The Dell guys are WRONG! Especially if you are trying to take advantage of the 800 MHz front side bus on Intel's 875 processor with DDR. Performance suffers by an average of 25% should different sized memory modules be used.
http://www.officemax.com/max/soluti...nsylvania&pageNum=5&size=L&BV_UseBVCookie=yes all suggestions are too complicated.. just check you frendly office max store 512RAM DDR $70
i third the recommendation for crucial. not always the absolute best price, but very very reliable memory and fast free shipping. look for discounts on www.anandtech.com in the hot deals forum. when there is a sale, www.mushkin.com is also good.
Well, I decided to buy some cheaper memory from Circuit City. No, it didn't work. System kept crashing. Returned it and bought Crucial memory (only $10 more). Flawless operation. Also, I have tried running a single 512mb chipset alone, and in conjunction with my original 256mb chipset. No difference in performance either way. It DOES matter which bank I put them in though. Jay