Help, my new i7 build is at 100c under load

haasen

Distinguished
May 6, 2009
29
0
18,530
I put my pc together this morning, downloaded Prime95 and RealTemps 3.2.

At idle the CPU sits at 40c and the mb is about the same. As soon as I start Prime95 all 4 cores shoot up to 97-100c.

Even at only 25% utilization the temps are all above 90.

I haven't done any overclock and have a scythe Mugen cooler installed. CPU fan is set at 100% manually.

I used thermal paste --- Tuniq TX-2.

This was my first build so I ready a bunch of articles and scoured Youtube for video on spreading the paste (I used the finger in the ziplock back method).

Not sure what to do. I'm afraid to use the PC!
 

Christopher11

Distinguished
May 23, 2009
69
0
18,630
Whats the power index of your i7 920 ?>

it's 9+2+0+7 = 18 simply too pwoerfull for your mobo.

You may also check the voltage or how the cpu is plugged in.
I had the same problem with my 6000+ amd quite some time ago, I thought it was just too powerful for my mobo due to it's index but no. 6+0+0+0 doesnt look too impressive. So my problem back then was that i havent plugged the cpu correctly.

Other than that, I dont see a solution to your problem.

And have you touched it? is it really as hot? Maybe these are sensors who are afraid of numeric power of your cpu.

Maybe its just a defected CPU, bring it back and make them pay for your sufferings.

Y
 

:pfff: Muppet.
 

Lord-Ilpolazzo

Distinguished
Mar 14, 2006
182
0
18,690
Is the heatsink definitely fixed on correctly? Sounds like just the kind of thing that would happen if there was a very poor thermal connection between the heatsink and processor... it would be enough to keep things ok if the processor was ticking over but as soon as it did any serious work the power dissipation would rise enormously causing an an instantaneous unchecked rise in temperature, without the added thermal mass of the heatsink...
 

Time to clean and redo it. Use a grain of rice sized bit of thermal compound and make sure the HSF is tightened down evenly.
 

Christopher11

Distinguished
May 23, 2009
69
0
18,630


Its
power index and not power rating. Numeric theory. never heard of it?


yeah the heatsink could be the reason too. you're right. I hope the posters pc hasnt blown up o_O
 

haasen

Distinguished
May 6, 2009
29
0
18,530
Thanks for the quick and (mostly on topic) replies. =)

It's an Asus P6T Deluxe v2 mobo that I haven't done anything to, so I don't think it's my 'power rating'.

Even if the heatsink wasn't on at all, would it get that hot that fast?

I'm pretty sure the thermal is on correctly, as it matches all the videos I've seen. I can't vouch for the heatsink being tightened correctly though. I was a little cautious in trying not to crank it down too much. How snug should it be?

 

If your heatsink was not on at all the CPU would last a few milliseconds before releasing the magical blue smoke and as for how 'snug' it should be, you shouldn't be able to twist it in any direction, if you can then it's not tight enough.
 

haasen

Distinguished
May 6, 2009
29
0
18,530
Thanks. the heatsink is the Scythe Mugen 2. It attaches at the 4 corners so I can't twist it no matter what. I screwed it down until it touched the surface of the CPU, then gave each screw another 1/2 turn. I was more afraid of cracking the MB or crushing the chip.

I'll take it apart in the morning, then try again. If I pull it and there is a widespread amount of thermal compound on the bottom of the heatsink, should I just RMA the CPU?

Thanks again for your help. This is my first home build. Was so thrilled that it went together so well and powered right up. Now I'm afraid to use it!
 

oreozz

Distinguished
May 22, 2009
7
0
18,510
I've heard warnings of high ram voltages raping i7 cpus!

also fyi about being worried of crunching your cpu: I made my first build 2 days ago and was scared shitless clamping the stock heatsink to my cpu, the pressure is very very hard!
 

hefox

Distinguished
Jan 24, 2007
798
0
19,060
Make sure the heatsink is fixed corectly. If it is then clean the cpu and add again some thermal paste but not too much. And check it again.
Christopher11 thank you for illuminating us. We are sorry for not understanding your spectacular theory and your perception of this world. Please forgive us and our ignorance. Can we give you a humble advice? You should do a menthal check.
 

haasen

Distinguished
May 6, 2009
29
0
18,530
OK, took off the HS, cleaned off and reapplied the thermal paste. Screwed it back on as tight as it would go and put it all back together. Temps are now at 36c at idle, but still shoot up to 93c under load using the Prime95 tests. I have all the case fans set at 100% and I don't have the side panels on the case, so it's not a flow issue.

Is it possible to have a bad CPU? The only thing else I can think of is to install the stock HS and see what kind of temps I get with that. At least it will tell me if it's the HS or the CPU.

Thanks again for all your replies. The heatsink was the thing I was dreading the most and it seems to have come true...
 

hefox

Distinguished
Jan 24, 2007
798
0
19,060
The strange thing is that your idle temperature looks fine. I suspect that the problem is from the sensor. Try to touch the heatsink when you are stressing the cpu and see if is really really hot.
 

haasen

Distinguished
May 6, 2009
29
0
18,530
The fins don't get warm at all, but I'm afraid to run the cpu tests for any length of time due to the excessive heat. It hits 90 in about 10 seconds under full load
 

haasen

Distinguished
May 6, 2009
29
0
18,530
Wanted to thank everyone for the help.

After reinstalling the Mugen 2 three seperate times, I never could get it to seat correctly. I read on the Asus forums that the thread on the screws screws weren't long enough to correctly seat it on the CPU so I bought some plastic washers and could tighten it down more but still didn't get it below 90c at full load.

I yanked the whole thing, put back in the stock Intel cooler and was getting 40c at idle and it maxed out at 73c at full load using realtest. (and that's with 1 case fan not working yet). I understand this is normal stock cooling temps.

I'm wondering if the heatsink itself is bad. I know it was getting some contact as I tried putting a drop of thermal compound in the middle of the CPU and after it still didn't get the temps below 90c I yanked it and the HS plate had a quarter sized mark of compound on it. So either I'm not getting enough contact or there is something wrong with the plate. The fins on the HS never got warm, even when the CPU was 90c+.

Thanks again. I'm off to shop for a new HS!