I'm finding a ton of DDR2 667 512MB dimms on ebay, but they are all 1RX8, while the dimms I pulled from the X2 are 1RX16. Does it make a difference?
if the clock speed is the same it should work, I think the 1RX8 and 1RX16 has to do with the size of each single chip on the stick.My Multicart labels for sale here:
My Arcade stuff
It's the "RANKING" ie how many chips to make up the memory (1/2 rows, single sided/double sided) - in the servers we use at work they recommend you don't mix ranking in a bank.
I've upgraded both my X2's and my X using bog standard PC memory without any issues (pity I cant say the same for my Naomi net-Dimms) by ensuring they were matched pairs.
For one X2 I had a pair of 2Gb sticks I took out of my PC when I upgraded to a pair of 8Gb ones and they work fine. the other I used the stick I took from the first X2 - worked fine too (but has less ram in than the other).
The X I had to scrounge some old ram from work as I didn't have a pair the right spec, again I swapped the original ram out for a matched pair of 1Gb sticks.
Got a pair of 1RX8 and they seem to work fine.