As expected, default cooling performance is pretty terrible. The CPU was almost as warm as it was in the In-Win 901, which is a passive (albeit larger) case, and its temperature meant it was close to throttling. Yes, there is room to upgrade to a better cooler than we use, but the same is true of many mini-ITX cases. The fact is that having the PSU and exhaust fan both drawing air away from the CPU cooler is simply bad design. Meanwhile, although the GPU is not the worst on the charts, you need to remember the results aren't comparable since we had to switch from a hot-running GTX 570 to a super-efficient GTX 970. The real temperature of the GPU was hovering around 80°C, and it's at this temperature that Nvidia sets as a rough limit for its current GPUs by default, so it essentially hit its maximum temperature, which again shouldn't come as a surprise.
Click to enlarge
To satisfy our curiosity, we swapped the orientation of the rear fan so that it was an intake, and lo and behold the CPU temperature dropped by 15°C. The resultant delta T of 57°C is still not very good – remember the only exhaust is now the PSU, which has its own heat to deal with too. However, there's still something to be said for a case this small with just one fan keeping an overclocked CPU tamed when running at full load with a small cooler, but we wouldn't be comfortable running this overclocked set-up long term due to the added stress on the PSU components. For the GPU, there was no difference – it's simply unaffected by the cool air since it's at the top of the case, and hot air has that annoying tendency to rise. Needless to say, this is not a case for gamers – any graphics card will be essentially starved of air, and you'll likely see reduced performance as a result of it automatically clocking down when things become too hot.
Form doesn't always have to come at the cost of function, but in this case it does. The out of the box cooling is terrible – we do not recommend any gamers purchase this case, as your graphics card will be starved of air. If you're handy with power tools, you could mod some ventilation into the roof, which would help the GPU massively by providing it with an intake area right next to its fans, but you'd spoil the clean aesthetic and would still be limited to 170mm graphics cards anyway.
Click to enlarge - Here you can see we have reversed the rear fan, making it an intake
Even so, the form of the Metis is undeniably something special; it's definitely a case we'd be proud to have sitting on our desk, and for £40 we're unaware of anything else with this level of build quality on offer. However, this comes at a high cost – you are somewhat limited by the hardware you can put inside, though the ability to house an ATX PSU and a 160mm tower cooler is still pretty neat. Actually getting hardware in is a fiddly affair too, but worst of all, however, is the cooling – we're honestly baffled by the airflow design. Regardless of your cooler, you'll want to flip that fan around - this isn't hard, but it's not something we should need to be doing either. As such, we can't give the Metis an award or a universal recommendation, but that's not to say it doesn't have a home anywhere. There is a huge market for basic family, office and home theatre PCs, where efficient stock speed CPUs are the prime candidates and importantly don't need a whole lot of cooling to run safely. You could even construct a compact and attractive budget gaming rig with an AMD APU, though we'd still recommend keeping things at stock speeds to avoid pumping too much heat through your PSU's exhaust system.