Let me start off by saying that I don’t put a lot of Micro-ATX machines together, and now I remember why; it’s a lot less fun and takes a lot more planning, a lot more time, and can be a lot more frustrating if things don’t go as planned. In general, there has to be a lot more attention paid to cable management, because there just simply isn't much space in which to squeeze everything. Having said that, the results can be more rewarding as well.
Let’s begin with our first challenge: simply inserting the PC power-and-cooling PSU into the case. Initially, the power cables were too tight against the optical drive bay to allow the power supply to be mounted inside the small case.
A little bit of simple case modification was able to solve this issue. Specifically, we used some tin snips to cut part of the optical drive cage so we could fold it out of the way of the PSU cables.
With this issue out of the way, everything else fell into place without any more "hardware editing." But this doesn’t mean that we didn’t suffer from any more unexpected issues. Our next challenge was installing the Xigmatek Dark Knight CPU cooler.
There was no specific problem with the cooler itself. The included retention bracket worked like a charm and would securely mount the large cooler to the motherboard. The problem was that the cooler’s heatpipes would interfere with the DFI LANParty Jr. motherboard’s heat sinks, making it impossible to mount the CPU cooler in such a way that would force CPU-heated air towards the rear case fan, and therefore, out of the case.
We were left with no choice except to channel heated air upwards (toward the PSU) or downwards (toward the video cards). Given these choices, we would prefer to force it upwards toward the PSU so that it could be channeled through the power supply and out of the rear of the case.
Unfortunately, in this specific application, the PC Power and Cooling S75QB PSU does not pull air from below like a lot of ATX PSUs do–one fan pulls air in from the front of the PSU, and then another fan forces it out the rear. The bottom of the PSU is solid, and pushing CPU heated air upwards into a brick wall isn’t our idea of a good time.
We were left with no choice at all, really: we had to push the CPU-heated air downward, towards the graphics cards. This is, admittedly, far from ideal.
This amounts to a perfect storm of bad luck. If we were able to position the CPU cooler to push heated air out of the back of the case, this wouldn’t have been an issue, and if the PSU had an intake fan on the bottom, it wouldn't have been a problem either. I’ll take some of the responsibility for this as well, as I could have been more diligent in anticipating these issues. I’ve been spoiled working with full ATX cases with plenty of room for moving air around. So, let this be a lesson to you folks who are planning on building a portable Micro-ATX system. Pay attention to the cooling details and anticipate how your cooler, motherboard, case, and PSU will work together, as sometimes choosing what appear to be ideal components for the price isn’t enough.
In any case, the system came together well despite the less-than-ideal cooling situation. We were a little concerned about how little space the graphics cards had to pull in air. The GeForce GTX 260 mounted at the bottom of the case is particularly concerning as its intake fan pressed closely to the floor of the case, restricting the amount of air it could draw. It was as tight as a can of sardines, but it booted and ran without problems. At least at first…
We experienced some instability when running game benchmarks at 1920x1200 with 4x anti-aliasing (AA) applied. Despite GPU temperatures being reported in what seemed a reasonable 75 degree Celsius range under load, we wondered if the graphics cards were overheating.
To test our theory, we used Nvidia’s System Tools utility to manually increase the graphics cards fan speed to 100%. Our fears were confirmed when the benchmarks ran without a hitch, indicating that the cards were overheating at stock fan speeds. Would this have happened if we were able to push the CPU-heated air out of the back of the case? It’s hard to say.
Without any real way out, we let the graphics card fans spin at 100% duty cycle to continue the benchmarks and keep the system running smoothly. We’ll address the increased noise and a method for minimizing the impact of this problem a little later in the benchmark section.