The only reason I ask is because you can't fit two fans on the side - there's not enough clearance above the U9S for a fan. So if you're planning to use more than one 120mm fan then thet means one on the side (nearest to the front of the case) and one or two on the case floor. I'm going to respectfully disagree with @Vault-Tec here: in the NCase you might find that you're better off using the bottom fans as exhaust (although it's worth trying both). This is because the NCase is so wee that the GPU effectively cuts it in half into two sections with almost no airflow between them - air from bottom intakes has nowhere to go. It'll depend on your card to a large extent but generally the principle of heat rising isn't particularly applicable for this case. Even with a blower you might be better off with those bottom fans as exhaust. And given the tight clearance at the bottom of the NCase, slim fans may well be better than normal thickness ones. Fortunately Noctua have some nice 120mm x 15mm fans which are very good.
And as a quick addendum: you might well find that fans on the case floor make zero difference regardless of their orientation - with the NCase there's not much space between the fans and the GPU, the case floor doesn't have the best ventilation, and the stock feet don't give you much clearance between the bottom of the case and the surface that it's sitting on. All three of these combine to limit the benefit of bottom fans.
I used a case smaller than the M1 quite a while back. Well, definitely smaller in width. The stock layout looks like this. So I decided to spice it up a little, adding two 120mm fans to the outside bottom (but covered by the curve in the side panels) And the cooling went from pretty dire to exceptional. It was like a wind tunnel. I am not familiar with the M1 at all, nor in particular ITX. It was the first, and last, ITX build I will ever do. No fun, working in cramped quarters and literally sent me around the bend.
Jonsbo something. I really can't remember now.. I finished the build and decided it was silly. My uncle was diagnosed with cancer, and my aunt's PC was struggling so I gave it to her. She loves it, her first SSD.
Interesting stuff. My understanding with heat convection was that it was pretty much out of the running as soon as you have a fan of any consequence running. Thinking about the M1 design, I did think that the front side mount would be the only useable one, and that the floor is pretty poorly ventilated for airflow. I have also been looking at @mnpctech machined feet to add a bit of space under the case. At LAN night he SG 13 has been running on the carpet by my feet historically, and I was worried about the M1 intake/exhaust on the bottom in that position. I think that the narrower footprint may well allow me to place it on the table next to the monitor on the desk. So, 1x 120mm intake fan on the front side mount plus an experimental 120mm bottom exhaust away from the blower GPU intake. I hope to start moving case later this week. I'll throw up some pics as I go. I don't have the U9S yet, so it will be interesting to see how the C7 fares for starters @bawjaws, does the SFX PSU orientation make much difference? I have a Corsair SF600 with a cool/low load fan off setup from what I understand. It could either take fresh air in from the vented side panel or in the other orientation, have fresh air blown into it by the 120mm intake fan.
Ta. The case itself? beautiful. Absolutely beautiful. We're talking Apple fit and finish here. I guess if I could make do with two small (in stature) hard drives and not keep swapping out GPUs and so on I could have easily lived with it. Once built it was a lovely little thing to behold.
I don't think it makes much difference to be honest. I have my PSU with the intake on the outside, but when I flipped it there wasn't any notable difference in temperatures, fan noise or fan activity. I'd just go with whatever orientation gives you the best cabling outcomes - I believe the Corsair SFX PSUs come with relatively stiff stock cables, so you might find that one orientation is better than the other for bending cables and tidying them away.
I run an AIO in my gaming rig and ..... I am not impressed tbh and thinking of going back to air cooled. I have had 2 pumps fail ( my pc is on 24/7) within a year and my third is noisey now but working fine. They are coolermaster AIO's I replaced the fans for Noctua ones to quiet it down. It does what its suppose to but the pump failure has put me off getting another. If and when this one goes I will go back to air cooled I think.
If your PC is on 24/7, then absolutely go back to air cooling. You might wear a fan bearing out every few years - cheaper than a £100-150 AIO.
BTW Tre I used to use one of the Noctua 92s. It was good, but not great. I got 500mhz further with my Phenom 2 940 on a D14. that said it was pretty quiet, and did a better job cooling a Core 2 Duo to 3.9ghz.
OK then, it looks like a U9s + additional 92mm fan on the case as exhaust to be ordered and a couple of 120mm fans from stock to test it all.
Fwiw, I used to run a fan on the case floor for my blower-style GPU, but it made no difference to temperatures at all, even with a bit of DIY ducting between the fan and the GPU. I just have a U9S with two fans and a 120mm intake on the side. Actually, that reminds me that my U9S is currently pointing bottom-to-top because I decided to rotate it 90 degrees to see if it would help with temperatures. It didn't, but I was too lazy to switch it back. It does mean that the top of the case is now absolutely ideal for my cat to sleep on, though