FSB/Multiplier Question

[Kente]

I have an EPoX 8RDA+ board with an Athlon XP 2000+ processor installed. I just built this system, and at the initial bootup the FSB was set to 100 MHz and the mutliplier was set to some default value (12 i guess). It registers as a 1.2 GHz in windows.

I want to be able to get this most out of this, so is there any real difference in performance if I just change the multiplier to say 16.5 rather than jacking up the FSB to 166 and setting the multiplier to 10?

Also, I'm a bit confused because with this board the bus is supposed to have a max FSB of 333 MHz, while the only options available in BIOS are 100, 133, and 166. And another thing, I have 256 MB of pc2700 ram, which should run at 333 MHz. At bootup it says DDR200.... seems a bit weird.

By the way, it's my first time building a computer so if my questions sound dumb they probably are

 

[RSMemphis]

First of all, a lot of FSB and memory bus values are so-called "double pumped" values, meaning that for 133 MHz actual clock cycles, you actually transmit a bit on the falling and rising edge of the signal, therefore getting "266 MHz" effectively.

That being said, because AMD used to have CPUs with an FSB of 100 MHz (or 200 MHz double pumped), most motherboards still default to that. Actually Durons still need 100 MHz.
Your CPU should normally run at 133 MHz, with 266 MHz being the double pumped value. Then it will also run at the correct speed internally, whatever is appropriate for a 2000+ (I think 1.6 GHz it is)

Your memory CAN run at up to 166 MHz (333 MHz double pumped), put your CPU will most likely not cut that. It's too much of an overclock. The XP 1600+ AGOIA cores were able to handle it, but I think most cores beyond that speed just had to run too fast to be at 166 MHz clock speed.

Cut a long story short - set the jumper to 133 MHz, and you will run your system as intended.

 

[Sunner]

The bus is DDR, so the way they count, 100 MHz = 200 MHz, 133 MHz = 266 MHz, etc.

And the AXP 2000+ uses a 133/266 MHz bus, so if you wanna run it at it's proper settings, set it at a 12.5 muliplier with a 133 MHz bus.

 

[Kente]

Ok that makes sense, thanks guys.