why would quad-macpro use diff ram than octomac

[bearbo]

http://docs.info.apple.com/article.html?artnum=305352
why would there be such distinction?

With the release of Mac Pro (8-core) computers, Apple has qualified additional memory and hard drive options. Apple memory and hard drive kits designed for Mac Pro (8-core) computers are compatible with all Mac Pro computers (quad-core or 8-core).

Important: Mac Pro memory and hard drive kits designed for quad-core Mac Pro computers only are not qualified for use with a Mac Pro (8-core) computers.

Apple kits compatible with all Mac Pro computers (quad-core and 8-core)

Part Number and description
MA985, 1GB 667MHz DDR2 FB DIMM ECC - 2x512MB
MA986, 2GB 667MHz DDR2 FB DIMM ECC - 2x1GB
MA987, 4GB 667MHz DDR2 FB DIMM ECC - 2x2GB
MA988, 500GB Serial ATA 3Gb/s Hard Drive for Mac pro
MA989, 750GB Serial ATA 3Gb/s Hard Drive for Mac pro

Apple kits compatible only with quad-core Mac Pro computers

Part Number and description

MA684, 1GB 667MHz DDR2 FB DIMM ECC - 2x512MB
MA685, 2GB 667MHz DDR2 FB DIMM ECC - 2x1GB
MA833, 4GB 667MHz DDR2 FB DIMM ECC - 2x2GB
MA690, 500GB Serial ATA 3Gb/s Hard Drive for Mac pro
MA851, 750GB Serial ATA 3Gb/s Hard Drive for Mac pro

 

[Jiddick ExRex]

I will grant you that it's weird. Perhaps it's a way to compete against the ultra low prices of FB-Dimms that have emerged the past month, so that Apple will get a little more dough in their pockets?

 

[Eraserhead]

This is really strange, especially as it appears to be identically spec'd.

 

[tyr2]

Different heat sinks/spreaders perhaps?

 

[osx-linux]

My only guess would be the heat. The mactopus certainly will get hotter than the quad.

 

[iMeowbot]

Well, as they say there, "qualified", as in the older stuff might possibly work but hasn't been tested. If there have been any revisions to the parts in the months since the first models came out, they may simply have wanted to skip testing of the older ones that are probably still in circulation.

 

[Father Jack]

I agree with most .... it is probably heat orientated.