QOTD: What's going on with my Mac Pro RAM?

[xv]

I've been blowing more and more dust out of my Mac Pro over the last few days. The worst problem I've had is getting it to recognize all its installed RAM. From a quick Google, it seems like this is may be a common problem for this class of machine. Unfortunately, I don't remember how much RAM this computer last had, or when or where I bought the

Comments

[xv]

Another thing that occurs to me, and slightly worries me.

When looking at the cards "like fruit" -- I noticed that even the area around the Micron chips looked a little wonky, like perhaps it had been "cooked" -- presumably by the heat bubbling off the lower riser.

I notice with great interest that the riser design was one of the first major things they changed in the Mac Pro line after my Gen 1 unit. The change they made was to flip the orientation of the upper riser, so it would form a RAM-sandwich with the lower riser.

In my current set up, the Apple chips are now hanging out in the very spot where the Micron chips were. Assuming that I need to use the slots closest to the logic board, then this is the ideal set up, as the most valuable 1gb chips are now on the bottom riser, and the dispensable 512mb chips are on the upper

[ravenofdreams]

You can split the RAM across the risers in a variety of ways and verify your riser boards. (While yes, it is best to keep the RAM as close to the processor as possible on a long-term basis, you can fudge it if you have to.) Also, you may wish to load them all up and try memtest, which is a utility to, as the name suggests, test your memory. It will tell you which specific chips/slots fail.
The other trick would be to look for the Apple Service Diagnostic for your specific model - it's like the Apple Hardware Test that comes on your install discs, but more in-depth. You can probably find them on most torrent sites. (Apple will not give them to you; they're in-house only, but they are damn useful if you can get them.)

[xv]

Incredibly useful information. Thank you for reading and responding. This gives me an idea, I think I might move those 512 sticks further from the logic board on the upper riser. That is, whenever I get to it. And I might plug in the old "bad" sticks too to see if I can test them using those apps. I thought I would need a separate testing unit, but of course the computer should be an ideal testing platform.