Low CPU usage but High fan speed
2014-07
dhasu
Possible Duplicate:
CPU Fan is Loud, but the Temperature is OK (I Think)
The problem I am facing is the CPU fan rotates with high speed even though the CPU usage is very low, less than 10%.
I even cleaned the Dust off the Fan, I replaced the Thermal Material on the Processor. Installed an Extra Fan.
Nothing seems to Work.
Please Help.
Joey
Some mainboards/BIOSes come with faulty ACPI tables that might cause the fan to turn on too early or too late. On older operating systems this sometimes wasn't so much of a problem but newer ones more closely honor the settings there and as a result might lead to what you describe. You might want to check whether a BIOS update solves the problem.
There are also power settings in your operating system which might prevent the CPU from entering a lower power state (for example if it's forced to always run at full clock speed). You may want to check there, too.
Caffeine Coma
My Quad-Core Mac Pro tower is two days old. Initially, I was impressed with how quiet it was compared to my older Macbook Pro. Then on day two, for some reason it started running very loudly. It's not just a "little" loud- my wife walked into the room and asked what the noise was.
At first I thought this was just because I was hitting the CPU a bit (importing my iPhone library into iLife '09, and running Eclipse). But now that that's done, Activity Monitor shows a virtually idle CPU; there's nothing running that ought to be causing this, as far as I can tell.
I tried powering it off & letting it cool down for a few minutes to no avail; about 10 seconds after powering up, the box gets loud again. I took a look at it with the side cover off, and it seems to be the fan near the top middle, between the power supply and the disk drive.
It can't be a dust issue, as the machine is only 2 days old (and I peeked inside anyway just to be sure- clean). I did do a software update over the past 24 hours or so, but I can't say that it occurred immediately after that. I also did a migration of my old apps and data from my MBPro, for what it's worth.
- Why is it suddenly so loud?
- How can I monitor the fan speed and various system temperatures?
My temps and fan speeds:
UPDATE 1:
Took it to the Apple Store. They took it in the back (where it's presumably quieter) and ran a fan diagnostic; no problems were found. The guy also told me that it was "a little loud", but normal. I don't buy it. It was virtually silent the first 24 hours I was using it. They would not replace/service it in the store (grrr... that's why I went there, as directed by Apple Care) but said I could get a replacement from the online store, as it was just purchased. I think I will try that.
UPDATE 2:
Apple is letting me send it back for a replacement. Glad to see so many responses to this question mentioning that the MacPros are usually silent; it's not all just in my head.
emgee
I would image the drive and take it back. Sounds like a problem in the fan control hardware and/or firmware. I have a few MacPros at work and they are quiet. The hardware test you're already doing is also a good idea.
ridogi
Is there enough space behind it for air flow?
Is the case closed when it is powered on (it should be)?
Have you viewed "All Processes" and not just "My Processes" in activity monitor to make sure a processor isn't pegged?
Have you run Software Update to make sure you have the latest OS?
Have you run the Apple Hardware Test?
Jon Hadley
It might be that the fan (or a bearing inside it) is broken, causing the extra noise?
Or perhaps the temperature sensor is faulty and things the CPU is much hotter than it actually is?
EDIT: Also, I've heard of faulty power supplies overheating the battery and laptop, might be worth checking too.