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fan runs faster after sleep but then slows to normal. Problem?

I've usually in all my year with Mac not had my drives sleep. I note now that when my drives awake one of the fans is spinning faster than normal. Just a little nothing crazy and then it slows to normal.


Is this the sound of a problem fan or something on my motherboard or something?


Should I do a PRAM reset? or whatever it's called these days?


Running OSX 1.6.8


Thank you.

S

Mac Pro 3.0 GHz Quad-Core, iPad WiFi/3G, iPhone4, Mac OS X (10.6.8), 30" HP Display, 22" Cinema Display

Posted on Apr 21, 2012 8:55 AM

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Posted on Apr 21, 2012 9:16 AM

When your computer sleeps and the fans spin down, heat can build up so that when it does come back to life it also may be warm enough to need to get air moving. And because in some situations it does so as a preventative measure if thermal sensor readings are not available.


Nothing to worry about. Totally normal. There was a firmware update back in.... Aug/Sept '07 to update SMC/EFI.


You also with that and FBDIMMs want to run SmcFanControl 2.3+ to insure the fans run around 800 rpm instead of 500-600 rpm to do a better job expelling and circulating air over RAM.

21 replies

Apr 22, 2012 9:26 AM in response to Steven Shmerler

Steven Shmerler wrote:


Yup. You did. But at that RPM the temp was 108F and the manual says it should be around 95F. So I therefore logically increased the RPMs


The only real issue now is who to listen to. Temp Gauge or smcFC because TG reports a higher temp than smcFC does.

I'm not sure what the temperature reading in the menu bar with smcFanControl refers to, but the PCIe slot reading in Temperature Gauge agrees with Temperature Monitor which is a widget associated with iStat. I'd go with Temperature Gauge.

Apr 22, 2012 9:29 AM in response to The hatter

One thing I left out: Air flow case


Good air flow. A place and way for hot exhaust out the back needs a place to go and help sometimes getting there. And good air flow around and in front.


Some have used a dust or cheese type cloth to keep dust outside but allow air to come into the case.


the PSU area can also hold dust and heat.


worst place: one of those computer cabinets or under a desk with the exhaust blocked or front.

On the floor carpet and dust etc and pet hair - elevated helps, I was using a low coffee table of 15-18 inches with mine.

Apr 22, 2012 10:06 AM in response to The hatter

Unfortunate new issue. I set smcFanControl to launch at boot up and it Kernal panicked my Mac Pro.


Since I can't start up without a Kernal panic how can I start my computer and set smcFC not to start at boot up.

.


I can always option start off another drive in my MP and then go into Applications on my main drive and drag smcFC to the trash?


Or is there a way to disable smcFC from starting another way?


----


Fixed it and running again on the MP.


I remembered about SafeBoot. Started that way and then went into Sys Prefs > Accounts > Login Items and deleted smcFC there and restarted without a problem. Nasty bug I seemed to find.

fan runs faster after sleep but then slows to normal. Problem?

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