NVIDIA's flagship GeForce RTX 4090 graphics card has been used as an external GPU through an OCulink connector and benchmarked in 3DMark benchmarks with some surprising results. Check them out:


RTX 4090 used as an external GPU over OCulink (source: Golden Pig Upgrade)
Chinese reviewer "Golden Pig Upgrade" has used both NVIDIA's flagship GeForce RTX 4090 and new GeForce RTX 4070 Ti SUPER graphics card with an OCulink connector, used as an external desktop GPU and into a new laptop powered by Intel's new Core Ultra 5 125H processor. We get to see some bottlenecks in action, which is very interesting to see.
Starting with the GeForce RTX 4090 connected through OCulink in the pictures above, we have 3DMark TimeSpy scores of 36487 points when used in desktop form, while in the graphics dock and internal display used, we have 28230 points (a larger 22.6% reduction in performance, while in the graphics dock and the RTX 4090 using the external display scoring 30429 points which is a 16.6% performance loss over OCulink.


RTX 4090 used as an external GPU over OCulink (source: Golden Pig Upgrade)
In a less CPU-bound situation, running 3DMark TimeSpy Extreme in desktop GPU form with a score of 19930 points. Moving into the graphics dock and internal display provides 18902 points, which is a 5.2% performance loss while using an external display pushes 19925 points (no performance loss).
- Read more: OneXGPU is the world's first eGPU with M.2 SSD storage, OCulink connectivity
- Read more: OneXGPU external GPU specs: Radeon RX 7600M XT 120W, OCulink, USB4, M.2 slot for $599
Golden Pig Upgrade reported the findings as:
Connected to GeForce RTX 4090:
Time Spy graphics split
- Desktop: 36487
- Graphics dock (inner screen): 28230
- Performance loss: 22.6%
- Graphics card dock (external screen): 30429
- Performance loss: 16.6%
Time Spy Extreme graphics
- Desktop: 19930
- Graphics card dock (internal screen): 18902
- Performance loss: 5.2%
- Graphics card dock (external screen): 19925
- Performance Loss: 0
Connected to GeForce RTX 4070 Ti SUPER:
Time Spy graphics split
- Desktop: 24613
- Graphics dock (inner screen): 22199
- Performance loss: 9.8%

RTX 4070 Ti SUPER used as an external GPU over OCulink (source: Golden Pig Upgrade)
Next up, NVIDIA's new GeForce RTX 4070 Ti SUPER graphics card over the OCulink connector features 24613 points in desktop form while the graphics dock and internal display drop to 22199 points, which is a 9.8% performance loss over OCUlink.
It's interesting to see the GeForce RTX 4090 used as an external graphics card, which in the 4K resolution run of 3DMark -- TimeSpy Extreme -- has almost no performance decrease using an external display. That's an awesome GPU for gamers who need an external graphics card connected to their laptop, but they'll need OCulink connectivity for this.
OCulink is a new connector that spawned in 2023 for laptops, after being in the server world for many years. Thunderbolt development has been slow, which is why we've got OCulink, something that is great in the meantime, before Thunderbolt 5 arrives in 2025.