I have 512mb PC2700 DDR RAM for ASUS A7V8X-X motherboard. It works fine. I just bought an additional 512MB PC3200 RAM and put it in the second(and third) slots. It doesn't seem to be recognized. I put it in the first slot and removed the original stick and the PC works. So for some reason, slots 2 and 3 don't work. Is there a setting to be changed? I have never used those 2 slots so I cant imagine them being broken. Both RAM sticks work individually in Slot 1 and none work in Slot 2 or 3. Any ideas?

You should always check your motherboard manual or manufacturer's website before adding RAM. I highly doubt there's anything wrong with your RAM slots....you've exceeded the allowable number of banks. This is from the Asus website: "DDR400 (PC3200), the latest and fastest DDR memory standard, supports bandwidth up to 3.2GB/s to provide enhanced system performance. (Note: PC3200 Max. to 2 banks only; PC2700 Max. to 4 banks only)" http://www.asus.com.tw/products.asp... In other words, if you install PC3200, you can either use one double-sided stick, or two single sided sticks.

Q: As I know, A7V8X-X can support up to PC3200. However, I found one note in user's manual: "PC3200 maximum to 2 banks only and PC2700 maximum to 4 banks only" Could you explain more in detail? A: Simply to say, one single sided DIMM means one bank, one double sided DIMM means two banks, two single sided DIMMs means two banks, etc. Hence, e.g. you can install one pcs double sided PC3200 or two PCs single sided PC3200. Q: Does A7V8X-X support ECC memory? A: No, A7V8X-X only supports non-ECC unbuffered DDR SDRAM. Q: When I install 3 DDR333 (PC2700) DIMMs on A7V8X-X, the system becomes unstable. But if I remove one, the system works properly. Why? A: Due to the chipset limitation, A7V8X-X supports 4 banks DDR333 max. It means you may have to use 3 single-bank DDR333 DIMMs or 2 single-bank with one dual-bank DDR333 DIMMs max. Please contact with the memory manufacturer to confirm with the memory bank Spec. In addition, please use DDR333 memory in the QVL section on ASUS web or A7V8X-X manual. Q: The DDR 400 memory can only run at 333MHz when I use AMD 333MHz FSB CPU on A7V8X-X. Why? A: Due to the chipset limitation, if you use 333MHz FSB CPU the system memory will only supports DDR 333 only. Thus, DDR 400 memory will be downgraded to 333MHz, meanwhile DDR 200/266 memory will be overclocked to 333MHz. This may cause system to be unstable. Q: Does A7V8X-X support DDR400 (PC3200) memory? A: Yes, A7V8X-X can support DDR400 (PC3200) memory. Due to the chipset limitation, it can only support 2 banks DDR400, and DDR400 memory only work with 200/266MHz FSB CPU. http://support.asus.com/faq/faq.aspx