400 or 533 fsb

I have an old Dell Dimension. I want to upgrade the RAM. How do I tell if I have 400 or 533 fsb? I assume that somehow I can get the computer to tell me what it is.

 

http://www.crucial.com/systemscanner/
They sell quality memory but you can use the info to shop elsewhere if you wish.

 

It really does not matter. The RAM will toggle down to meet the bus speed. That said, I agree to use the Crucial RAM wizard. Note that almost all RAM makers and many retailers (like NewEgg) also have RAM wizards.

 

OK. I ran the Crucial tool. Apparently I need 2x128 RAM. I am good with that. Crucial is out of stock; so is Newegg. Went to some other sites that Google found (some looked kind of dodgy)and either nobody makes this anymore, or it will cost me 150$ or so. For that kind of money I may as well buy a machine. (I'd prefer a Mac but probably can't afford it, so it will probably be a rebuilt PC with windows 7). Before I give up on the RAM, can anyone here suggest a place to buy what I need at a reasonable price? I figure if nobody here knows then the answer does not exist.

 

Ackkk! $150?! Ya, get a new machine as 256MB will not improve performance much unless you only have 256MB or less right now. I'd personally go for the W7 machine.