First thing to do is pin down exactly which AMD 2000+xp you have. Run this [link|http://www.amd.com/us-en/assets/content_type/utilities/cpuinfo.exe|CPUInfo] little program from AMD. It pops up a simple window with a bunch of information about your CPU. The one I'm interested in is the Family.Model.Step number, which should be something like 68x or 66x. If it's a model 6 then it's supposed to get 1.75 V, if it's a model 8 then it's supposed to get 1.65 V or 1.60 V acording to some other critera I don't know.

Note that the speed given by CPUInfo may be wrong, it's off by 100 Mhz on my machine. It's a real cheesy program, but it reads the model number off the chip and thats what we want to know here.

The "Autodetect" bios settings (which I try to stick to, because I'm not interested in overclocking) gives me a choice for processor speed: 1250mHz or 1667mHz. Why is this, exactly? The 2000 + processor doesn't actually run at 2000mHz, I know that much, but I'm not sure which of those is the proper setting. I do know that currently if I set it to 1667 the computer reboots endlessly, so 1250 is the "workable" one.

The 2000+xp is supposed to run at 1667 Mhz, or a bus speed of 133 and a multiplier of 12.5. Of course 133 * 12.5 is actually a bit less then 1667 but these things are fudged slightly.

As for why it asks you which, I think it's because the motherboard can't tell from the CPU if it's a 100 or 133 bus speed chip but it knows that it's a 12.5 multiplier chip.

The bus speed defaults to 133 when the cpu is set to 1667, and 100 when set to 1250. I have no idea why, since when the Athlon 1000 was installed it was always at 133. I don't have one of those new 266 boards, and I don't have any of that super-RAM either, but I do have RAM that runs at 133. Why would the board scale back to 100, ever?

The reason it runs at either 1667 or 1250 is that the multiplier is locked, so it can run at either 133*12.5 or 100*12.5 those are the only (legal) choices. On most motherboards you would set the bus speed but yours does it the other way around.

Memory speed and bus speed should be independent of each other in all the resonably new motherboards. It's quite possible that your memory is still running at 133 even if your bus is running at 100.

What kind of CPU temperatures should I be aiming for? I know 80 celsius is too much (geez Jay <grin>) and I know a lot of hardware monitors start to warn you at around 60... but what should I aim for with all the heat sinks and fans and stuff? What's the optimal heat level for one of these AMD processor thingies? With the case off, the processor tends to average 50-51, this goes up when playing a graphics-intensive or computation-intensive game (Morrowind and Civ III respectively).

Your chip is actually rated for anything up to 90 degrees centigrade. But I would consider anything over 60 when the system is sitting idle as too high, and I would like to keep in under 80 even when pushed. If you can keep it under 60 all the time your doing fine.

I spent a few days untangling this information myself when I put my 2200+xp in.

Jay