I recently got a Quadra 630 into which I've put a 50 MHz m68040 (underclocked the motherboard to 25 MHz, then put in a QuadDoubler), a 160 gig hard drive (I was wrong - there is no 128 gig limit on these machines), and a 128 meg SIMM which makes the total 132 megs.
In certain places on the Internet I've read that the two SIMM slot version of this motherboard (631, perhaps?) you can install 192 megs total - one 128 meg SIMM and one 64 meg SIMM, so long as the 64 meg SIMM is single banked. Instead of looking for 64 meg SIMMs which are suitable, I was just planning to use a second 128 meg SIMM.
I was wondering if anyone has more than 128 (132) megs of memory in their Quadra / Performa 630-640, and if so, did you have any issues with the SIMM in the second slot?
The 72 pin SIMM socket still hasn't come in the mail, so I figured I'd do some research while I'm waiting.