...a continuation of a build log.
Here is how I set up the Sapphire Pulse RX 570 Mini ITX into this black monolith. As mentioned before, the current discreet video card market seems to be full of intentionally factory-overclocked supersized cards, or very weak single slot SFF solutions. I aimed at something reasonably performant for this build, and since I intend to run Linux most of the time, something from AMD. Sapphire RX570 ITX seemed like the only reasonable choice, provided it can be under-volted & under-clocked. That was until I saw a first reviews of RX 560 cards, but screw it, I already made a purchase, and modding VBIOS seems like a fun
So, here it is, Sapphire Pulse RX 570 Mini ITX, in its virgin state:
Before I even consider which graphics card to use for this build, I got miself the one and only GPU heatsink solution, an excellent HDPlex H5 GPU set. This thing deserves a build log or review of its own, but I'll just focus on how I paired it with Sapphire card & Streacom DB4 case.
This heavy copper pad, and trust me, this sole piece seems heavier than the whole Sapphire card stock cooling solution put together, comes riddled with quite flexible set of holes. It also comes included with relatively flexible (and that comes important later on) heat-pipes as well as solid quality thermal paste.
Luckily, the copper pad holes were of good match, it fits pretty well. With the copper pad on, the part of the card around GPU die become so heavy, that it felt like the PCB would crack if the card was not held in a correct manner. Also, the screws for tightening the copper to the PCB are somewhat short, so the process of attaching it to the PCB brings in the risk of damaging the GPU die or PCB. Where goes the risk, so does the thrill, but be warned when attempting such endeavours by yourself, patience is essential... Unfortunately, the copper pad does not cover the 6 out of 8 DDR5 ICs in an optimal manner, it touches approximately 20% of the surface of those thermal pads.
Since the Sapphire Mini was the last component that I got, I added it to the rest of the system after setting up the CPU cooling solution. The card PCB format is perhaps a bit too tall for smaller Mini ITX cases, as it goes 11mm above the upper edge of PCIe slot metal bracket, and is impossible to be placed in DB4 once the motherboard is fixed inside. Fortunately, DB4 proved very versatile, its whole bottom cover, together with horizontal piece of an aluminium frame can easily be removed with a proper hexagon driver (of a smaller size than the one included).
So finally, the card popped in to the slot, ready to be exposed to even more torture...
But what with that PCIe power connector? Expectedly, due to the card PCB height, normal connector would just not fit in. Hence, I had to make this hackjob connector from some cheap 12V PCIe 6-pin extension cable, in a way that the wires are sticking out sideways from it. Apparently, ready made L-profile PCIe power cables are available for purchase at some places, but not in here.
Smooth job so far, ha? Time for some real challenge, the pipe-work. Since the heat-pipes included with HDPlex were never meant to be used in anything else than HDPlex H5 case, they would need to be shaped into obedience towards Streacom DB4. First, the dull angled bends on the four shorter pipes had to be straightened, and then then bent into an U shape.
Bending heat-pipes by bare hands is never going to produce a perfect result, but armed with patience and some improvised helping tools (a wheel from an old cabinet) a satisfactory result was achieved. The pipes included with HDPlex GPU set are of softer type, they bend relatively easy, meaning its also easy to screw them up in the process. For the remaining four longer pipes, just one of them had to be straightened, so the result of that half of a pipe-work looks much cleaner.
Ultimately, after greasing up the copper pad with thermal paste, and adding up some mini heatsinks to the DDR5 and power ICs...
...the copper pipe monster ended up attached to the poor Sapphire Mini.
At this point an aluminium sink from HDPlex GPU set was intentionally left somewhat loose, so that the Streacom aluminium pads & attached heat pipes can be precisely adjusted in order to have heat pipes touching the chassis aluminium side plates in an optimal manner. After finding the optimal position & tightening the sink to the card, the time had come to grease up the side of the pipes meant to dissipate the heat to the chassis. When the chassis plates got back in place, the shorter set of pipes fit in pretty tight, putting some pressure on the card itself, but the the longer set of pipes provided some resistance to withstand that pressure. Not optimal, but acceptable, provided that the chassis plates are mounted back in a correct order.
OK, so we have the card in place, heat-sink set mounted, chassis tightly closed, but what's with that PCIe power connector? It turned out it barely fits in, could be accessed only when the chassis plate on its side is removed, and there is just about 1mm of space between the connector plastic cap and the chassis plate.
After all the torture done to the Sapphire Mini, I was pleasantly surprised that it actually worked. This being my first attempt to cool a GPU passively, I've baked a very power-conservative custom VBIOS for the card, one limiting the GPU power usage to just 85W (vs default 120W), just for the initial round of burn tests. After an hour of Furmark, GPU temp barely reached 71C. The heat dissipates to the chassis pretty fast, and it does spread well over the aluminium plate surface. The plate attached to the longer set of pipes is expectedly more efficient, it gets warmer a bit quicker than the plate attached to the shorter set, but the other one catches up soon enough.
That's it for now. In the meantime I'll spend some more time searching for VBIOS mod efficiency sweet spot for this build. I don't expect the GPU to be able to go even close to its default 120W GPU (plus an overhead for DDR5 and the rest of the logic), but I'd be happy if I could squeeze 75% of its nominal performance for this build... (an advanced advices on how to optimize VBIOS are more than welcome).
