Memory transfering data at 2186.72 MBps is pc2100 DDR SDRAM. What pc pitstop is telling you is that with your configuration--1 Ghz PIII with 640 mb Ram--your transfer rate is lower because you use normal SDRam, and the typical setup for your amount of memory and cpu speed and cpu (PIII) uses DDR. What you have to understand is, that having a PIII right there says about half of the people will use DDR. PIII is at least twice as expensive as the Celeron, depending on what speed and sometimes more, and is the same cpu (comes off same assembly line, made with same material, same size leads in microns, same number of pins and work vice-versa in the same socket with the same chipsets on the same mobos) but they are more because they have a L2 cache that is twice as big (512 kb as apposed to 256). So it is safe to say half the people getting a PIII 1 Ghz (current retail is around $200 me thinks) is just the kind that will want DDR. Now the fact that you have 640 mb ram, well that is way more than anyone needs now (except graphics professionals) and so most people with that much memory are also the type that want DDR... hence why most people with 1 Ghz PIII with 640 mb memory use DDR. It is pretty much the same reason why geeky 24 year-old computer hacks that live in their parent's basement use only UNIX...
Sorry to ramble on like that... I am just trying to explain what is going on here and why. So anyway... your memory is just fine and couldn't be functioning any better. You also don't have any reason to upgrade because (1) you need a new mobo and (2) DDR isn't needed unless you just want it because it is slightly faster. It is faster enough to notice the difference, but it isn't much of a difference because it still is all fast. The pc pitstop should be giving you those results reflecting those with the same configuration using the SAME type of ram... but then again they
are selling ram (as it has been mentioned) anyway.
Edit: It
maybe misleading... but it is still true and that is apparently why they can do it to attract business... or whatever I don't really know. :rolleyes
