Premium Build: Greyscale — building a custom-looped ITX PC that pushes the form factor to its limits
For many, the most daunting part about building a custom looped system is installing a GPU block, and there are a few reasons why. Getting a stock cooler off a graphics card can be quite a convoluted process, you often need to go through a ‘warranty void if damaged’ sticker, and unlike a CPU which has a heatspreader to protect the die, GPUs don’t come with heatspreaders at all.
Now, personally, I really like that GPUs don’t come with heatspreaders – in a custom loop where the CPU is not delidded, a GPU always runs about 20 degrees cooler than the CPU. That’s a huge temperature difference that’s entirely to blame on the IHS (integrated heat-spreader.) However, it does mean you have to be careful removing the cooler, because you do not want to accidentally crack the GPU die.
To remove the cooler from MSI’s RTX 5090 Suprim, we begin by removing the backplate, which, as expected, features a warranty void if damaged sticker on one of the screws.
It’s amusing to see modern graphics cards exposed, as their PCBs are comically tiny compared to the full size of the end product with the cooler. I suppose this is why even cheaper GPUs come with backplates nowadays – to mask how small the PCBs are.
Here came the delicate part of the operation. One does not simply pull the PCB upwards from the cooler – doing so would put heavy strain on the GPU die.
In the case of this particular graphics card, this was especially so. The thermal paste was bone-dry and had all but glued the GPU to the heatsink.
To prevent any damage in cases like this, you can rotate the PCB slightly clockwise, then anticlockwise, and repeat the movement until it starts to give way. Once that happens, you can gently pull on the PCB a little while continuing the shimmying motion. After a little while, it’ll come off without using much force.
Now keep in mind, this particular graphics card is a media sample that’s been in rotation between various outlets since the beginning of the RTX 5090’s launch – it’s flown all over the world, been in many PC’s, and although it’s not been taken apart yet by anyone, even the packaging made it clear that this is a GPU that’s been passed around extensively.
You never truly know what these media samples have gone through, so perhaps it’s a good thing it ended up in my shop for servicing at this point in its life.
The same gentle approach applies to the connectors that wire the fans and RGB to the PCB. Whereas most connectors in the rest of a PC build are sized for human hands to be able to undo the clips, the connectors here are much smaller. Now, I could probably pull on them to get them to disconnect – the clips are quite small and would probably be overcome by force. But, this is a loaner card from MSI, and I absolutely did not want to call them to let them know I destroyed one of their precious 5090’s, especially in this GPU market.
With that, the GPU was disassembled successfully.
What’s interesting here is that pictured above are all the parts you need to remove to get to the 5090 Suprim’s PCB. I’ve taken apart quite a handful of GPUs in my time, and of course, there were simpler ones, but for a flagship GPU with a large, intricate cooler, this was actually really quite easy. As long as you take the proper precautions, it’s actually really quick and straightforward – I’ve had GPUs where I had significantly more steps involved in getting the PCB separated from the cooler.
Let’s take a moment to admire this GPU
Even here at Tom’s Hardware, it’s not every day that we get to witness a bare GPU die, especially not from an RTX 5090. Of course, we’re free to do what we want with our own GPUs bought with our own money, but with media samples, we’re often not allowed to tear them apart, even for some GPU reviews.
The RTX 5090 Suprim is really something to behold once undressed and cleaned up. Of course, seeing the spec of 750 mm2 was the first giveaway that this was going to be a big GPU, but seeing it up close, like this… I had to grab a CPU to give a reference point you can relate to.
My father-in-law used to sell lithography machines before he retired, and I showed him this – he was in awe that a single chip could be this big. “No wonder the prices are so high – you can’t fit a whole lot of those on a single wafer.”
Generally speaking, I like to take the “X” approach to applying thermal paste to GPUs, letting the mounting pressure spread it evenly over the die. However, with the size of this GPU, I decided not to take any chances and followed Alphacool’s instructions, using the spatula to ‘plaster’ the paste over the die. I’m not sure if this is really a better approach, but the thermals in testing later were spectacular, especially on a cold loop.
Then, I placed the GPU block on a soft detailing rag so that the acrylic wouldn’t scratch, and applied the thermal pads.
I carefully placed the GPU onto the block, and placed the thicker thermal pads on the rear of the memory modules and the power connector. This is so that these can cool via the backplate.
I then placed the GPU over the edge of my desk so that the I/O bracket would fit, installed the backplate, and secured all the screws, cross-hatching them for even mounting pressure to ensure all were tightened up correctly.
With that, we have a GPU block installed on a 5090. That was surprisingly easy.
Because I wouldn’t be able to get to these later, and because I really didn’t want to forget, I installed the plugs. One of these didn’t go in as deep as the other, though. Fingers crossed that’s not a problem in the future.
With the GPU installed into the system, it confirmed my biggest fears: I did not have space for the Phanteks T30-140’s.
Leaning on the port plugs, the GPU was perfectly level. This here was maybe two mm of breathing space.
With how much the GPU was covering the fans, this was a blockage that even the almighty T30’s wouldn’t be able to overcome. I really wanted to use these fans, but this build was already pushing the limit for cooling capacity, and this here would be asking for problems.
This situation called for Noctua to come save the day, and although the 120mm variant of the NF-A12x25 G2 isn’t out yet in black, the 140mm flavor is, so I bolted over to my local PC parts store and grabbed an Sx2-pp kit.
This gave me 5mm extra breathing space around the edge of the frame, which, although still not a whole lot, would be a lot better than almost no breathing space at all.
