Introduction:

For a while now, I was looking to put together the cheapest possible mPCIe solution for my old NUC to be able to output 4K at 60Hz. This is for desktop use only, not gaming, so about the only required criteria is being extremely cheap, and having a DisplayPort 1.2 output.

Figured I'd share my findings, as I figure this problem is not purely something I dreamed up, and people may be interested in driving a 4K monitor off an old system to gain more screen real-estate, while not spending much money.

The Solution:

This is applicable to all older systems using mPCIe or Expresscard eGPU ports and DisplayPort-connected 4K monitors.

This is based on the Dell OEM Radeon HD7570 1GB GDDR5 card. If you look on ebay, you will see a large amount of them being sold for around 20$. Mine was 16$ with free shipping. What makes this card attractive are four reasons:

It is very cheap, and it looks like there are a lot of them. I guess a lot of OEM systems that sold with these cards are getting retired and computer refurbishers and recyclers have a lot of them on hand. It has two video outputs, one DVI-I, and one DisplayPort 1.2. It is the second one which makes it 4K60Hz capable. The DVI-I supports up to 2560x1600, so this can actually output to a pair of high resolution panels at once. This is a nice upgrade for systems that only have VGA or HDMI outputs (limited to 2048x1536 and typically 1920x1200 on older systems). It is very small, at half-length and low-profile height. Its power consumption is low, which means a small 60W power brick can power it up reliably, and it consumes very, very little power when near-idling on the desktop.

Side note: You can run older games on this (or more modern games at low settings), but this is definitely not a gaming card (for comparison, it is about 60-70% of the performance of the Vega 8 graphics in the Ryzen 2200G, and a bit faster than the HD7570 GDDR3 version. Note that only the Dell one seems to be GDDR5 based, with other varieties running GDDR3).

Windows 10 drivers exist, so this works with a modern OS.

Overall cost of the solution (for mPCIe) is a bit under 40$. For Expresscard, you'll run in at a bit under 70$ due to the more expensive GDC Beast adapter. For mPCIe, here is the parts list:

Dell OEM HD7570 1GB GDDR5 - 20$ (or even less). PCIE164P-N03 mPCIe to PCIe Adapter (barrel plug version) - 7$. 60W power brick with a 2.5x5.5mm barrel plug - 10-12$ (example). You can find quite a few 12V power bricks at Goodwill's electronics section, so give that a shot and you can probably pick one up for even cheaper (like 3-5$) while re-using older junk that would otherwise likely end up in a landfill at some point. I actually used the stock AKiTiO Thunder2 60W power brick that I had laying around, so I didn't even need to buy one.

Setup:

System: Intel NUC33217CK.

Operating System: Windows 10 Professional (64-bit).

Display: Dell P2715Q via DisplayPort.

Power supplies: AKiTiO Thunder2 60W AC/DC brick (12V, 5A) for the eGPU, FSP 65W (19V, 3.42A) for the NUC.

This was plug-and-play. The NUC booted with the eGPU used as its main graphics adapter. Windows 10 was installed, automatically updated the HD7570 driver (and Catalyst software) suite, and set the resolution to 3840x2160 at 60Hz.

I even overclocked the HD7570 to make sure the 60W adapter is truly enough, going from 650Mhz to 750Mhz on the core, and from 800Mhz to 950Mhz on the memory. The rather pitiful benchmark results (Unigine Valley) rose by 12% as a result.

System is rock stable.

A few pictures: