SFF Ada has 20 GB.
You can rent both by the hour, no purchase required. RTX 3090 from $0.185/GPU/hr; RTX 4000 SFF Ada from $0.198/GPU/hr. The RTX 3090 is 7% cheaper at the entry rate.
RTX 3090
Good for inference and small-scale training workloads
RTX 4000 SFF Ada
Good for inference and light fine-tuning workloads
Last updated: 2026-10-10 22:02:52 UTCRefreshes hourly
Specs side by side
| Spec | RTX 3090 | RTX 4000 SFF Ada |
|---|---|---|
| VRAM | 24 GB | 20 GB |
| Memory bandwidth | 936 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 | – |
| Form factor | PCIe 4.0 x16 | – |
| Regions | 4 | 1 |
On-demand price
| Rate | RTX 3090 | RTX 4000 SFF Ada |
|---|---|---|
| Lowest per GPU/hr | $0.550/GPU/hr | $0.198/GPU/hr (cheapest overall) |
Which is better for AI: RTX 3090 or RTX 4000 SFF Ada?
Choose the RTX 3090 when 24 GB of VRAM is the gating requirement. Choose the RTX 4000 SFF Ada when 20 GB is enough for the workload and availability points that way.
RTX 3090 vs RTX 4000 SFF Ada: common questions
Is the RTX 3090 or the RTX 4000 SFF Ada better for AI?
Short answer: choose the RTX 3090 when 24 GB of VRAM is the gating requirement. Choose the RTX 4000 SFF Ada when 20 GB is enough for the workload and availability points that way.
Is the RTX 3090 or the RTX 4000 SFF Ada cheaper to rent?
On Aquanode's live marketplace the RTX 3090 starts at $0.185/GPU/hr (median $0.242/GPU/hr) and the RTX 4000 SFF Ada starts at $0.198/GPU/hr (median $0.198/GPU/hr). The RTX 3090 is the cheaper of the two at the entry rate, by 7%.
What is the difference between the RTX 3090 and the RTX 4000 SFF Ada?
The RTX 3090 has 24 GB of VRAM against the RTX 4000 SFF Ada's 20 GB; the RTX 3090 is an Ampere part and the RTX 4000 SFF Ada is Ada Lovelace (compute capability 8.6 vs 8.9); only the RTX 4000 SFF Ada supports FP8 compute. On price, the RTX 3090 lists from $0.185/GPU/hr and the RTX 4000 SFF Ada from $0.198/GPU/hr.
How widely available are the RTX 3090 and the RTX 4000 SFF Ada?
The RTX 3090 is listed in 4 regions and the RTX 4000 SFF Ada in 1 region right now.
How much does 1,000 GPU-hours cost on the RTX 3090 vs the RTX 4000 SFF Ada?
At the lowest rates listed today, 1,000 GPU-hours costs $185 on the RTX 3090 and $198 on the RTX 4000 SFF Ada, a difference of $13 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 4000 SFF Ada?
The RTX 3090 has 24 GB of VRAM; the RTX 4000 SFF Ada has 20 GB.
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 4000 SFF Ada 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 4000 SFF Ada VRAM calculator, or browse every model by generation in the GPU index.
More RTX 3090 comparisons
More RTX 4000 SFF Ada comparisons
Related reading: RTX 3090 pricing and specs, and RTX 3090 for AI.
