NVIDIA GeForce RTX 4090, 24GB vs NVIDIA GeForce RTX 3090, 24GB for local AI
Both hold 29 of the 50 current models here. The GeForce RTX 3090, 24GB costs $100 less, both priced as the card alone, without the PC around either. On Qwen3.8 27B, the strongest model both hold, the GeForce RTX 4090, 24GB is about 1.2× faster: 44 tok/s against 38, both estimated from memory bandwidth. The GeForce RTX 3090, 24GB pays for itself sooner, in 94 years against 104 years at 500k tokens a day. Both are previous-generation parts, so every figure here is priced at what they launched at rather than at prices you can pay today.
| NVIDIA GeForce RTX 4090, 24GB | NVIDIA GeForce RTX 3090, 24GB | |
|---|---|---|
| Price | $1,599card only | $1,499card only |
| Memory | 24 GB | 24 GB |
| Usable by the GPU | 23 GB | 23 GB |
| Memory bandwidth | 1008 GB/s | 936 GB/s |
| Power under load | 450 W | 350 W |
| Models that fit | 29 | 29 |
| Best model it runs | Qwen3.8 27B | Qwen3.8 27B |
| Speed on that model | 44 tok/s estimated | 38 tok/s estimated |
| Pay-back on that model | Pays back in 104 years | Pays back in 94 years |
Run the numbers on the NVIDIA GeForce RTX 4090, 24GB · or the NVIDIA GeForce RTX 3090, 24GB
How much use it takes to pay back
Everything above is at 500k tokens a day. Pay-back moves with how much you actually run, so here are both machines on Qwen3.8 27B, the strongest model both hold, at the five levels of use the calculator names. The NVIDIA GeForce RTX 3090, 24GB pays back sooner at every level of use, so this is not a choice that turns on how hard you work it.
| A day's use | NVIDIA GeForce RTX 4090, 24GB | NVIDIA GeForce RTX 3090, 24GB |
|---|---|---|
| 50ka few chats a day | 1,037 years | 940 years |
| 200klight assistant use | 259 years | 235 years |
| 1Ma moderate coding-assistant day | 52 years | 47 years |
| 4Mheavy coding with an agent | 13 years | 12 years |
| 20Magents running most of the day | 2.6 years | 2.4 years |
Run the NVIDIA GeForce RTX 4090, 24GB at 20M tokens a day · or the NVIDIA GeForce RTX 3090, 24GB
Memory is not what separates them
Every model on this list that fits one machine fits the other, and not only at 32k of context: across all 50 models the calculator counts, at every context from 4k to 256k, there is no model one holds and the other does not. Both leave 23 GB to the GPU. So the choice between them is speed, price and power, not what they can hold.
The GeForce RTX 4090, 24GB is also head to head with another card: RTX PRO 6000 Blackwell, 96GB · GeForce RTX 5090, 32GB · Radeon AI PRO R9700, 32GB · GeForce RTX 4080, 16GB · GeForce RTX 3060, 12GB.
The GeForce RTX 3090, 24GB is also head to head with another card: RTX PRO 6000 Blackwell, 96GB · GeForce RTX 5090, 32GB · Radeon AI PRO R9700, 32GB · GeForce RTX 4080, 16GB · GeForce RTX 3060, 12GB.
The assumptions behind both columns
Both columns use the same usage: 500k tokens a day at 15:1 input to output, 32k of context, $0.17 per kWh, and today's API prices held flat. Speeds marked estimated are worked out from memory bandwidth rather than measured, and pay-back scales with them. Both are priced as the card alone, so neither figure includes the PC to put it in. All seven cards here are ranked by what each one holds. Change any of it in the calculator.
More head to head: everything the NVIDIA GeForce RTX 4090, 24GB runs · everything the NVIDIA GeForce RTX 3090, 24GB runs · every other match-up · the quickest pay-back at each level of use · every model against the frontier