Post
by darunium » Sun May 09, 2010 10:05 am
Thanks for the great insight as always Luca,
Here's what I ended up doing, I looked into the Scythe Ninja 2 and the CNPS10X Flex that you suggested, as opposed to the Scythe Grand Kama Cross. Because the Ninja 2 doesn't have a PWM fan header and I'm not sure the 10X Flex will fit when a fan is attached (the heatsink dimensions fit, but images I've looked at seem like a 120mm fan will actually stick out a little above it, hard to tell though I'm not sure of that), I ended up just going with the Grand Kama Cross. The Zalman CNPS9900 I also considered and looked at a lot of reviews, and while the cooling beats the GKC, its low-speed noise loses out, which is obviously important to me.
The result is that with the GKC in the system at stock speeds my cooling seems sufficient, here's where I'm at:
(again, I only care about idle noise and load cooling, not idle cooling beyond minimum or load noise)
(this is all with no additional case fans, only the ones included with the P193: 3 exhaust [2x140mm on top, 1x120mm in back], and 1 intake 200mm side fan. I purchased one more 120mm 800RPM@12V 3-pin Scythe Slip Stream for the front intake to improve flow into the case, although as is when I put my hand in front of the case front air intake I feel breeze blowing in.)
Room Ambient ~21C
- At idle with all the fans turned down, cooling seems sufficient with the CPU at 38-42C (HDDs in low-mid 30s, case ambient 37-42C)
- At idle with all the fans turned up, CPU at 34-38C
- At 100% CPU load (Prime95) with all the fans turned up, CPU at mid-50s
(Temperatures measured with SpeedFan, RealTemp, and Asus's monitoring utility)
I should also mention that I think I added WAY too much thermal paste, so at some point I may take off the heatsink, redistribute the paste, and put it back on to see if that helps with temps. I'm hoping it'll just kind of work itself out has the GKC is a super hassle to take on and off while in the case due to its wide profile.
Are these operating temperatures acceptable?
In terms of idle, low-fan-speed noise, I'm not sure how I feel about it. I slept with it last night OK, but I could still hear it from my bed. It isn't loud, in that if you are not asleep, you won't hear or notice it, but when you lie down and there's no cars passing at night, it is still audible from 10ft away, and if possible I'd like to try and get it below that.
Dissecting the noise, here's what I've got (from 10ft away and closer reexamination from right in the case):
I've discerned, I think, 2 real problem noises from 10ft. One is a type of whistle, higher pitched than other tones but not truly high pitched, while the other is a similar pitch range, perhaps a little lower, but more of a drone. From observation:
- The HDDs are inaudible
- The side fan is not bothersome, you can make out it's low drone but it is very low and very soft, even set on medium.
- The case exhaust fans are audible, albeit quite a low tone. Subjectively, from 10ft away, they are slightly below whisper-level
- The CPU fan (140mm on the GKC) is similar to the case fans when down at 500rpm.
- The GPU fan (HD5850 OEM) I *think* is generating one of the two problem noises, it is a small 92mm fan that, getting my ear close as possible to it, I think is generating the second noise I mentioned above. It's hard to be sure though because as I get closer to the case, the problem sounds become more delocalized.
- The other sound, the whistling, I think may be an actual whistle in the case. I can't tell where it's coming from, and it is present even when the case is open on one side.
Turning the case and CPU fans up has zero effect on the two primary problem noises, I will try turning the GPU fan down manually to see what effect that has.
- I don't know what kind of noise the PSU is making except up close. Up close to the back of it there is a high pitched noise coming from inside (CP-1000), but that is totally lost from 3-5ft away. The fan I can't detect anything other than a soft low drone.
EDIT: I added the Scythe Slip Stream 800rpm fan in front of the case. CPU temperatures were brought down only 1-2C. The noise of Antec fans at low speed seems about the same up close, so replacing them may not yield any sound improvement.
So that about sums it up. I may just try to live with it as is, or see if turning the GPU fan down helps. I considered trying to swap out the CPU heatsink, but it seems like it meets my cooling and noise needs at the moment (as well as anything that is, I don't know how it would hold up to CPU OC'ing, but as you mentioned there's not a lot in that height limitation that will quietly, although I don't care about noise when OCÃng), so that doesn't really solve the problem, how to get the low-fan-speed, idle CPU overall system noise down further.
Another strong consideration of mine is swapping out the three antec TriSpeed exhaust fans with quieter PWM case fans (although my MoBo only has 3 non-COU fan headers, and I want to put one in the front, and the MoBo females are all 3-pin...), but I don't know if those are really the culprits, and how much I could gain. The 800rpm Scythe Slip Stream will be a good test, if that is greatly quieter than the Antec TriSpeeds, then swapping will start to seem like a solid idea.
Another possibility I considered but have no basis for is: could changing the CPU heatsink reduce system noise (at *idle,* so already low temps) even if the heatsink itself doesn't get any quieter? I'm thinking, in particular, of the 'whistling' noise I'm encountering.
Anyway, thanks for the help and insight, I hope my experience and this insight will benefit others as well.