So, from this post [forums.macresource.com] I replaced my internal HDD with an SSD. During this process I cleaned all the dust from the inside. Prior to the swap, running SMC FanControl at mid-level speeds, my CPU temp was normally around 99F. The new normal is 127+ and GPU often rockets over 150. Activity Monitor doesn't show anything out of the ordinary. Maybe I should have left all the dust alone

Fan or sensor cable disconnected ?

Shouldn't be - I only disconnected 3 cables when I open it (propped the LCD with a screwdriver like advised in the original post). Thought the SSD would make things even cooler inside.

Make sure the sensor is properly in contact with the new ssd.

Try turning off SMC fan control and see what happens to temps. 99% of the time it's useful, but I've seen it mess up temps as well.

Zap the pram, and reset the SMC, too. It's basic, but when I installed an SSD into my '09 imac last week the video went wonky and I was sure I'd damaged the hardware. Zapping the pram fixed all issues instantly.

EDIT: Spotlight indexing can temporaily cause the SSD to run hooter too, on a freash install.



Edited 1 time(s). Last edit at 02/13/2015 09:03PM by p8712.

Any chance the HDD was such a bottleneck that it kept the CPU from revving up as much as now?

Turned off SMC fan control and fans haven't changed - even killed it in activity monitor. May have to reboot to kill it totally. Will try zapping pram and resetting SMC. I don't believe spotlight is indexing (mds & mrs_stores is idle in activity monitor). Also, I had cloned the hdd to the ssd, so it shouldn't be indexing. Maybe I should wipe the index and let it re-index overnight?

Black - could be, but I had been running from ssd externally for about a week before replacing the internal - would I have noticed a temp change during that time? I'm now wondering if I may have blown dust into the fins of the cooler. In hindsight, I should have used a vac instead of canned air (I'm used to working on pc's where I can see the cooling fins and reapply thermal paste if I have to remove it). I'll have to disassemble the whole iMac to check that part - really would hate to have to go that far! Guess I'll try the simplest things first...

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rouderon
I'm now wondering if I may have blown dust into the fins of the cooler.

Could be. Remove the CPU fan and blow the fins. I use an air compressor on my macs, clears every particle out. A few blocked fins on the imac could be doing this. Do the same for the optical and hdd fans, even if they look clean.

I still think the SMC might be at fault. It's usally related to fan wierdsness.

Well, reset smc and zapped pram. Started with no SMC FanControl app and CPU at 150+ / GPU now pushing 170. On the plus side, iMac is so quiet without SMC FanControl running

Looks like I need to open this up again. I do have an air compressor - will use it on the fins. Is the fan [that blows the fins) easy to remove or will I have to pull the motherboard?

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rouderon
Well, reset smc and zapped pram. Started with no SMC FanControl app and CPU at 150+ / GPU now pushing 170. On the plus side, iMac is so quiet without SMC FanControl running

Looks like I need to open this up again. I do have an air compressor - will use it on the fins. Is the fan [that blows the fins) easy to remove or will I have to pull the motherboard?

Do'h! Sorry to hear. The CPU fan is easier thaninstalling an ssd.

Here you go

My '09 runs typically at about 99 degrees f, maybe 120 under heaviest load.

An '08 might need new thermal paste, as you noted, but it's a pain, you pretty much have to stip the insides down to nothing. Last resort. Double check your fan/sensor cables first!



Edited 1 time(s). Last edit at 02/14/2015 09:42AM by p8712.

Been reading up on trim and seems pretty gray - so what say ye: trim or no trim (enabler)? Have a 512gb Crucial M100 drive. Trim support is showing 'no' in the system report.

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rouderon
Been reading up on trim and seems pretty gray - so what say ye: trim or no trim (enabler)? Have a 512gb Crucial M100 drive. Trim support is showing 'no' in the system report.

No reason not to if the option is available to you.

Is there a place to enable it without having to download a 3rd party app (like Trim Enabler)?

No. Get Trim Enabler. Just don't expect fireworks.

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rouderon
Is there a place to enable it without having to download a 3rd party app (like Trim Enabler)?

Not if it doesn't have an Apple ROM.

Just finished 'dusting.' All I can say is - wow! Should have taken a before pic (thought about it after the fact). Don't know if any air would have been able to get through the fins. Thanks again for the air compressor tip! Worked much better than canned air. Need to turn off SMC FanControl (was set to start up at login). So, with it running the temps are fluctuating between 82-84F and GPU diode is 108 - 112F. Very, very happy!! Thank you all for your priceless help (as usual)

Now to figure out trim. Do I need the paid version by Cindori (which disables kext-signing in Yosemite: [www.cindori.org] )? Seems pretty convoluted way of using trim since performing any hardware maintenance may cause the grey boot screen.

I would skip trim myself. Your ssd is likely going to be fine and outlast that machine even without trim.

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rouderon
Just finished 'dusting.' All I can say is - wow! Should have taken a before pic (thought about it after the fact). Don't know if any air would have been able to get through the fins. Thanks again for the air compressor tip! Worked much better than canned air. Need to turn off SMC FanControl (was set to start up at login). So, with it running the temps are fluctuating between 82-84F and GPU diode is 108 - 112F. Very, very happy!! Thank you all for your priceless help (as usual)

Now to figure out trim. Do I need the paid version by Cindori (which disables kext-signing in Yosemite: [www.cindori.org] )? Seems pretty convoluted way of using trim since performing any hardware maintenance may cause the grey boot screen.

I'm so glad the compressor worked! If you buy an inexpensive compressor and hose, you've got an inexaustible source of cleaning! Works much better than canned air. Enjoy the speed boost fromt he SSD.

Yes - so much better than canned air - good call!

DO NOT USE TRIM ENABLER OR ANY TRIM HACK UNDER YOSEMITE.

IT PATCHES NVRAM TO DISABLE KEXT-SIGNING TO ALLOW THE HACK TO WORK AND IF YOU EVER ZAP PRAM OR THAT ONE LITTLE TINY BIT SOMEHOW GETS TOGGLED THEN YOUR MAC WON'T BOOT.

...But go ahead and use it on any version of the OS prior to 10.10. It'll be harmless and potentially increases both the speed and longevity of your SSD.

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So, I think you're saying...

Ha! Thanks for the heads-up - I was reading their site and trying to figure out why I'd use it if it's got such great potential of killing the boot. Think I'll hold off (iMac is running 10.10)

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rouderon
So, I think you're saying...

Ha! Thanks for the heads-up - I was reading their site and trying to figure out why I'd use it if it's got such great potential of killing the boot. Think I'll hold off (iMac is running 10.10)

The benefit is that it reduces writes to the drive and theoretically extends the life. Personally I would be happy with the value I got from any of my SSDs if they only lasted 3 years-- best computing money spent in the last decade.

[www.crystalidea.com]

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Edited 999 time(s). Last edit at 12:08PM by jdc.

So, is Macs Fan Control better than SMC FanControl?