Here’s my problem: I recently bought a barebones system based around an AMD Athlon XP 2700 processor, which is supposed to run at around 2.2Ghz. The processor has a 333Mhz FSB, which means that the clock setting in BIOS should be set at 166. However, if I raise the FSB to 166 the system becomes completely unstable.

It runs very hot (56 idle and near 70 full load), and I get a lot of access violation errors whenever I try to run CPU-intensive programs such as video encoding. When I lower the clock setting to 133, the system runs fine—but the processor reads in the BIOS as a 2100/1.7Ghz. I’d like to be able to use the processor at its full speed. I’m thinking these might be possible causes:.

Overheating—I know the temp is pushing it a bit at 70, but I don’t know if that would cause the access violations.
Bad RAM—the RAM came with the system, and is no-name.
Bad processor—I hope not, but I guess it’s possible.

Any suggestions? Thanks in advance for your help.

Full system specs:

ECS L7S7A2 motherboard; latest BIOS
AMD Athlon XP 2700
512 MB DDR 400
ATI Radeon 9200 8X AGP video card
Soundblaster Audigy LS sound card
Lite-On DVD-R/RW drive
DVD-ROM drive
Windows XP

Your temps are a little high but I am not sure if that alone would cause your problems.

Try testing your memory by using Memtest86
Download Memtest86 from http://www.memtest86.com/
Use it to create a bootable floppy. If you have any errors then you have memory problems.

When I first started I had problems such as yours. Memtest86 showed I had no memory problems. I ended up doing a complete reinstall of Windows XP.

If have an XP2800+ with the following idle temps:
Internal Case: 31 C
CPU socket: 47 C
CPU diode: 58 C
I have no instabilities at all.

open the case and blow a strong house fan in there which should lower the temps which will tell you if you have a temp problem.

When a system works at a low fsb but not a higher fsb and is within the cpu ghz limits (which you are), the problem is usually the motherboard but can also be a heat or power supply problem.

When you say motherboard problem, do you mean the motherboard might be faulty, or that this particular motherboard model can't handle the higher FSB? It's supposedly rated to be able to accomodate the 333 FSB, but I'm not so sure...

I have a new power supply on the way (Seasonic Super Tornado) to replace the cheap-o one that came with the case. Hopefully that will solve some problems too.

Thanks--

Just a follow-up: the new power supply has the temps down quite a bit, but I still get access violation errors when I try to do anything CPU-intensive at 166 fsb. I suppose that means the problem is narrowed down to motherboard or RAM? Is there a good way of testing the motherboard? Thanks...