<< huh? I've filled each slot in my Tyan duallie boards without issue. There are more than 3 "useable" slots, for certain. 760MPX boards will be a different story though -- the 64-bit slots are 66MHz and keyed for 66MHz cards only -- so you won't be able to use a 32-bit card with them. That's a disadvantage in some scenarios. Also, while it was claimed 760MPX would support regular unbuffered DIMMs, I see the ASUS duallie only allows that to 2GB. To go over 2GB, you need Registered modules. I'm wondering if that will be the scenario with all the 760MPX-based boards. >>
Click on the link, it's a MPX board, and it says it supports regular PC2100, but you can only use 2 dimms. If you want to fill up all the dimm slots, you need registered.