Having space in front of the fan instead of pushing it right up against the grill has quite large noise benefits. Fan noise can be very bothersome when positioned in close proximity to inlet grill.
As long as you can evacuate the air efficiently, I don't think CPU cooling will be hugely affected by GPU thermals. Adding a fan in the bottom 120mm would help as well I think. You can look at HW Canucks' recent review of the P-ATX v2 for evidence of this. They used a 5950X and RTX 3080 in the P-ATX (much smaller than N-ATX) with a 59mm tall cooler and still got good results.
If you do find CPU cooling inadequate, a very popular solution is to 3D-print a fan shroud or make one out of cardboard to ensure the CPU cooler ingest air from outside the case.
I fully agree about noise increase when a grid and a fan are direct neighbours...like PSU...but...
However leaving 9mm above Noctua L12S is leaving me unsatisfied...but that's not end of the world..
Especially as there are other options : ID cooling IS-60 or Black ridge with 25mm fan..
Hardware Canucks video, as using ATX motherboard is instructive as Thermalright AX100 is fitting just nicely on ATX MB..
Love this space about CPU on ATX motherboard vs tiny space on Mini ITX ones. (by the way they put a 5900X in it, not 5950X)
By the way, Zen 2 and above CPU (stock settings) are friendly to small cpu cooler as they adjust speed/vcore to it. Performance impact remain minimum.
I've tested Cryorig C7 on stock Zen 2 R7 3800X inside my Cerberus-X succesfully.
https://smallformfactor.net/forum/t...erberus-x-complete-build-log.2007/post-185864
Basically SFFTIME N-ATX will offer ATX MB & 3 slots GPU support within 14l with following compromises :
- PCIe Riser constraint (still worried as Gen 4 riser still struggle to arrive on market)
- Average CPU cooling (up to 105w somehow) (completely fine for Ryzen CPU.. Not really for too much power hungry Intel)
- Not available yet..
I will definetely follow its evolution..