Unstable system, underclocking = stable. What's wrong?

[tk149]

I built a system for my parents. It was pretty unstable, until I underclocked it to 100MHz.

Soyo Dragon Ultra Lite (KT333)
Onboard sound/LAN
256MB Kingston ValueRAM PC2700
Athlon XP1900+ w/Retail HSF
Matrox Millenium (4MB) PCI Video
Maxtor 40GB 7200RPM HD
Yamaha CDRW4416EZ
Windows98SE w/latest patches and drivers

I ran MemTest86 on it several times. It seemed to run fine sometimes (when it was cold inside the room) and gave errors (when it was hot). At least, that's what it seemed like. So...

At first I thought it was just overheating because of the retail HSF, so I set the BIOS temperature alarm at 60 degrees Celsius, and the included HW monitor alarm at 60 too. It has never set off a warning. I've never seen the temperature go above 55.

I initially just used the thermal pad that came with the CPU, but later I reinstalled the CPU/HSF with thermal grease since I thought it might be overheating, but that didn't help.

I FDISKed and reformatted the originial hard drive (an old 4 GB), and later put in the new Maxtor as the primary drive.

After months of not figuring out what was wrong, I finally underclocked the darn thing, and it's been completely stable ever since. What the heck could be wrong with it?

BTW, can anyone recommend a quiet HSF for this processor? No overclocking involved.

EDIT: Antec 330W Trupower
EDIT2: All parts purchased from Newegg. Memory Timings by SPD.

 

[microAmp]

Have you tried updating the BIOS?

Also, what are your memory timings? Set to agressive or relaxed timings, SPD?

 

[mechBgon]

Heatsink on the right way? If it's reversed, there is one big disaster waiting to happen. I believe your board has the raised, solid-plastic end of the CPU socket oriented towards the memory slots, right? And the stepped end of your heatsink's base should be oriented towards the memory slots too, so it provides the necessary clearance.

If your RAM is set to run at PC2700 speeds then I would also recommend adjusting your CPU:RAM ratio to 1:1 and see if it's suddenly content with the CPU at its rated speed.

 

[Rav3n]

Another possibility is if you bought the processor at a comp show, or from a sketchy dealer... in this case,the processor could have been marked incorrectly. If this is the case, you might have a processor you THINK should run at one speed, but it really shouldnt. The processor could just plain old be defective.

One thing you might want to try, change the multiplier on the processor to a higher speed and increase the voltage, while maintaining the 1-- mhz bus... just to try I guess.

 

[WarCon]

Did they use frag tape to mount the Northbridge fan? Wonder if its overheating.

I am also going to assume you cleaned the pad off the heatsink thoroughly before using thermal compound? Slk-800 with a nice quiet 80mm fan like a panaflo might work (but might be more money than you wanna spend).

 

[xSauronx]

Originally posted by: mechBgon
Heatsink on the right way? If it's reversed, there is one big disaster waiting to happen. I believe your board has the raised, solid-plastic end of the CPU socket oriented towards the memory slots, right? And the stepped end of your heatsink's base should be oriented towards the memory slots too, so it provides the necessary clearance.

If your RAM is set to run at PC2700 speeds then I would also recommend adjusting your CPU:RAM ratio to 1:1 and see if it's suddenly content with the CPU at its rated speed.

this is what my bro did one time, heatsink on the wrong way, system wouldnt remain stable more than 10 minutes
thats all it was, fixed the heatsink and it runs like a champ, easy thing to mix up, but important

 

[tk149]

Originally posted by: motoamd
Have you tried updating the BIOS?

Also, what are your memory timings? Set to agressive or relaxed timings, SPD?

I will have to try to flash the BIOS next weekend. All the BIOS settings are default by SPD.

 

[tk149]

Originally posted by: mechBgon
Heatsink on the right way? If it's reversed, there is one big disaster waiting to happen. I believe your board has the raised, solid-plastic end of the CPU socket oriented towards the memory slots, right? And the stepped end of your heatsink's base should be oriented towards the memory slots too, so it provides the necessary clearance.

If your RAM is set to run at PC2700 speeds then I would also recommend adjusting your CPU:RAM ratio to 1:1 and see if it's suddenly content with the CPU at its rated speed.

The heatsink is on correctly. This is my fourth or fifth system build (not to mention the rebuilds ), and this is the only one having problems. I will try the RAM adjustment next weekend. Thanks!

 

[tk149]

Originally posted by: Rav3n
Another possibility is if you bought the processor at a comp show, or from a sketchy dealer... in this case,the processor could have been marked incorrectly. If this is the case, you might have a processor you THINK should run at one speed, but it really shouldnt. The processor could just plain old be defective.

One thing you might want to try, change the multiplier on the processor to a higher speed and increase the voltage, while maintaining the 1-- mhz bus... just to try I guess.

All parts from Newegg. Although I think I might have gotten the memory direct from Viking?

EDIT: All parts purchased new from Newegg.

 

[tk149]

Originally posted by: WarCon
Did they use frag tape to mount the Northbridge fan? Wonder if its overheating.

I am also going to assume you cleaned the pad off the heatsink thoroughly before using thermal compound? Slk-800 with a nice quiet 80mm fan like a panaflo might work (but might be more money than you wanna spend).

I'll have to look at the chipset fan, although I thought the KT333 ran cool enough. I cleaned off the HSF according to the instruction on Arctic Silver's website (xylene based solvent and tape head cleaner). Thanks.