I just installed Noctua NH-U12P SE2 (two fanned) on my Q9550. I used the Noctua NT-H1 heat paste. Additionally, I have the cooler fans running or normal speed without the adapters that slow down the fans thus reducing the noice. Also I have applied no overlocking.
However CoreTemp is still displaying idle temperature of 40-44 C (with two cores running at +2-4C above other two constantly). On Prime95 maximun heat test the temperature doesn't go much above 50C, 53-54C at maximum depending on the core.
Am I wrong if I say that the idle temp seems bit high for non-OC setup? The temp under torture doesn't seem too bad but I have to way I was expecting bit less from big, expensive cooler of this caliber.
This masterfully drawn work of art displays my fan setup (Before you ask, I did took photos first but could no find my camera cable, so I had to rely on illustration like this):
Red boxes are fans and arrows show the direction of air flow.
Note that there are three different brands of 120m fans there, the numbers in the pic resemble the following:
1)Antec 3 Speed
Could it be that maybe some of the fans are too weak in comparison to the new Noctua fans and they somehow mess up the air flow causing the CPU to heat up more? Or is my fan setup and direction of air fundamentally flawed? Or is my case (Antec Sonata III) just too tight and crowded, since the massice cooler doesn't really leave much space around itself?
Nothing wrong with those temps. You've got to remember that when the cpu cools down, the fans will spin down as well so they keep quiet. This has the side effect that the cpu idle temperature will be a little higher than what you are looking for.
The alternative is to enter your bios and set your cpu fan to 100%, while this will lower your cpu idle temperature by a few more degrees it will also sound like an aeroplane taking off.