Legion Hardware runs a series of test benchmarks using differeny amounts of RAM, both single and dual channel.  See what the tests say about the effect of gobs ‘o RAM on your Frames Per Second and load times.
“Given we now know 1GB of memory is the sweet spot, how much faster is 1GB than 512MB or even 256MB in today’s games? There are still a huge amount of gamers out there fragging away with just 512MB of memory. Of course games such as Far Cry, UT2004 and many others will work quite well with just 512MB of memory. Therefore, it will be interesting to see if benchmarking with these games will show significant improvements favoring 1GB when compared to 512MB. Quite a number of readers also question the performance of dual-channel memory configurations.”

Here are some more Memory articles from around the web:

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