Asus CUSL2 too hot!!

[RickH]

I inherited an Asus CUSL2 MB, BIOS 1009 and am making a machine out of spare parts. I added a Celeron 566@850, it runs stable at 1.75 volts. The CPU ran fine for 2 years in a BX chipset MB at the same voltage with the same HSF. In the CUSL2 the temps are about 32 at idle and 45 non-overclocked running Prime95. Overclocked to 850 @1.75 volts the idle is still about 32, but the Prime95 temp goes to 65!! Both Asus Probe and MotherBoard Monitor5 give the same temps. Any Ideas?? R

 

[RickH]

?

 

[Thor86]

I use the same board with a P3 1Ghz EB 133fsb socket 370 and it never goes above 50C. I would double check the heat sink and fan on your setup and make sure it is getting good contact with the cpu core. Are you using any thermal compound?

 

[CraigRT]

Asus boards always read high.. it is very likely the temperature is nowhere near that in reality. is the HSF extremely hot to the touch? if it's not, I wouldn't worry.

 

[RickH]

I am using AS, the HSF is sitting on the core, not the socket. The HS is not hot to the touch. Maybe this version of the BIOS gives incorrect temps, a very early one did. The same CPU was in a BH6 for years at the same voltage with no problems. I was worried that the heat was not being conducted to the HSF, but it is sitting perfectly. Thanks for the ideas. R

 

[oldfart]

Asus boards always read high..

Actually, Asus reads low. Abit boards tend to read high. As far as the "touch" heat of a heatsink goes, it should be warm. If it is not, it is not doing its job of conducting heat away from the CPU.

 

[RickH]

It is warmer that the metal case. The chipset heatsink (no fan) is warmer than the CPU HS. If it was just the BIOS version making the sensor read incorrectly I would think the idle temp would be outside the expected range. It's 32 at idle, but soars to 65 with Prime95. RRRRRRRRRR

 

[Thor86]

Use MBM5 for the CUSL2 for fairly accurate temp readings.

 

[RickH]

Both MBM 5 and Asus Probe give ~ the same value. Sixty-five stinking degrees with Prime 95!!!!!!

 

[Thor86]

Originally posted by: RickH
Both MBM 5 and Asus Probe give ~ the same value. Sixty-five stinking degrees with Prime 95!!!!!!

Hmm, ok, what is your room/ambient temperature? Are you using any case fans? I'm using a medium tower, no case fans, and even a 10krpm SCSI drive, and the office tempurature is around 22-25, and MBM5 never goes over 53 degrees celcius under full load with Prime95.

 

[RickH]

Room temp is ~25. One case fan. The temp at idle is ~30, at normal clock speed or overclocked. Start Prime95 or Quake II demo loop and it jumps to 45 at standard speed or 60-65 in two minutes overclocked. The heat sink never feels very warm. I thought maybe the HSF wasn't sitting just right, but it looks fine. Used AS paste. Very strange. R

 

[Thor86]

Originally posted by: RickH
Room temp is ~25. One case fan. The temp at idle is ~30, at normal clock speed or overclocked. Start Prime95 or Quake II demo loop and it jumps to 45 at standard speed or 60-65 in two minutes overclocked. The heat sink never feels very warm. I thought maybe the HSF wasn't sitting just right, but it looks fine. Used AS paste. Very strange. R

Ah, you are overclocking. Didn't realize that. Are you boosting the cpu voltage? If so, then I would assume those temps are normal. If you want better cooling, maybe an aftermarket HSF combo might help lower the temps.

 

[RickH]

But the same CPU/HFS/voltage was used in a BX chipset MB for 2 years without these extreem temps. And the idle temps are "normal".

 

[Wiz]

My cusl2-C runs overclocked all the time but temps running seti@home (100% cpu utilization) never went above 50C running a P3 700e @ 933 and now I'm running a cel 1.1A @ about 1.45ghz and temps are still below 50C while running seti. 65C is too high, I ran the 1009 bios a long time and it didn't effect my cpu temp reading.

I did have issues with getting the HSF on there real good - if it's off by the slightest amount the temp will spike up. If you haven't already I would double / triple check the hsf mounting. Once I had it 180 degrees bass ackwards and got temps like you are reporting. That was an alpha hsf too.

 

[oldfart]

If you haven't already I would double / triple check the hsf mounting.

A nice THIN layer of AS??

 

[RickH]

The HSF was installed with the MB out of the case. I checked to see if it was off 180 degrees. Nope. AS on the HSF, wipe it off, then a small amount on the core and attach the HSF. Maybe the thermal diode is wrong. R