Hi, I have a lot of stability problems lately. So I downclocked my CPU external Frequency from 133 Mhz to 100 Mhz (multiplier 12.5). Now it runs very stabil, but now my CPU runs at 1,2Ghz. And in the past it was running at 1,7 Ghz. What is wrong with my pc? When I set CPU external Frequency at 133 Mhz it blocks or shuts down when i use a more heavy application ? Is it my RAM or my CPU ? I have an Athlon xp 2000+@1,7 Ghz with FSB 133 Mhz. thanks

Oh, by the way: my motherbord is asus A7N8X-X.

There are three variations of the Athlon XP 2000+, Palomino, Tbred, and Thornton. All of them clock default @ 1666MHz (133x12.5) with Vcore 1.6v except the Palomino with 1.75v, have you checked your voltage setting in the BIOS ? What is your amp reading on your PSU's +12v rail and what is the PSU rated maximum wattage ? Do not type anything in this space.

My Vcore setting in bios is 1.75v But I don't know what "PSU's +12v rail and the PSU rated maximum wattage" is. Sorry... But when I only change the CPU external Frequency to 133 it gives problems (but in the past it din't do that). I leave all the other settings the same. Another strange thing: When I put the CPU external Frequency at 133, and I start my pc, he says memory 166 Mhz, BUT when i set it at 100, my it says 200 Mhz at startup. But 133 is Higher then 100, or am I missing something ???

Sounds like either the PSU isn't coping or the CPU is running too warm causing the shutdowns under load. Check out the temps in the BIOS as well as the 3.3v, 5v + 12v rails - should be under 'hardware monitoring'or something similiar. Easier still, get speedfan - http://www.almico.com/speedfan.php - this can tell you the temps and the voltage readings in windows. The reason it says 200MHz when you set it to 100 is that this is 200DDR, 100x2, like if you ran a 133FSB should say 266DDR. You should check to see if the FSB:Mem Ratio is 1:1 and not 2:3 or similar else the mem will run faster than the fsb..ive found this alone can cause problems sometimes on amd setups.

If the BIOS setting for your RAM is "BY SPD" & you have PC2700 (DDR333), the RAM will run at 166MHz regardless of what the CPU FSB setting is. If you want the CPU & RAM to run at the same speed (1:1 ratio), change the setting to "100%" Asus A7N8X-X 1800+ @ 8 x 210MHz 768MB PC3200 Asus A9550 128MB/128-bit WinME/WinXP Pro

CPU External Freq. = 133MHz CPU Frequency Multiple = AUTO System Performance = User Defined CPU Interface = Optimal Memory Frequency = 100% Memory Timing = Optimal FSB Spread Spectrum = Disabled AGP Spread Spectrum = Disabled CPU Vcore Setting = AUTO (or set to MENU, then set CPU Vcore to 1.75v) Graphics Aperture Size = 128MB AGP Frequency = 66MHz Asus A7N8X-X 1800+ @ 8 x 210MHz 768MB PC3200 Asus A9550 128MB/128-bit WinME/WinXP Pro