# CPU idle temp rises after new GPU installation



## Steven7 (Jan 19, 2007)

Hi guys I was upgrading the GPU of my old PC (AMD Phenom 555 BE with stock cooler) from 8600GTS to a 9800GTX I got for free. The installation went fine but I noticed that the idle temperature of my CPU rises from ~38 to ~47 degree Celsius. The GPU idle temperature remains roughly the same as before though despite its 2 different GPU.

I wish to ask is such temperature increment okay? I understand the fact that 9800GTX is sucking more power (2 6-pin power connector instead of 1 4-pin molex as before). So my theory is the GPU is causing the PSU to work harder and generate more heat. My PSU is top mounted with fan blowing in the downward fashion and I guess this causes the mainboard/CPU to become warmer?

Second reason may be the GPU is warming up the chassis? But as I mentioned its idle temperature remains roughly the same as before.

So guys, is this okay or should I get an aftermarket cooler (like CM HyperTX3) for the CPU?


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## gcavan (Aug 13, 2009)

> My PSU is top mounted with fan blowing in the downward fashion


If you look closely, you will probably see that the fan is drawing air in and pushing it out the rear of the case.



> Second reason may be the GPU is warming up the chassis?


Possible, though I doubt the result would be more than a degree or two.

Third possibility, and IMO more likely: When you were installing the new card, you disturbed the CPU cooler (however slightly) which broke the bond of the thermal compound. Fully remove the cooler, thoroughly clean the mating surfaces of the heatsink and processor, apply new compound and reinstall.


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## Steven7 (Jan 19, 2007)

Hi thanks for the quick reply.



gcavan said:


> If you look closely, you will probably see that the fan is drawing air in and pushing it out the rear of the case.


Oh I guess I should mention my PSU which is a Cooler Master: Extreme Power Plus 550W but to be honest I can't feel the hot air is being pushed out when I put my hand over there. 



gcavan said:


> Third possibility, and IMO more likely: When you were installing the new card, you disturbed the CPU cooler (however slightly) which broke the bond of the thermal compound. Fully remove the cooler, thoroughly clean the mating surfaces of the heatsink and processor, apply new compound and reinstall.


Well I checked and the heatsink is being held in place quite tightly and in fact I just applied Arctic MX4 not long before the new GPU installation and that's the reason I got ~38 degree in the first place.


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## WereBo (Apr 5, 2008)

Hi Steven7 :wave:

It's also possible that the newer GPU-card has more 'complicated' drivers, which run under the CPU - Although the CPU is idle, it'll be using more background processing than the earlier GPU's drivers required :wink:


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## Tyree (May 10, 2009)

I would agree with gcavan about the possibility of the CPU heatsink being disturbed.
How old is the PSU? It's a lower quality unit made by Seventeam, not 80+ certified and 2 yr.warranty so it is a possible suspect also.


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## Steven7 (Jan 19, 2007)

Thanks for all the comments guys. Actually both cards share the same driver (NVIDIA 320.49) and it really shocks me when the idle temp rises so many (~10 degree).



Tyree said:


> I would agree with gcavan about the possibility of the CPU heatsink being disturbed.
> How old is the PSU? It's a lower quality unit made by Seventeam, not 80+ certified and 2 yr.warranty so it is a possible suspect also.


I guess I'll check the heatsink issue again and perhaps installing the old GPU again to see if the temperature drops back. Anyway regarding the PSU, its almost 2 years but before I install the new GPU I logged the temperature which is okay, the temp rise happens after the installation.


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## Wrench97 (May 10, 2008)

What is the load temp of the CPU?


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## Tyree (May 10, 2009)

Steven7 said:


> Anyway regarding the PSU, its almost 2 years but before I install the new GPU I logged the temperature which is okay, the temp rise happens after the installation.


The new GPU requires more power. :smile:
The free GPU may also have some issues causing even more power draw?


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## T_Rex (Oct 21, 2012)

That specific power supply has relatively weak split +12 v rails. To actually tap into the full +12v capacity of the PSU you may need to use one regular PSU vid connector, and then use a molex-to-vid-pin connector for your other connector on the card.


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## Tyree (May 10, 2009)

I believe the 9800GTX only requires/has one 6-pin power connector.
I am also more than hesitant to recommend using power adapters.


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## T_Rex (Oct 21, 2012)

^Normally me too Tyree I agree, but there are some PSU's out there that only have one GPU connector, and in that case an adaptor is needed anyway if the card requires two. I had a customer that had the 630 Raidmax (GULP yes - he bought it himself without asking my advice) and it was the same issue. His HD 7950 needed two connectors, and though the PSU had two it was only delivering on one PSU +12v rail to his card initially (22A). After connected to molex adaptor everything was fine. Afterwards I promptly replaced the power supply anyway LOL. .

There are many cheap PSU's on newegg with split rails just like the OP's but limited connectivity.


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## gcavan (Aug 13, 2009)

The vanilla 9800 GTX peaked out at around 175 watts draw; thus the requirement for 2 x 6pin PCI-E power connectors. Then there were the OC and GX2 versions which were even bigger power hogs. The bottom photo is actually a 9800 GTX+ which was built on the 55nm platform and used much less power than the vanilla GTX (>100 watts for the non-OC version)


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## T_Rex (Oct 21, 2012)

^Yes more refined version of the 9800GTX, I remember well I ordered more than a few. Most opted for the 9800GT single slot card, which was a refresh of the 8800GT. I personally ran a 8800GT for quite some time during those days. x850Xt before that :grin: What a wind tunnel that thing was!


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## Tyree (May 10, 2009)

If the OP post back with a Brand/Model of the 9800GTX, we can be more effective with our assistance.
If a PSU does not have the required power connectors, common problem with lower quality PSU's, it should be replaced with one that does. Power adapters are just asking for more possible problems.


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## Steven7 (Jan 19, 2007)

Hi guys, its a ASUS 9800 GTX+ DK TOP and requires 2 6-pin but I thought my PSU have 2 6-pin power connector which is sufficient? I guess may be its making the PSU work harder and thus more heat is being pushed out from the PSU? This is only my theory and please correct me if I am wrong.


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## Tyree (May 10, 2009)

Your PSU has the required 2x6-pin connectors but it's low quality and a possible cause of the problem.



Wrench97 said:


> What is the load temp of the CPU?


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