I decided to try something unconventional: attaching an eGPU to the system bus of a budget GMKTec G3 Plus mini PC (compensated affiliate link), curious to see if I could push the limits of what these sub $200 PCs are designed for.
You can see if it works in my latest video.
The G3 Plus lacks the typical external graphics connections like USB4 or Thunderbolt. Instead, I used a workaround — an NVMe to Oculink adapter (affiliate link)—to see if this approach could effectively attach the eGPU to the system bus.
The setup process was straightforward. The G3Plus has two storage slots, one for its included NVME system drive, and a second slot for M.2 SATA disks. I imaged the existing storage drive onto an M.2 SATA drive to free up the NVMe slot, then installed the OCuLink adapter. The external GPU, a GMKTec AD-GP1 has an AMD RX 7600M XT, along with Oculink and USB 4 / Thunderbolt connection options.
Other eGPUs can work too if you get an Oculink PCIe slot adapter like I demoed in this video a few weeks ago. Many of the Oculink NVME kits come with the PCIe adapter. The cool thing about this is that you can interface just about any PCIe card with the PC.
Installation was simple, with the Oculink adapter inserting just like any NVME drive would. The G3 Plus’ slots are accessible on the top of the PC making it very easy for all of this to work.
It’s always a little nerve wracking when the “moment of truth” arrives. To my surprise the system immediately recognized the GPU right at boot and Windows 11 loaded without issue. Installing AMD’s Adrenalin drivers confirmed the GPU was fully detected, and from there, it was time to see how well it performed.
Cyberpunk 2077 was the first test, running at 1080p with ray tracing set to low. The system delivered frame rates in the range of 45 to 50 frames per second, but the CPU quickly became the bottleneck. The GPU utilization never exceeded 62%, demonstrating the limitations of pairing higher-end graphics hardware with a budget processor. Disabling ray tracing barely improved performance.
Red Dead Redemption 2 told a similar story. At 1080p on the lowest settings, frame rates fluctuated between 30 and 45 fps, depending on the complexity of the environment. The CPU remained fully maxed out, while the GPU hovered at just 30% utilization. This was a clear example of how throwing a powerful GPU into a low-end system doesn’t always yield massive gains.
Doom Eternal, however, showed a different side of the experiment. Running at 1080p with the lowest settings, the game reached 128 frames per second, dropping to the 90s in more demanding scenes. The GPU was significantly more engaged in this title, reaching 70% utilization. Turning on ray tracing caused a minor performance drop but still delivered a smooth experience, proving that certain games benefit much more from a powerful GPU than others.
Benchmarking with 3DMark’s Time Spy test revealed a significant GPU-driven boost. Without the external GPU, the mini PC scored 450 points. With the eGPU attached, the score jumped to 6,449, a stark difference that reinforced the impact of the external GPU—when the workload allowed it.
Beyond gaming, I tested an AI large language model with Ollama to see how well the setup could handle AI-based tasks. Running an 8-billion-parameter model, the GPU took full control, rapidly generating text while utilizing its compute power and 8GB of video memory to do it.
While this is not the most practical configuration, the experiment demonstrated the versatility of mini PCs when expanded through OCuLink. Despite some limitations, it was surprising to see how plug-and-play the process turned out to be.
Check out my review of the G3 Plus here.
Disclosure: I purchased the Mini PC with my own funds and GMKTec provided the eGPU to the channel free of charge for my prior review. No other compensation was received and they did not review or approve my content before it was uploaded. All opinions are my own.