12-core Mac Pro - 6 x 4GB vs. 3 x 8GB?

[nanofrog]

Well, glad that we talked about that as I'm constantly looking for a good deal on two 4GB sticks. I think my search is done. Thanks for the heads up!

Hope it saves you some headache, though it means swapping out the OEM memory, increasing costs.

Why exactly do the smaller sticks not need a thermal diode?

They don't draw enougn power would allow them to overheat.

AFAIK the Hynix memory my Pro uses (Apple supplied RAM) has thermal sensors, at least iStat menus reads them. Actually, I thought that RAM that is supposed to work in a Pro requires thermal sensors (reason being the SMC).

I suspect that Apple exceeded DDR3 spec, but even if the OEM 1 & 2GB sticks do have the diodes, there's something "funky" going on (change in pin-outs or more likely, range I suspect), as they won't mix with 4GB sticks, even though they're all UDIMM (OWC makes a note of this, though there's no detail to it at all).

Thinking in terms of range, the DIMM socket used to determine the range in the SMC code won't match everything that's installed (results in an error), as it's capacity specific; that is range/profile A for 1 or 2GB UDIMM, B for 4GB UDIMM, and C for 8GB RDIMM for example.

Hope this makes sense.