Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | NVIDIA - GeForce RTX 4090 | AMD - Radeon RX 7900 XT |
|---|---|---|
| CUDA / Stream cores | 16384 | 5376 |
| TDP | 450 W | 315 W |
| Ray tracing cores | 128 | 84 |
| 3DMark Time Spy | 28000 | 18800 |
| VRAM | 24 GB | 20 GB |
| Memory bus | 384 bit | 320 bit |
Between the GeForce RTX 4090 and Radeon RX 7900 XT, the GeForce RTX 4090 comes out ahead in cuda / stream cores / ray tracing cores, while the Radeon RX 7900 XT wins on tdp. Overall, the GeForce RTX 4090 scores 78 and the Radeon RX 7900 XT scores 67.2 on our Mars Score.
Which should you buy?
The GeForce RTX 4090 is the clear pick on raw spec strength, leading by 10.8 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
Pick the GeForce RTX 4090 if you push the hardware — gaming, on-device AI, heavy multitasking — and the extra compute headroom is worth the trade-offs. The biggest gaps in its favor are cuda / stream cores, ray tracing cores, 3dmark time spy, among others. The single most decisive one: CUDA / Stream cores — 204.76% more. 16384 vs 5376.
Pick the Radeon RX 7900 XT if you care most about tdp. Its strongest claims are tdp. The single most decisive one: TDP — 135.00 W less. 315 vs 450.
There are no meaningful ties on the headline specs — every popular-comparison metric has a winner.
Bottom line: the GeForce RTX 4090 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: NVIDIA - GeForce RTX 4090 or AMD - Radeon RX 7900 XT?
NVIDIA - GeForce RTX 4090 leads the current Mars Score by 10.8 points.The more useful decision is the trade-off behind that result: compare vram, cuda / stream cores, boost clock, tdp against the way you will actually use the product.
Choose NVIDIA - GeForce RTX 4090 if…
NVIDIA - GeForce RTX 4090 has the measurable edge on cuda cores, ray tracing cores, timespy score.
Choose AMD - Radeon RX 7900 XT if…
AMD - Radeon RX 7900 XT has the measurable edge on tdp w.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why NVIDIA - GeForce RTX 4090 wins
- ▲CUDA / Stream cores — 204.76% more. 16384 vs 5376.
- ▲Ray tracing cores — 52.38% more. 128 vs 84.
- ▲3DMark Time Spy — 48.94% more. 28000 vs 18800.
- ▲VRAM — 20.00% more. 24 GB vs 20 GB.
- ▲Memory bus — 20.00% more. 384 bit vs 320 bit.
- ▲Boost clock — 5.00% more. 2520 MHz vs 2400 MHz.
- ▲Has DLSS.
Why AMD - Radeon RX 7900 XT wins
- ▲TDP — 135.00 W less. 315 vs 450.
Spec comparison
Core
| Spec | NVIDIA - GeForce RTX 4090 | AMD - Radeon RX 7900 XT |
|---|---|---|
| Chipset | AD102 | Navi 31 |
| Base clockⓘ | 2235 MHzlead | 1500 MHz |
| Boost clockⓘ | 2520 MHzlead | 2400 MHz |
| CUDA / Stream coresⓘ | 16384lead | 5376 |
| Ray tracing coresⓘ | 128lead | 84 |
Memory
| Spec | NVIDIA - GeForce RTX 4090 | AMD - Radeon RX 7900 XT |
|---|---|---|
| VRAMⓘ | 24 GBlead | 20 GB |
| VRAM typeⓘ | GDDR6Xlead | GDDR6 |
| Memory busⓘ | 384 bitlead | 320 bit |
Power & Form
| Spec | NVIDIA - GeForce RTX 4090 | AMD - Radeon RX 7900 XT |
|---|---|---|
| TDPⓘ | 450 W | 315 Wlead |
| Recommended PSUⓘ | 850 W | 750 Wlead |
| Length | 304 mm | 276 mmlead |
| Slot size | 3-slot | 2.5-slot |
Benchmarks
| Spec | NVIDIA - GeForce RTX 4090 | AMD - Radeon RX 7900 XT |
|---|---|---|
| 3DMark Time Spyⓘ | 28000lead | 18800 |
| DLSSⓘ | truelead | false |
| FSRⓘ | false | truelead |
Frequently asked
Which has more VRAM, GeForce RTX 4090 or Radeon RX 7900 XT?+
GeForce RTX 4090 ships with 24GB GDDR6X vs 20GB.
Which scores higher in 3DMark Time Spy, GeForce RTX 4090 or Radeon RX 7900 XT?+
GeForce RTX 4090 scores 28000 vs 18800.
Which draws less power, GeForce RTX 4090 or Radeon RX 7900 XT?+
Radeon RX 7900 XT draws 315W TDP vs 450W.