I'm looking to add 2x512Mb of PC3200 memory, hopefully in dual channel mode, to my PC. I would also like to keep the existing 2x 256 PC3200 modules (currently in slots A1 and A3) in my machine if possible and have a total of 1.5Gb RAM without any memory underclocking going on. I do not have any documentation about my motherboard, nor can I find whether my PC model number or motherboard model number in any memory advisor. In addition to previous responses on this forum, the only other helpful link I have found is here - http://www.uktsupport.co.uk/advent/pc/t9.htm How can I verify that I am currently running dual channel? Also running the Belarc Advisor quotes my Bus Clock as 200MHz, yet the link above says it is capable of 800 MHz. What should I be doing to make use of this speed, or have I totally misunderstood? Sorry for not being clearer, but I'm more than a little unclear about all this!

As far as I know you can't run different sorts of ram together in dual channel mode. To run 4 modules in dual channel you need 4 identical ram sticks. At least with my Socket939 board that's the way and I think with intel boards it has to be the same! About the speed 200MHz is okay. With intel cpu this rating is counted double and with DDR ram this is again double which makes it 800MHz!

Intel "quad-pumps" the FSB, so 200mhz x 4 = 800FSB. Question to you - do you really need that much RAM? Use one of these programs to identify your motherboard, then go to the manufacturer's website & download the manual. You may wanna consider a BIOS update as well, depending on what's been "fixed" in the updated versions http://www.lavalys.com/products/download.php?pid=1&lang=en&pageid=3 http://www.cpuid.com/cpuz.php Asus A7N8X-X 2500+ Sempron @ 2100mhz 10.5 x 200mhz @ 1.80v 512mb PC3200 Ti4200/8X 128mb WDC 60GB

I believe that with Intel MBs you CAN use different sized pairs of RAM. As jam said, do you need it. Use the link jam provided to DL Everest. This should give you all the info you need. The SPD option in motheboard may tell you the exact brand of memory that is currently in the computer. After you get the MB make and model, DLoad a manual to find out what you can do.