I've got two Hiviewell PC3200 DDR 512 MB memory sticks at 400 MHZ and I tried using them both on an old motherboard, the AsRock K7VT4A Pro. The problem is, only one stick works....and surprisingly it does so in the DDR2 slot. Now the puzzle is why does the other DDR slot doesn't accept my stick? When I boot using only the DDR slot I get that annoying beeping regardeless of which memory stick I use, so the problem isn't with them. Both sticks are good and work, tested on another PC.
DDR and DDR2 have the same amount of pins, just different notchs to prevent you from swapping the two.
Look at the contacts on the ram, see a little notch?
Now compare it to the notch on the RAM socket.
Umm....the label on the memory sticks says clearly PC3200 DDR 512 MB so I implied they are DDR 1. Anyway, the motherboard memory slots have the same construction.
The slots are the same, I tried each memory stick in each slot. The top one is labeled DDR 1 and didn't work with any stick and the one under it is labeled DDR 2. It's weird that Windows XP only sees 512 MB RAM when I have both memories in, but when I use a hardware detection software it correctly registers 1024 MB RAM. Could this be a motherboard hardware problem?
Solved, I set the DRAM frequency in BIOS to DDR400 (200MHZ) and Enabled Flexibility Option. Says it allows better tolerance for memory compatibility. Anyway now I've got the 1024 MB RAM in Windows too. Mods can close the thread now, hope it helps people with same problem.