RTX 4090 Mobile vs R9 M390X
Head-to-head specifications
| Metric | RTX 4090 Mobile | R9 M390X | Difference |
|---|---|---|---|
| 3DMark Time Spy | 28,076 | 1,435 | +1,856.5% |
| Avg FPS @ 1080p | 207 | 29 | +613.8% |
| Avg FPS @ 1440p | 132 | 16 | +725.0% |
| Avg FPS @ 4K | 75 | 8 | +837.5% |
| FP32 compute (TFLOPS) | 70.2 | 4.1 | +1,612.0% |
| VRAM | 16 GB GDDR6X | 4 GB GDDR5 | — |
| Memory bandwidth (GB/s) | 1,008 | 160 | +530.0% |
| TDP (W) | 270 | 125 | — |
- RTX 4090 Mobile averages 132 fps at 1440p versus 16 fps — about 725% faster.
- R9 M390X draws less power (125W vs 270W).
Verdict: RTX 4090 Mobile or R9 M390X?
RTX 4090 Mobile advantages
- 1440p gaming (+88%)
- 4K gaming (+89%)
- Synthetic benchmark performance (+95%)
- Video memory (+75%)
- Memory bandwidth (+84%)
R9 M390X advantages
- Power efficiency (+54%)
Which should you choose?
- Choose the RTX 4090 Mobile if you game at 1440p.
- Choose the R9 M390X if you want lower power draw, heat and noise.
- Choose the RTX 4090 Mobile if you game at 4K or drive a high-resolution display.
RTX 4090 Mobile vs R9 M390X: which should you choose?
RTX 4090 Mobile — NVIDIA laptop graphics card (2022, Ada Lovelace) with 16 GB of GDDR6X, averaging 132 fps at 1440p.
R9 M390X — AMD desktop graphics card (2015, GCN 1.0) with 4 GB of GDDR5, averaging 16 fps at 1440p.
RTX 4090 Mobile vs R9 M390X: RTX 4090 Mobile is faster for gaming. RTX 4090 Mobile averages 132 fps at 1440p versus 16 fps — about 725% faster. R9 M390X draws less power (125W vs 270W).
1080p, 1440p and 4K
At 1440p — the most common enthusiast resolution — the RTX 4090 Mobile averages 132 fps against 16. At 4K (75 vs 8 fps) VRAM (16GB vs 4GB) and memory bandwidth matter more.
Power and value
Board power is 270 W versus 125 W, which affects PSU headroom, case cooling and noise.
The verdict
Both are credible choices in the graphics card comparison space; the specification table above lays out every metric so you can weigh the trade-offs that matter to you. Pick the one whose strengths line up with how you will actually use it.
Frequently asked questions
Is the RTX 4090 Mobile better than the R9 M390X?
RTX 4090 Mobile is the clearly stronger overall choice, winning most of the dimensions that matter. RTX 4090 Mobile averages 132 fps at 1440p versus 16 fps — about 725% faster.
What is the main difference between the RTX 4090 Mobile and the R9 M390X?
RTX 4090 Mobile averages 132 fps at 1440p versus 16 fps — about 725% faster. R9 M390X draws less power (125W vs 270W).
Which should I choose?
Choose the RTX 4090 Mobile if you game at 1440p. Choose the R9 M390X if you want lower power draw, heat and noise.
Methodology
Graphics cards are compared on 3DMark Time Spy scores, average gaming frame rates at 1080p/1440p/4K, FP32 compute throughput, VRAM capacity and type, memory bandwidth, board power (TDP) and launch MSRP — plus AI workload throughput (Stable Diffusion iterations/s and local LLM tokens/s) where measured. Vintage and server GPUs without modern benchmark results are compared on specifications only, clearly labelled. Frame rates are averages across a game suite at high settings; specific titles vary.