I am not sure what Asus A7N8X-E shows during POST (long time since I had my A7N8X) but compare the 200MHz (manually set) and the auto setting and see what they say. It could be so that the Asus m/b shows non-DDR speeds...
I also find it a little strange as you can only set it to 200MHz as maximum, that very little overclocking capability (not that it matters so much in this case, but still).
About your 166vs200 question;
Your CPU's speed is determined by 2 things, FSB and multiplier. The FSB is on the motherboard and the multiplier is CPU. So lets say you have 166MHz FSB and a multiplier that is 11 you take 166*11=1826 (1826MHz on the CPU) and then,
1826*3=5478, 5478/2=2739, 2739-300=2436~2400 and BAM an Athlon XP 2400+. Ehhh not that it had something to really with the question, but still that is how you calculate the "+value" on the old Athlon XP (not Barton).
Now if you raise your FSB from 166 to 200 you get a new calculation,
200x11=2200 and then the "+" calculation it will be 3000+.
What you are doing is overclocking, and when you raise from 166 to 200 it is most likely your CPU that is not able to handle the speed change without getting more voltage or better cooling or both. Also you PCI/APG speeds will get higher and your graphics card fail due to not being able to handle an APG bus higher then standard/little more than standard. There are several more factors, IDE controller crapping out due to higher frequency, SATA controller and so on. You should have the option to lock the PCI bus though. That will keep it at a constant level (so that overclocking will not affect SATA, IDE, APG, PCI).
Advise: Do NOT overclock if you are not aware of the risks and are fully aware of what you are doing.
Hope that answers your question (and brings you a little more knowledge for free
). If not, say so and I will cut it down a bit...
