when I said I wouldn't be overclocking I should have been more clear.
Nah, it's alright. I wrote half of that at 2am, so ignore most of what I said.
Regarding the case, the NZXT website states on the H440 product page:
"GPU Clearance With HDD Cage: 294mm
GPU Clearance Without HDD Cage: 428mm"
Which means your card and any other 390 will fit - you'll just have to take out the HDD cage(s) which could be blocked by the GPU. (If you had a smaller graphics card, you wouldn't have to - but because the H440 seems to have a zillion HDD cages, I think you'll be more than fine.) I suspect the HAF 912 could fit any 390 as well if you did the same thing with that, but since there was no clearance listing with cage(s) removed, best not to take the chance. Cooler Master, you ain't helpful...
Just checking - do you actually need 2 extra fans? The case you've chosen already comes with 3 in the front and 1 in the back. And there is evidence (11:50 - 12:10 of
this video) that having more fans doesn't necessarily make much of a difference. I mean, my mATX case has a single intake fan at the front at floor level, and that's it. I'm getting 20 idle/40 load temps on my CPU, which is at the top, in the back of the case - and my cooler isn't all that different from yours. Plus, you only have 3 fan headers on that motherboard, so you're either going to have to remove the fan (the difference between 3 and 4 is negligible anyway!), plug it into a fan controller or plug it into the PSU (but have it run at full speed all the time, which is loud and annoying). If I were you, I'd remove the exhaust fan (
here's why). But it doesn't really matter what you do - you just probably don't need any more fans than the case will come with, because you won't have enough headers anyway.
And regarding the power supply, which is arguably the most important component in any build, yeah... you'd probably be better off with the Super Flower. It's in the top tier of
this list, vs tier 4 for the CX. Sorry I didn't point that out earlier. It's definitely worth paying the extra.