you'd be surprised at how big of difference there is between say 2-2-2-5 latency RAM and 2-3-3-5 Latency (which I don't think that specific combo 2-3-3-5 exists I'm just using an example right now) but anywho, those two numbers there in the middle, the ras to cas and ras precharge, have a significant effect on the amount of memory that's transferred through. If you happen to have 2-2-2-5 RAM, run memtest and see what it registers you mb/sec as, then change it to 2-3-3-5 and you'll notice a significant decrease. All these timings are of course in terms of nanoseconds, but they do add up by the time you notice anything.
If you have high latency RAM then 512 probably would suit your needs, and a lot of people would agree that's a good amount for most applications. And it is really. You only need 1gb of RAM high performance or not, if you game and/or do multitasking and running things like CAD then yeah you are definitely needing atleast 1gb of good RAM and even that I think would serve your needs. If you run Freemem it shows you how much is being used. Use that program to see how low your current RAM levels are and see how much you need to upgrade.
The latency number that can be loosened up the most is the last number the Cycle Time(Tras) this number is generally loosened when overclocking your RAM, otherwise you want it as tight as possible and generally even with valueRAM you can tighten that timing up. I have kingston valueRAM rated at 3-3-3-8 but it runs 2.5-3-3-6 no problems. The first number is the Cas Latency and generally that's where you definitely know between valueRAM and high performance.
ValueRAM will be 3 although if you want to pay a little bit more they generally have an option between CL2.5 or CL3 which is saying Cas latency 2.5 or Cas latency 3. I don't know if there's valueRAM that has a CL of 2 or if that's strickly high performance RAM, although since I know you can on some sticks and perhaps with a little luck hit 2.5 on a rated 3 maybe you can hit 2 on a rated 2.5
NvidiaFanBoy - Just ignore anyone who gives you crap don't go along with it.
Everyone Giving Fan Boy Crap - Stop it as people are trying to learn here, regardless of what your opinion is of somebody take it to a private conversation not in the threads. If he posts incorrect information that could potentially lead to someone new learning something wrong, rest assured I or somebody else will see it. Try to correct without being offensive also.