Exploring Thunderbolt 3 eGFX Performance, Feat. PowerColor's Gaming Station & Radeon RX Vega 56 Nano

Power Consumption and Thermal Characteristics

The power consumption of the PowerColor Gaming Station (with the Radeon RX Vega 56 Nano installed) was recorded while processing the Furmark stress test using the Intel NUC8i7BEH (Bean Canyon NUC) as the host. We noted that the eGFX enclosure and GPU together idled at around 19 - 30W.

At the beginning of the stress sequence, the at-wall power starts off at around 250W and steadily climbs to around 260W within 3 to 4 minutes. At that point, we see the GPU core temperature approaching 100C, and the unit slows itself down to maintain a temperature around 95C. We see the at-wall power consumption oscillating between 210W to 245W for the next hour (duration of the test).

A Note on Compatibility

It must be kept in mind that eGPUs are not compatible every Thuderbolt 3 host systems; there are some steps that systems need to take to enable this kind of functionality. For example, our Skylake DAS testbed got external graphics functionality for the Thunderbolt 3 port in a post-launch BIOS version. Unfortunately, no amount of playing around with the relevant BIOS options and attempting Thunderbolt 3 firmware upgrades could enable support for external GPUs in the Thunderbolt 3 software.

The eGFX enclosure can still be connected to the host, and all the peripheral ports work. It is just that the eGPU refuses to become active.

Adventurous users have apparently discovered some workarounds for this problem, but we didn't test that out. In the worst case, it is possible that your Thunderbolt 3 system might not support eGPUs at all. There is also a chance that a particular eGFX enclosure might not be a simple plug and play solution. Thankfully, eGFX enclosure vendors do maintain a list of systems that are guaranteed to work with their enclosure. The growth in popularity of Thunderbolt 3 also means that we have a user community of considerable size to fall back upon for usage guidelines and recommendations.