What are the differences between ram?

What is the difference between DDR and DDR2? 
Will old motherboards have problems running DDR2? 
What do the different timings on ram stand for? 
How much performance can you expect to gain from faster ram?
Will you gain more performance with more ram then faster ram? 

Don't bother with rams.  Goats are better.

Unfortunately goats do nothing for my computer.

goatse.exe - the best downloadable goat software for all your computing needs

i lold

The difference between DDR and DDR2 is the pin count. There's 184 pins on DDR and 240 pins on DDR2. DDR2 is also rated to run at higher speeds (average 400 (PC2-6400) MHz on DDR2 compared to 200 (PC-3200) MHz on DDR)

So yes, old motherboards will have a problem running DDR2 :)

I am not 100% sure of what the timings do technically (but you can read about it on wikipedia), but the lower they are the better the performance.

You'll have to do quite a jump in speed for the performance increase to be noticable. On DDR1 200 to 250 MHz is a quite huge jump (on the same timings), and will most likely be noticed.

Also performance increase on more RAM differs. If you  have about 1 gig of RAM now, you won't notice a performance increase in everyday apps, but you'll most likely notice it in games if you upgrade to 2 gigs. ANY kind of computer should have at least 512 megs of RAM, even if it's a work computer.
Recommended for gamers is 2 gigs (a gig is fine too)

ddr is double data rate

>>7
NO ITS DANCE DANCE REVOLUTION YOU DUMBASS

>>8 Hahahahahahaahahahahahaha nearly pissed myself over that, nice one.