Adding an extra 16GB to my 2008 Mac Pro

I while back I wrote about my eBay purchase of a 2008 Mac Pro. Since it only came with 4GB, I purchased an additional 16GB from a vendor on eBay to bump it up to 20GB.

The 2008 Mac Pro (and I think more recent models up to but not including the current trashcan design) has two slide out trays that each take 4 sticks of 800 MHz DDR2 EEC DIMMs, up to a max of 64GB. Here’s the inside layout – the modular and easy access to every part of the insides of the machine still amazes me – it’s clear Apple put just as much thought and effort into designing the inside of the Mac Pro as they did the iconic outside. When’s the last time you opened a PC desktop case and were taken back by clean and logical layout of the inside (inside of seeing a rat’s nest of multicolored cables stuffed inside a box):

  • top left: optical drives
  • underneath: 4x 3.5″ slide out drive bays (no cables to attach to the drives – just slide out the tray, screw in the drive to the tray, then slide it back in to attach it)
  • center right: 4x PCI-e slots for graphics cards etc (two PCIe x4 slots and two PCIe 2.0 x16 slots)
  • lower left: fans
  • lower center: the 2x Xeon 2.8GHz quad core cpus
  • lower right: the two slide out RAM trays


Sliding out the two trays, here’s the original 4 x 1GB DIMMs spread across the two memory boards – looks like there was the original stock 2x 1GB, and then another 2x 1GBs added:



Here’s the new 4x 4GB sticks ready to insert – note the hefty heatsinks:





And here’s the newly inserted DIMMS along with the original 4. I’m not sure if this is the optimal arrangement as I’ve read you’re supposed to stripe them across the two boards in pairs, so I’ll do a bit more reading and work out if I need to re-arrange them:


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