FSB: how to know what FSB is required

hi all, i'm back with a question:

i've bought a PC a couple of months ago, and i turned out the motherboard was broken. No problem there, cause i still had warranty. The problem actually is the fact that my motherboard (ASUS A8V Deluxe) isn't being made anymore, so i had to pick a new one.

After some comparison i choose the ASUS A8N SLI Premium, but they're being delivered with a 1000MHz FSB and a 2000MHz FSB, apparently.
I have an AMD Athlon64 3700+ 2.2GHz and a 2000MHz bus.

Now my question is this: do i have to pick the 2000MHz FSB of the motherboard, or will the 1000MHz be enough, and why?
i'm not very familiar with computer stuff, it's my first pc i've completely created myself.

i know what the FSB does (internal link between the components of your computer). but i'ld like to know if it is important to have the same FSB as my processor.

thanx in advance,
UnrealEd

[vee_ess]

You must have the same FSB as your processor. The settings will be in the BIOS, most likely in the first menu.

ok thanx, than i will take the 2000MHz.

i have another question now, it's not really related to this topic, but here it is: what does the L1 and L2 cache do on processors? what is best? is there really a difference noticable?

thanx in advance,
UnrealEd

[Dragon]

as i recall, l1 and l2, though i cant remember the amounts, contain a number of registers of DRAM (32 maybe?) which is part of the reason processors are so bloody expensive. in any case, the registers store small amounts of rapidly accessible information for processing, or the result thereof. as with any memory, More is typically better, if you can access it fast enough.

[vee_ess]

In addition to what Dragon mentioned, L1 cache is usually built onto the processor's chip itself and varies according series, and L2 is usually a separate chip on the processor, allowing for varying sizes of L2 cache.

And yes, the difference is usually noticable. Historically, AMD and Intel have sometimes released "new models" which are just old models with more cache.