This tiny PSU makes even small-form factor units appear massive

This PSU is absolutely tiny. You could actually run a gaming desktop off this miniscule power supply; it comes with all the cables and connectors required to boot a regular motherboard, CPU, GPU, and SATA drive in a form factor not much bigger than an iPhone.

The HDPlex 250W GaN ATX PSU is just 170 x 50 x 25mm in size, and is a completely passive unit—no doubt why it popped up on our friends at FanlessTech's radar. That's sure to be the key to its compact size: there's no 120/80mm fan to force a more square shape or take up precious room.

HDPlex call it "the world's smallest ATX PSU" though I'm not sure what makes it an ATX PSU rather than something else entirely. It offers many of the features you'd expect from a larger ATX PSU, including a few key ones to make sure it doesn't go boom (UVP, OVP, SCP, OPP, OTP).

You're not going to build the most powerful PC with one of these PSUs inside it. With a max output of 250W for a single unit, you'd be hard pressed to actually build a gaming PC with a discrete GPU that wouldn't push it over the limit. It does have a trick up its sleeve to make it that much more worthwhile, however. It is possible to combine two of these PSUs for greater power delivery, up to 500W. That's still some ways off many of the best PSUs for PC, but high-end GPU demands really are extreme nowadays Lower-end GPUs, like the 130W RTX 3050, demand much less power.

Now you could build a decent gaming PC with the 500W power budget provided by two of these PSUs. They're so small that two of them wouldn't take up a massive amount of space, either. Perhaps it defeats the purpose a little, as finding a case to fit their strange elongated shape might be a hassle with a single unit, let alone two, but I'm sure some passive PC builders are already eyeing them up for their next projects. It will definitely fit inside HDPlex's Fanless PC Chassis, anyways.

The PSU isn't rated with the usual 80 Plus specification we're used to seeing, but it is hella efficient. It's reportedly able to achieve 94% efficiency at full load, which puts it right up there with 80 Plus Titanium PSUs.

That efficiency will be extra important for a passive design such as this: greater efficiency means less energy wasted as heat, and less heat means less need for heat dissipation. All of which makes for a more compact PSU.

You can actually see the neat design of the HDPlex above, from the company's product page, and there is a lot of componentry stuffed onto a relatively slim PCB.

The HDPlex 250W costs $145, but it's not available to purchase until sometime in June. You're paying for convenience and its compact shell there, obviously, as otherwise that would be a lot of money for a 250W PSU. More so if you plan to pick up two of them.