Weird stability/temperature problem with Abit KN8-SLI

Helios · Post by **Helios** » Sat Sep 09, 2006 6:06 am

Computer:
Abit KN8-SLI Bios 1.9
AMD 64 X2 4600+
4x512 Corsair 3200XL Memory
XFX Geforce 7900GT with Zalman VF900-CU
2 x WD Raptors in RAID0
1 x Samsung P120S
Creative Audigy 2
Thermalright XP-120 with Papst 120mm fan @ 1200 rpm
Seasonic SuperTornado 400W (450W peak)
Lian Li PC70 Case modded with Papst 120mm fans

Just bought and build my new computer and I am experiencing a very weird problem with it. The computer is completely stock running Windows XP on the latest bios and drivers.

The problem is that whenever I run any full load stability testing programs (2xPrime 95 large FFTs torture test or SuperPI 32M) the programs can only run 10-15 minutes before the processor temperatures reaches 80C and the programs fail. The idle temperature is about 30C, I am measuring
temperatures with both Speedfan and Abit EQ. Bios idle-temperatures and voltages are close to the same as SpeedFan.

I have reseated the processor and XP-120 four times (using arcic silver 5) and the stock 4600+ cooler (the heatpipe one) twice which haven't helped. I've flashed CMOS, reinstalled windows twice, ran the computer with a minimal number of components to ensure it is not the PSU, checked all wires and caps on the motherboard, put fans on the passive PWN cooler, installed all AMD dual core drivers, and checked for shorts. I also ran the latest MemTest 86+ on the ram without any problems.

The temperature issue is very weird in that under full load the processor stabilizes at about 45C for 5-10 minutes and then suddenly ramps up to 70-80C, with both the core and pwn temperature following it. I know the passive mother board cooler and cpu cooler are making contact since they
become too hot to touch at full load. The computer is also completely stable at idle in Windows, no BSODs or freezes.

I also know the XP-120, PSU and memory is not faulty since they come from my old computer which ran an IC7-G with a 3ghz P4 for several years with full stability under max load for several hours.

My idle temperatures according to SpeedFan:
PWN: 36C
System: 35C
CPU: 31C
CPU Core: 31C
Ambient: 30C
Samsung HD: 31C
Raptors: 34C
7900GT: 40C

Stock Vcore (1.35V), 2.7V DDR Ram, all other psu voltages within +- 5% (not affected by full load).
Ram running at DDR400 Dual Channel 2-2-2-7 2T.

Has anyone here experienced anything similar or is it RMA time?

jharne · Post by **jharne** » Sat Sep 09, 2006 2:22 pm

"I know the passive mother board cooler and cpu cooler are making contact since they become too hot to touch at full load."

Pretty sure they shouldn't be touching. What orientation do you have the Xp-120?

Helios · Post by **Helios** » Sat Sep 09, 2006 2:40 pm

By making contact I meant contact between the coolers and the chips.

I have tried the xp-120 and stock cooler in both possible orientations.

jharne wrote:"I know the passive mother board cooler and cpu cooler are making contact since they become too hot to touch at full load."

Pretty sure they shouldn't be touching. What orientation do you have the Xp-120?

diver · Post by **diver** » Sun Sep 10, 2006 6:32 am

A few xp-120's have been known to have a warped contact area. I would try mounting the stock heatsink for a test. If the problem goes away, then you know there is something wrong with the xp-120.