Title says it all
The best fans are SP fans (Static Pressure) not air flow. The top ones are Noctua(despite awful coloring) Corsair and EKWB Vardar fans
specifically what noctuas?
You need 140mm fans with the X61
I have these on my Nepton 280L and they work great. Bit on the noisy side for me when they get up there in RPM but thats just because my surroundings are usually quiet.
Any fan spinning at 2000 rpms is not going to be quiet. The non industrial noctua fans are much quieter. You could always run the fan with a PWM setting.
It is PWM controlled. It starts to get loud around 1400 - 1500 RPM, but it doesn't reach there often, usually when temps are over 75C which doesn't happen often or for long if it does happen.
Those are 120mm fans and he needs 140mm for the X61.
Lemme put up the 140mm version then.
I just did. :) but the industrial version..
Thanks for that pointer! Forgot X61 was 140
Akasa also makes pretty good SP fans. Their pressure values are higher than those typically offered by the three you mentioned, at the downside of generally being louder.
And Noctua's redux (and industrial, as mentioned already) fans aren't too bad
I would go noctua industrial with the static pressure because they don't have the poop brown. Or if you like the brown, you can go normal noctua.
The stock ones if you want to make sense value wise. Performance wise that all depends on your noise tolerance. If you are going to replace the fans you might as well look into getting a all around better cooler.
EKWB Vardar, but a bigger rad makes more difference than fans
I like the Fractal Design HP14 for radiators. If more RPM are desired; some other good fans have been mentioned as well.
I love the E-Loops :) I was so happy to see they added 140mm versions as they only had 120mm for a while. I use the 120mm eloops as case fans on my itx build.