what i meant was that if you already had 256MB of DDR memory you would get a small increase in performance in games if you added another 256MB with a total of 512MB. it would not double the speed of your games. 3D game performance is related to the video card hardware.
ram quality and type DOES increase gaming/ application performance. if you had 256MB pc2100 and replaced it with similar quality 256MB pc3700 that would definately speed up your system. the memory latency effects the ram the most, that is the reason some memory is better than others.
when people refer to quality of the memory that is usually what they are talking about, this is found by looking at the memory timings. "CAS latency 2, 4-way bank interleave, 1T command,
RAS & RAS to CAS delay & all the other stuff to minimal latency"
Syphanx i think he gave you pc3200 and your motherboard has underclocked the DDR400 down automatically to DDR333. you are using mixed memory types.