PCWorld tests CopprLink as an external GPU interface for RTX 5090

But the solution is expensive and bulky

At present, the strongest option for building an external graphics card is the Oculink interface. Even so, its 64 Gbit/s bandwidth (PCIe 4.0) still is not enough for top-tier 3D cards. The PCWorld team tried out an alternative interface that should have ample headroom even for an RTX 5090.

HighPoint RocketStor 8631D and CopprLink from PCI-SIG

For their setup, the authors used the HighPoint RocketStor 8631D enclosure. It is fitted not with Oculink and not even with Thunderbolt; instead, it relies on CopprLink from PCI-SIG and a dedicated host adapter. Because of its size and cost at this stage, it is not a suitable option for the consumer market, although more practical and cheaper versions may appear later.

PCIe 5.0 x16 bandwidth: up to 64 GB/s bidirectional

The Rocket 7634D provides a PCIe 5.0 x16 link running at up to 64 GB/s in a bidirectional mode. Testing indicates that this is sufficient for any modern graphics card.

RTX 5090 performance results

Naturally, the testing was carried out with an RTX 5090. With this interface in use, performance compared with a standard internal PC connection dropped by only 2.29%, which is effectively negligible.

From a technical standpoint, then, it is an excellent solution. However, the enclosure together with the adapter costs $2,200, which is unlikely to appeal even to RTX 5090 owners.