Mixing FPM and EDO Ram?

[mac2geezer]

For the Ram gurus here, a question. What happens if you mix FPM and EDO Ram in an 8600/9600? Machine gets flakey, won't boot at all, smoke and flames, or?? Also, I just picked up a few sticks that reportedly were pulls from an 8600/300, but according to the Chipmunk site and the Mitsubishi chip markings, one stick is 3.3v. Someone on this forum once said that a 3.3v stick in an 8600 will cause smoke...that's for sure? I'm loathe to experiment.

Thanks in advance for any clarification, insight.

 

[johnklos]

For the Ram gurus here, a question. What happens if you mix FPM and EDO Ram in an 8600/9600? Machine gets flakey, won't boot at all, smoke and flames, or?? Also, I just picked up a few sticks that reportedly were pulls from an 8600/300, but according to the Chipmunk site and the Mitsubishi chip markings, one stick is 3.3v. Someone on this forum once said that a 3.3v stick in an 8600 will cause smoke...that's for sure? I'm loathe to experiment.

It's all about timing. DIMMs give information about themselves to the motherboard, and if a pair of DIMMs do not match, the timing of one might be used for both, and if the second can't handle the speed, the system will be unstable. Most of the time new DIMMs will exceed the best timing of the system so it won't matter, but if you can make sure that FPM and EDO are in pairs, it'll be fine.

Some 3.3 volt chips don't care about 3.3 or 5 volt, but you can't ever count on that. On the other hand, 3.3 volt DIMMs should have a slightly different keying. Line it up along the pins to another DIMM and look to see if the notches match. If the DIMM can physically fit in a 5 volt slot, it can handle 5 volts.

 

[mac2geezer]

Thanks for the info. Two of the sticks I got are 64MB, 5v, FPM, 60ns, as far as I can tell. After installing those two, in A4/B4 slots, the 9600 gets most of the way through the boot, then just hangs every time. I pulled them and installed a couple of 16MB FPM sticks I had lying around and the 9600 boots fine, so not sure what's wrong with the first pair.