CopprLink triumphs over OCuLink in new RTX 5090 eGPU test

PCI-SIG unveiled CopprLink back in May 2024, and so far, it has not seen as wide adoption as OCuLink or USB4. However, it brings more performance to the table. As the consortium highlighted during the unveiling, the new interface can currently support data rates of up to 64 GT/s.

In comparison, OCuLink 4.0 can reach 16 GT/s per lane. This difference should lead to much better eGPU performance with the CopprLink, and PCWorld has just proved it.

PCWorld has put a CopprLink setup to the test with a desktop Nvidia RTX 5090. This setup relied on HighPoint's RocketStor 8631D, which relies on CopprLink cabling. However, unlike a regular eGPU setup, this one can't directly connect to a desktop, laptop, or gaming handheld.

Instead, the host PC requires a dedicated high-performance adapter, offering a PCIe Gen 5 x16 connection. This alone pretty much explains why CopprLink didn't become as popular as OCuLink in the consumer eGPU segment yet (Bosgame 7600M XT eGPU curr. $689.99 on Amazon).

Moving to the benchmarks done by PCWorld, they point to an average of around 2.29% performance drop over native. In comparison, a test done by Golden Pig Upgrade in 2024 highlighted that with OCuLink, the performance drop can be close to 23%.

Now, while that performance difference makes the CopprLink the clear winner, it's worth noting that both the eGPU enclosure and adapter reside in the premium range. Specifically, the RocketStor 8631D dock costs $1,299, while the adapter card goes for $999. Check out PCWorld's video attached below to learn more about the test.