What if i have 4 memory upgrade slots. I have 2x 256 of pc3200 in channel A Dimm 0 & channel B Dimm 0 ..... If i put in two more 2x 256 pc3200 in the other two slots will it run at 1024 Dual Channel. In another words, will all the memory function together as if i have 1024MBs of Dual PC3200 memory ? Also, in my P4 2.6 w/533FSB the 2x 256 DDR memory PC3200 DDR400 i installed reads as DDR333 in my System Info ? What's the deal with that ? Do in need 800FSB to run it at DDR400 ? Also is it safe to run it the way it is now at DDR333 ? Thank you for your help.

To your 1st question, the answer is yes if you have dual channel memory board. To your 2nd question, the answer is yes. You need to have 800mhz FSB processor for the default to run at DDR400. Some mobo's only go to 320mhz with 533/400, unless you overclock.

...and to your third question, yes, it is safe to run DDR400 at 333.

Thank you very much Shawn, this is a great Tech site everyone is always very helpful. Thanks.

can you just "overclock" your memory in bios to reflect 400 mhz? in my abit nf-7 motherboard, if the cpu/dram ratio is set to 6/6 (i think) and i have a 333 fsb cpu and ddr400 memory...the memory will run in sync with fsb, unless i change that ratio to clock the memory at it's rated speed,no harm done