A Compact Upgradeable Mini EGPU made out of a thunderbolt SSD enclosure and some wood

Introduction

External GPUs (eGPUs) have long been a popular solution for those wanting desktop-class graphics on a laptop. However, commercial eGPU enclosures tend to be bulky, overpriced, and often come with non-upgradeable GPUs. Even so-called “mini eGPUs” fail to maximize performance in a truly compact form factor.

If you’re looking for an affordable, high-performance alternative, you can build your own modular mini eGPU using easily available components—potentially for half the price of commercial options like the GPD G1. In this guide, I’ll walk you through my DIY approach to building a fully functional mini eGPU, detailing the parts, assembly, and setup process.

Components for the Build

For this project, I used an NVIDIA GT 1030 for demonstration purposes, but you can swap it out for any low-profile GPU, such as the Gigabyte or ASUS 4060 LP cards. If you’re considering higher-end GPUs, keep in mind that external PCIe protocols like Thunderbolt and OCuLink are bandwidth-limited. A 4060-class card strikes the right balance between performance and efficiency for mobile computing.

Core Components:

• GPU: Low-profile graphics card (GT 1030, 4060 LP, etc.)
• NVMe-to-PCIe x16 converter: Converts the NVMe connection to a standard PCIe x16 slot
• NVMe-to-Thunderbolt or OCuLink adapter: Bridges the connection between the GPU and laptop
• Power Supply: 12V adapter (or a Pico PSU if your adapter requires 5V and 12V)
• Cooling & Indicators:
  • 12V exhaust fan
  • LED light switch as a power indicator
  • Metal DC power port with a cover

A compact custom enclosure can be designed later to make the setup even smaller and more aesthetically appealing.

Step-by-Step Build Process

1. Preparing the GPU and PCIe Converter

• Remove the GPU’s IO bracket.
• Attach the PCIe-to-NVMe converter to the graphics card.

2. Setting Up the Thunderbolt Adapter

• Install a small riser for spacing.
• Attach the NVMe-to-Thunderbolt adapter to the riser.
• Secure the GPU assembly to the Thunderbolt adapter using double-sided and thermal-resistant tape.

3. Powering the eGPU

• Prep the female connector cable, ensuring the 5V leads are sealed off.
• Prepare the 12V connection by testing voltage before attachment.
• Referencing the power switch wiring diagram, connect:
  • Power adapter
  • DC female port
  • 12V exhaust fan
• Attach the power cable from the PCIe converter to ensure a stable 12V supply.
• Perform a quick test to confirm power delivery.

4. Building the Enclosure

• Cut wooden panels and drill necessary holes.
• Mount all components securely inside.
• Install the DC power port before finalizing the connections.
• Reassemble and tidy up wiring.

After several adjustments and some frustrating retries, the build finally comes together, ready for testing.

Installing Drivers and Testing Performance

Since eGPUs aren’t typically hot-swappable, follow these steps for driver installation:

1. Power down your laptop before connecting the eGPU.
2. Check the Device Manager to confirm that the GPU is detected.
3. Install necessary GPU drivers (NVIDIA, AMD, etc.).
4. Connect an external monitor to verify output.
5. Run performance tests, such as MSI Kombustor, to confirm stability.

For an additional test, I played high-definition videos and found that video rendering performance was solid—proving that the setup works as expected.

Conclusion

If you’re looking to avoid the high costs and limitations of commercial eGPUs, this DIY solution is an excellent alternative. With some creativity, you can design a more compact and efficient custom enclosure, further enhancing portability.

For my next project, I’ll be building an OCuLink-based eGPU setup with a similar approach—so stay tuned for that! If you end up building your own mini eGPU, feel free to share your results.

Thanks for reading, and happy building!