940BE running too hot

[birthdaymonkey]

I just got a Phenom II X4 940BE to replace an X2 555 (that wouldn't unlock). I'm using a Gigabyte GA-MA785 GM. My case is a Lian Li PC-V351, and I'm using a Scythe Big Shuriken cooler (limited clearance in this case requires a lower profile HSF). The case is well ventilated (stock case fans replaced with higher performance ones).

The new chip is running extremely hot. With the 555 my temps maxed out at 49C under Prime 95 for 6+ hours at 3.83GHz OC. The 940 hits 70C, which is way above the max safe limit of the chip. This is at stock clock, 1.375 volts.

Of course the Big Shuriken doesn't cool as well as a tower HSF, but I've read of people using it with hex core Phenoms and i7 920 systems and they don't seem to have the extreme temps I'm experiencing.

I think the problem might be the thermal compound I'm using, which is a tube of generic stuff that my brother in law gave me (not sure of its origin). Since I got the CPU for Christmas, I don't have the immediate option of buying new TIM (everything is closed today), but I'm wondering if the cheap stuff could really be that bad?

 

[BoomerD]

I just got a Phenom II X4 940BE to replace an X2 555 (that wouldn't unlock). I'm using a Gigabyte GA-MA785 GM. My case is a Lian Li PC-V351, and I'm using a Scythe Big Shuriken cooler (limited clearance in this case requires a lower profile HSF). The case is well ventilated (stock case fans replaced with higher performance ones).

The new chip is running extremely hot. With the 555 my temps maxed out at 49C under Prime 95 for 6+ hours at 3.83GHz OC. The 940 hits 70C, which is way above the max safe limit of the chip. This is at stock clock, 1.375 volts.

Of course the Big Shuriken doesn't cool as well as a tower HSF, but I've read of people using it with hex core Phenoms and i7 920 systems and they don't seem to have the extreme temps I'm experiencing.

I think the problem might be the thermal compound I'm using, which is a tube of generic stuff that my brother in law gave me (not sure of its origin). Since I got the CPU for Christmas, I don't have the immediate option of buying new TIM (everything is closed today), but I'm wondering if the cheap stuff could really be that bad?

Could the cheap TIM be that bad? Sure it could...but since you can't go buy new today, you might want to try re-seating the HSF and see if that helps. (yes, it's a PITA...but it MIGHT fix the problem.) Use rubbing alcohol to clean the old TIM off the CPU and base of the heat sink.

Have you seen this?

http://www.hardocp.com/article/2009/04/07/thermal_paste_shootout_q209/

It gives some decent tips for applying the TIM, and discusses the different methods for different brands of TIM.

 

[birthdaymonkey]

Thanks, Boomer.

Unfortunately, I don't think I even have enough of the cheap TIM left to remount. I was mostly wondering if people thought it could be the TIM or if I'm just SOL with this CPU and fan/case setup. It seemed strange to me that there would be such a massive difference between the two CPUs, especially since the Frostytech review of the HSF I'm using reports only a ~5 degree difference between a 125W load (the 940) and an 85W load (the 555).

 

[perdomot]

I think you might be missing the fact that you've gone from 2 cores to 4 cores. Twice as many cores will cause a big jump in temps. What temps did you get with the 940 HSF? You might want to reseat the HSF after cleaning it and reapplying the TIM. Remember to use just a small amount(small pea).

 

[birthdaymonkey]

I've certainly considered the fact that I doubled the number of cores... at least I have thought about this now; I didn't really think about it before I had the new CPU installed. I never tried the CPU with the stock HSF as this was an OEM part and didn't come with one. I do have the stock cooler off a Phenom II six core; I could try it, but I know from past experience that it's LOUD.

Anyway, I can't do much of anything till I get some more TIM. I ordered some AS Ceramique (on sale) and will hopefully receive it on Tuesday.

EDIT: I tried disabling one core in the BIOS, and I'm finally able to run Prime at stock speeds (1.35V) without going over the chip's max published temp limit. I'm actually happy with three cores (the thing was on sale for $99), so if I can tweak this a bit and get a mild overclock going (new TIM and a better fan on the heatsink with my exhaust fan turned up a bit) then I should come out ahead of my 555 (which I can probably sell in these parts for $80).

All this is really a result of having a computer that serves dual duty for HTPC and light gaming, so I think the final solution is going to be getting a new machine (with a proper size case and a proper HSF) to use for games and leaving this one as a dedicated HTPC.