R9 295x2 Gpu1 much hotter than GPU2

mxtoddy1991

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Nov 19, 2014
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Hi guys,

I have been running my 295x2 for around six months now and have not really had any problems, but recently I started to notice FPS drops in my games. Upon further inspection it appears that GPU1 (according to afterburner) is idling at around 51C and GPU2 at around 32C. I decided to run 3dmark to see what impact it was having, and found that within seconds of the test launching, GPU1 hits it's thermal limit at 75C whilst GPU2 (also 100% usage) is around 45C. So it throttles and I lose a huge chunk of performance.

I'm running a custom loop, with an EK waterblock on the card, I've noticed there appears to be some bacterial growth in the block, especially around GPU1. I've put in some ethanol, so hopefully this will flush it out. Do you think it could purely be the growth thats having such an impact on temperatures? Or am I dealing with something else?

Thanks in advance for any help :)
 

rubix_1011

Contributing Writer
Moderator
75C isn't the thermal limit of GPUs, but it is concerning why it might be hotter than the other card. How is the loop setup? Are the GPUs in serial or parallel? If it was a flow issue, I would think that both would suffer the same problem and be getting warm. It could be a seating issue of the block on the card, but uncertain at this point.
 

mxtoddy1991

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Nov 19, 2014
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The 295x2 has a thermal cap built into the bios of 75C, when it hits this it throttles the card to maintain that temperature. It is also a dual GPU card, so as to how they're set up I do not know.

I have reseated the block, but the issue still persists, it's just odd as it worked fine up until recently when i started to notice this issue :/

 

rubix_1011

Contributing Writer
Moderator
75C seems pretty low when considering other GPU thermal ceilings, but that is interesting.

Also, are the GPUs in serial or parallel? I've seen where some are setup incorrectly so the I/O of the water flow simply goes through one port and out the same port on the other without fully circulating within the block.