ok, jaxon, you asked a legitimate question and people started to answer it but then they ran off on a tangent...i'll bring it back on topic and sum it up for you. the people who said win9x (that includes winME) can't "see" or "use" more than 128megs or 256megs of ram are...um...wrong. the marginal rate of benefit does drop significantly after around 256megs (with the exception of photoshop and the like) but that doesn't mean that more can't be used (although the 512meg limit issue i believe is correct). looking back close to two years ago, the "good" systems came with 128megs and the "average" computers had 64megs. at that time, the general opinion was that if you had 128megs you were set. that was also when ram was close to $1.50 per meg. basically, the performance gain might not be worth the money unless you had some spare cash to spend. that, however, doesn't mean that there isn't a performance difference. in my experience (with many systems with various uses), there is a large benefit going from 128megs to 256megs. i'm not just talking about photoshop or unreal tournament, i'm talking about everyday, basic useage. have you ever had a few windows open and you close one, quickly flip to another, and decide to open a folder or internet explorer...and in that time it takes a bit of time for this to happen, the folder you closed is white, the one you just opened doesn't show the icons yet, and you hear the hard drive clicking away...that will not happen like that with another 128megs of ram. now, the person who has 128megs of ram and refuses to buy more will tell you that the 5 seconds he waited for that to happen isn't that long, but i'm telling you that when it takes 1 second with more ram, 5 seconds seems like a long time. this is the "typical useage" performance gain i'm talking about. getting back to a price/performance or cost/benefit analysis, now that 128megs of good quality ram is $50 or so, the added performance is WELL worth it. that's the bottom line, and anyone who tells you different is either not informed or is jealeous because they can't afford more ram...