Aostar AG03 eGPU Enclosure Review: A Practical Thunderbolt 5 Upgrade

Introduction

External GPU enclosures have become an increasingly practical way to add desktop-class graphics power to laptops, mini PCs, and handhelds. The Aostar AG03 is the latest iteration in this space, building on its predecessor with Thunderbolt 5 connectivity and a built-in 800W power supply. At $260 on the manufacturer’s website or $270 on Amazon, it positions itself as one of the more affordable options in a category that has historically carried a premium price tag.

The appeal of an eGPU setup is straightforward: you bring your own graphics card, plug it into the enclosure, and connect it to a portable device to get a full desktop experience. The AG03 supports both Oculink and Thunderbolt connections, giving users flexibility depending on what their computer offers. This review covers the design, installation process, performance across different connection standards, and the compatibility considerations that come with this type of setup.

Design and Build Quality

The Aostar AG03 is a chunky piece of hardware, weighing in at just over 1.7 kg or about 3 lb 12 oz. That weight is actually a positive feature. When you place an expensive graphics card on top, the enclosure feels sturdy and stable. The open-air design means the GPU is exposed rather than hidden inside a full enclosure, which some users will appreciate for the visual appeal of seeing the fan spin during use.

The chassis is made of dark metal with a compact footprint that fits comfortably on a desk. On the front panel, you will find the Thunderbolt switch button, which toggles between Oculink and Thunderbolt modes. Next to that is the Oculink port, which is not hot swappable, so you need to power down both the computer and the dock before plugging or unplugging anything. Below that are two Thunderbolt 5 ports, one for connecting to your computer and another that provides up to 27 watts of power output and supports DisplayPort data for connecting to a USB-C monitor.

The back of the unit houses the power cable and the built-in 800W power supply with a small fan. On the opposite side, there are three PCIe ports for the graphics card, and a knob on the front secures the GPU in place. The bottom has hard plastic feet that slightly elevate the dock, and six screws allow access to the power supply if needed. The top features the standard eGPU connector you would find on any motherboard.

Installation Process

Installing a graphics card into the AG03 is a straightforward process. You start by removing the front knob, which will later secure the GPU. On the back, there is a riser bracket included in the box that attaches to the chassis. You want to leave it slightly loose initially because you will need to adjust its height once the graphics card is in place.

From there, you align the graphics card with the PCIe slot and push it into place. There is an ejector tab that should click in fully to ensure a secure connection. After that, you tighten the front knob to hold the card firmly. The riser bracket on the right side helps offset some of the weight from the left, making the whole setup feel more stable than the previous model.

The final step is connecting the PCIe power cables. The enclosure includes three cables, and the number you use depends on your graphics card’s requirements. The cables are not labeled, but the ports are arranged in a row, and using two of them should be sufficient for most mid-range cards. The exposed cables are the least attractive part of the design, but they are mostly hidden depending on how you arrange the setup on your desk.

One notable omission is that the AG03 does not include an Oculink cable in the box. The previous model did, and given that this version is $50 more expensive, it feels like a cost-cutting measure. An Oculink cable costs about $20 to buy separately, so it is not a dealbreaker, but it does mean the enclosure is not a complete all-in-one experience out of the box.

Ports and Connectivity

The AG03 offers three main connection options: Oculink, Thunderbolt 4, and Thunderbolt 5. The Oculink port provides the highest bandwidth, but it requires a full system shutdown before connecting or disconnecting. Thunderbolt connections, on the other hand, are hot swappable, which is a significant convenience for daily use.

The two Thunderbolt 5 ports are a key upgrade over the previous model. One port connects to your computer and supports up to 140 watts of power delivery, which is useful for powering a laptop or handheld through a single cable. The second port provides up to 27 watts of output and supports DisplayPort data, making it possible to connect a USB-C monitor directly to the enclosure.

For users with Thunderbolt 4 devices, the AG03 works without issue. The bandwidth over Thunderbolt 4 measured about 4 GB per second in testing, which is slightly better than the previous AG02 model. The real benefit of Thunderbolt 5 will become apparent as more computers adopt the standard, but for now, the AG03 is future-proofed for that transition.

Performance Testing

Performance testing revealed some interesting results. Using a mini PC with a Ryzen 7 8845HS chip and Radeon 780M integrated graphics as a baseline, the integrated graphics scored 3,386 in the 3DMark Time Spy benchmark. Connecting an RTX 5070 through the AG02 brought that score up to 18,881, a more than fivefold improvement. The AG03 scored slightly better, though the difference was negligible in this particular benchmark.

In-game testing told a different story. With Cyberpunk 2077 at 1440p high settings, the integrated graphics managed 24.39 frames per second on average. The AG02 with the RTX 5070 delivered 97.66 frames per second, while the AG03 pushed that to 120 frames per second. This is a significant jump between the two enclosures, despite using the same GPU, same drivers, and the same Thunderbolt 4 connection.

A similar pattern appeared in Returnal at 1440p medium settings. The integrated graphics averaged 22 frames per second, the AG02 delivered 118, and the AG03 reached 132. The AG03 consistently used more of the GPU’s potential, often capping out at about 99% utilization, while the AG02 hovered around 80%. This suggests the newer enclosure is better at delivering the full performance of the graphics card.

Comparing Oculink and Thunderbolt 4 on a laptop with a Ryzen AI 9 HX370, the bandwidth difference was substantial. Oculink measured about 7.2 Gbits per second in the 3DMark PCI Express feature test, compared to 4.0 Gbits per second over Thunderbolt 4. However, actual game performance was nearly identical between the two connection types. With a mid-range GPU like the RTX 5070, the extra bandwidth of Oculink does not translate into meaningful performance gains because the GPU itself is the limiting factor.

Handheld and Linux Compatibility

One of the more appealing use cases for an eGPU is connecting a gaming handheld to get desktop-class performance. The AG03 website includes a disclaimer that it is not compatible with the ROG Ally X Z2 Extreme, and testing confirmed this. The enclosure would supply power to the handheld, but the system would not detect the connected Nvidia GPU. This is likely due to the specialized GPU drivers used on handhelds.

That said, compatibility is not universally poor. The Legion Go connected and worked out of the box with the AG03, allowing the Nvidia drivers to install and the eGPU to function normally. The key takeaway is that handheld compatibility is hit or miss, depending on the manufacturer and their driver support. If you plan to use an eGPU with a handheld, it is wise to purchase from a retailer with a good return policy in case it does not work with your specific device.

Linux support is another area where expectations need to be managed. Nvidia GPUs generally lack the driver support on Linux that they have on Windows, and the RTX 5070 would not connect at all in testing. An older AMD Radeon RX 6650 XT, however, worked right out of the box when connected via Oculink. It only functioned in desktop mode rather than gaming mode, but it did deliver a meaningful performance boost. In Cyberpunk 2077 at 1440p high settings, the mini PC with integrated graphics averaged 28.7 frames per second, while the same system with the RX 6650 XT reached 61.34 frames per second.

Buying Advice

The Aostar AG03 is best suited for users who already own a graphics card and want to add desktop-class performance to a laptop, mini PC, or compatible handheld. The built-in 800W power supply is a significant advantage, as it eliminates the need to purchase a separate PSU. At $260, it is the cheapest Thunderbolt 5 eGPU enclosure currently available, undercutting competitors like the Razer Core X v2, which costs $350 but requires you to supply your own power supply at an additional cost of around $110.

For those considering the previous AG02 model, the AG03 is the better choice. It costs about $50 more but delivers slightly better performance and adds Thunderbolt 5 connectivity, making it more future-proof. The performance difference was noticeable in real-world gaming tests, with the AG03 consistently using more of the GPU’s potential.

The Razer Core X v2 is a viable alternative if you prefer a full enclosure design, but the total cost is significantly higher once you factor in a power supply. The Minisforum DEG2 offers Oculink support at a similar price to the AG03, but it lacks full Thunderbolt 5 and also requires a separate power supply.

For users who prioritize portability above all else, the Asus ROG XG Mobile is an ultra-compact option with a mobile GPU built in. However, it costs around $2,000, is not upgradeable, and is difficult to recommend for most users given the price and lack of flexibility.

Conclusion

The Aostar AG03 delivers on its promise of an affordable, self-contained eGPU enclosure with modern connectivity. The built-in 800W power supply, Thunderbolt 5 ports, and solid build quality make it a compelling option for anyone looking to extend the life of a portable device with desktop-class graphics. Performance is strong, especially compared to the previous model, and the price undercuts most of the competition.

The main drawbacks are the missing Oculink cable, the exposed PCIe cables, and the inherent compatibility challenges that come with eGPU setups, particularly with handhelds and Linux. These are not dealbreakers for most users, but they are worth keeping in mind. If you have a mid-range or high-end GPU and a compatible laptop or mini PC, the AG03 is one of the best value options available today.