rdram in pairs?

I know nothing about rambus, so I have a simple question. A friend of mine has a Dell that had 128 mb rdram and wanted to add another 256 mb. He bought a 256 mb module and couldn't get it to work so he called Dell. They said that rdram only works in pairs of the same size so he would have to buy 2 128 mb sticks. He did this and it worked. Now I have another friend who has 2 128 mb sticks installed and wants to add another 256 megs. Will he need 2 128 mg sticks also or can he get one 256 mb stick?

You do need to install rdram in pairs. You must also have terminators in empty sockets. Just one more reason to steer clear of rdram systems.

see http://www.powerspec.com/support/tec...upgrading.html

Hope this helps

It depends on the chipset. The 820 can take them singly, since there is only a single Rambus channel. The 840 (dual PIII) and 850 (P4) have dual Rambus channels, and thus require them in pairs. All three chipsets require continuity modules in any empty slots.