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h9826790

macrumors P6
Original poster
Apr 3, 2014
16,666
8,594
Hong Kong
Did anyone here ever apply arctic silver 5 to replace the stock thermal paste on your GPU?

I've seen someone said it can improve the cooling, so lower the fan noise. I have a Sapphire 7950 Mac Edition card. I would like to get the most performance from it, but lower the fan noise as much as possible after OC. Just wonder should I try this.

Anyone have experience on this? Good or bad?

I know it's possible to kill the card. Of course I am not looking forward of that. However, if I know there is a possible good return, I don't mind to take the risk. I have a backup graphic card anyway if anything goes wrong.
 
If you were to clean the old thermal paste up really good and apply new one, it should improve cooling. I've fixed numerous GPUs both standard PCIe size, and the ones in iMacs using a process called reflow. In order to do that, the heatsink has to come off. I apply AS5 when putting the GPU back together and they definitely run cooler.

Clean out the fan while you have it apart as well.
 
From my experience I saw great results with an aftermarket cooler over stock. I had two 5870s fail on me and went for an AC cooler on the third. Aside from not exploding again it was also whisper quiet even on high load. I have now upgraded the card but not moved put a replacement cooler on and I do miss how quiet it was. Of course while you're in there tinkering some new paste can help but for overall effect I would go with a better cooler
 
Thanks for your sharing. Any suggestions for the 3rd party 7950 cooler? Are they usually a little bit larger than the stock cooler? I am a bit worrying they may not fit it a cMP.
 
Yeah they are sometimes bigger, mine took up the space for the above pcie slot so it was triple height as apposed to the normal double that yours is now. But I guess it depends on if you need the slot or not. Mine is an arctic cooling one and the ones they do are usually compatible with a range of cards so have a fish around. The cooler for the 5870 supposedly also fits my new 7950 so i might get around to it when the warranty on the card is up
 
Thanks for the recommendation.

The Accelero Xtreme IV looks very good, however, the back plate make it can't fit in the cMP.

And the Accelero Xtreme III is not available at this moment.
 
I doubt if it's possible to run it without the back plate.

Screen Shot 2014-10-29 at 22.45.58.jpg

It seem the back plate is one of the key to hold the heatsink on the GPU.

If I run it in slot 2, it's triple height will block both slot 3 and 4, leave me only slot 1 to use. However, I need 2 more slots to run my Tempo SSD and USB 3.0 card. So, it's not an ideal option as well.
 
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I'm sure it is but you could use small nuts and washers to hold it. Back plates are mostly there to give cards added rigidity that you don't need because cards are mount upside down in Mac Pros. I'll grant you it's a $100 gamble but that's kind of why I'd do it, to make it work when it shouldn't.
 
Keep in mind that most (if not all) AC coolers are 2,5 slot high. So for those who have all 4 occupied it could be a no-go.
 
Thanks for the info. Just finish the re-paste, I did it 3 times in order to get the correct amount of AS5. 1st time too much, GPU slowly getting hotter than before. 2nd time too less, the temperature increase so quickly, fan goes to 100% after 3s of GPU test, big failure.

And finally the 3rd time, it seems I did it correctly. The idle temperature now about 5C lower. The max temperature under stress seems no change at this moment (it didn't go worse than stock anyway), but AFAIK AS5 take almost 200hr to get stabilise, so it may get better later on.

Anyway, it's my very 1st time to open a graphic card, good experience, learn something and gain more confidence today. :D

Update 1: I just don't believe that there is no improvement under full load. So I did it the 4th time. And bingo! 5C cooler when performing OTTC error test with very low speed fan profile (never above 33%).
 
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