RTX 4090 or A100 PCIe?
Both are dedicated, both are monthly, both open without an identity check. What separates them is memory, bandwidth and $199 a month — and which of those matters depends entirely on what you intend to run.
- $193/moRTX 4090, one card
- $392/moA100 PCIe, one card
- 24 vs 40 GBmemory per card
- 1.5×bandwidth gap
The short answer
Which one, and when
- Pick the RTX 4090
- when 24 GB holds your model. It saves $199/month, and memory you do not use is memory you paid for.
- Pick the A100 PCIe
- when your model needs more than 24 GB on a single card. That is a threshold, not a preference — below it, the extra $199/month buys you nothing.
- Neither, if
- your model does not fit on a single card of either. Sharding costs synchronisation at every layer — see the interconnect guide before buying a multi-GPU node.
Side by side
| RTX 4090 | A100 PCIe | Difference | |
|---|---|---|---|
| Architecture | Ada Lovelace | Ampere | Ada Lovelace is a different generation |
| Memory per card | 24 GB GDDR6X | 40 GB HBM2 | 16 GB in favour of the A100 PCIe |
| Memory bandwidth | 1,008 GB/s | 1,555 GB/s | 1.54× in favour of the A100 PCIe |
| Form factor | PCIe add-in card | PCIe add-in card | Same |
| Node sizes | 1×, 2×, 4×, 8× | 1×, 2×, 4×, 8× | Up to 320 GB in one node |
| From, per month | $193 | $392 | $199/month apart |
Price at every node size
| Node | RTX 4090 | A100 PCIe | Total VRAM | |
|---|---|---|---|---|
| 1 × GPU | $193/mo | $392/mo | 24 GB / 40 GB | RTX 4090 A100 PCIe |
| 2 × GPU | $416/mo | $802/mo | 48 GB / 80 GB | RTX 4090 A100 PCIe |
| 4 × GPU | $814/mo | $1,556/mo | 96 GB / 160 GB | RTX 4090 A100 PCIe |
| 8 × GPU | $1,579/mo | $2,983/mo | 192 GB / 320 GB | RTX 4090 A100 PCIe |
What each one holds on a single card
At 8k context, best precision that fits. This is the difference that decides a purchase — not the specification sheet.
Only the RTX 4090
Nothing. Every model the RTX 4090 holds on one card, the A100 PCIe holds too — the difference between them is speed, not capability.
Only the A100 PCIe
Nothing. The RTX 4090 holds everything the A100 PCIe does.
Cost per GB and per TB/s
Two ratios that cut through the specification sheet. The first tells you what memory costs; the second what speed costs.
| Card | $/GB of VRAM, per month | $/TB per second, per month | Better at |
|---|---|---|---|
| RTX 4090 | $8.04 | $191 | Both ratios |
| A100 PCIe | $9.80 | $252 | Neither |
These ratios rank cards; they do not choose one. A card that is cheaper per gigabyte is worthless if it has too few gigabytes to hold your model at all — capacity is a threshold, not a slope. Use them to break a tie between two cards that both fit.
RTX 4090 against A100 PCIe, in short
Is the RTX 4090 worth the extra money over the A100 PCIe?
Which one is faster for LLM inference?
Do both come as multi-GPU nodes?
Can I rent either without an identity check?
Other comparisons
Both are racked and waiting, in all 6 data centres.
Whichever you pick, it is monthly, paid in crypto, opened without an identity check and delivered in under 5 minutes.