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| The TA255 is limited by its lack of PCIe 5.0 support. Pictured: the mini PC connected to an eGPU dock. |
The mini PC market just got a whole lot more interesting. A relatively under-the-radar brand called TOPC has launched a new AMD-powered tiny desktop in China, and it’s turning heads for one very specific reason: an MCIO interface designed to connect an external GPU (eGPU). While we’ve seen OCuLink ports become the standard for powerful eGPU setups on mini PCs and handhelds, TOPC is skipping straight to something faster – and potentially much more future-proof.
If you’ve been following the world of compact computing, you know that OCuLink (PCIe 4.0 x4) has been the go-to solution for folks who want desktop-level graphics without sacrificing portability. It delivers a solid 64Gbps bandwidth. But TOPC’s new TA255 mini PC comes equipped with an MCIO PCIe 4.0 x8 interface, pushing that theoretical bandwidth all the way up to 128Gbps. That’s double the bandwidth of standard OCuLink, which should translate to noticeably less performance drop when you hook up a beefy external graphics card.
For context, GPD teased something similar with its upcoming “Box” mini PC featuring a PCIe 5.0 x8 MCIO port – but that product isn’t out yet. TOPC beat them to market, at least in China, albeit with a PCIe 4.0 implementation. Still, for anyone who’s been frustrated by the bottleneck of OCuLink on devices like the GPD Win Max 2 or Minisforum mini PCs, this feels like a meaningful leap forward.
Under the Hood: Ryzen 7 255 with Radeon 780M
The TOPC TA255 is powered by the AMD Ryzen 7 H 255, a refreshed processor from the Hawk Point lineup. It’s not the latest Strix Point chip, but it’s no slouch either. The integrated Radeon 780M iGPU remains a capable little beast – you can still run many modern games at 1080p with medium-to-low settings smoothly. In fact, it’s the same iGPU found in popular mini PCs like the Geekom A7 Max (currently around $639 on Amazon).
But here’s the kicker: you’re not buying this machine for its iGPU. You’re buying it for what you can plug into that MCIO port. And TOPC has been upfront about a limitation – the Ryzen 7 H 255 doesn’t support PCIe 5.0. So while the MCIO connector itself is physically capable of higher speeds, the CPU holds it back to PCIe 4.0 speeds. The company has hinted that an upgraded model with a PCIe 5.0-ready CPU could be on the horizon. For now, though, 128Gbps of PCIe 4.0 bandwidth is still a massive improvement over the 64Gbps you get from OCuLink 4.0.
Real-World Performance: What the Benchmarks Say
Early testing from Chinese reviewers (including the Bilibili channel “开源姬开源宇宙显卡坞”) shows promising results. In 3DMark’s PCI Express feature test, the MCIO x8 interface on the TOPC TA255 delivered significantly higher throughput compared to a standard OCuLink x4 setup. More importantly, real game benchmarks showed smaller performance gaps between the eGPU setup and a native desktop PCIe x16 connection.
We’ve embedded a link to one of those benchmark videos below – the numbers speak for themselves. In titles that are bandwidth-sensitive, the MCIO port pulls ahead by a noticeable margin. It’s not quite parity with a full-fat desktop slot, but it’s closer than we’ve seen from any OCuLink mini PC to date.
- Watch the comparison: OCuLink x4 vs MCIO x8 game benchmarks on Bilibili
Port Selection: Surprisingly Generous
Beyond that headline-grabbing MCIO port, the TOPC TA255 doesn’t skimp on connectivity. Here’s the full list:
- 3x 5Gbps USB Type-A
- 1x USB4 (40Gbps, also supports DisplayPort alt mode and eGPUs via Thunderbolt, but why would you when you have MCIO?)
- 2x 2.5G Ethernet ports – perfect for home lab or router use
- 1x HDMI 2.1
- 1x DisplayPort 2.1
- 1x USB 2.0 Type-A (for keyboard/mouse)
- 1x 3.5mm audio jack
Wireless connectivity is covered by WiFi 6E and Bluetooth 5.3. The system also has two M.2 slots for SSDs, and TOPC pairs the Ryzen chip with up to 24GB of LPDDR5 RAM – soldered, most likely, so choose your configuration wisely.
Pricing and Availability (China Only, For Now)
In its home market, TOPC is offering the TA255 in two barebones-ish configurations – note that neither comes with storage:
- 16GB RAM: CNY 2,699 (approx. $395)
- 24GB RAM: CNY 2,999 (approx. $438)
You’ll need to supply your own NVMe SSD(s) and, of course, an eGPU dock and graphics card to take advantage of that MCIO port. The company hasn’t announced global availability yet, so international buyers will likely need to rely on importers or wait for an official worldwide launch. Given the niche appeal of an MCIO-equipped mini PC, it wouldn’t be surprising to see it pop up on AliExpress or Indiegogo soon.
Is MCIO the Future for eGPU Setups?
For years, eGPU enthusiasts have been stuck with Thunderbolt (which adds latency and overhead) or OCuLink (faster, but still limited to x4 lanes). MCIO – which stands for “Multi-Channel Input/Output” – is a connector type commonly found on server and enterprise gear, but TOPC and GPD are pioneering its use in consumer mini PCs. The x8 lane width is a huge deal, even at PCIe 4.0 speeds.
The obvious next step is PCIe 5.0 x8 MCIO, which would deliver a staggering 256Gbps of bandwidth – more than enough to fully saturate even an RTX 4090. But we’re not there yet. For now, the TOPC TA255 offers the best eGPU bandwidth you can get in a sub-$500 mini PC, assuming you’re willing to DIY the storage and the graphics solution.
Bottom Line
TOPC’s TA255 isn’t for everyone. If you just want a tiny desktop for office work, media streaming, or light gaming on its own – the Radeon 780M is already fine – you might be better off with a more widely available option like the Geekom A7 Max. But if you’re a tinkerer, a home lab enthusiast, or someone who wants to turn a mini PC into a dockable powerhouse with an external GPU, this little box is seriously compelling.
The MCIO interface is a genuine differentiator, and TOPC deserves credit for shipping it first. Let’s hope a global launch follows – and that a PCIe 5.0 version isn’t far behind.
For more technical details, check out the original ITHome article (machine translated) here.
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| The MCIO port of the mini with a connector |
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| OCuLink x4 vs MCIO x8 game benchmark comparsion with the mini PC |
