I have a 2010 2.4ghz 8 core Mac Pro. I've bought 32GB ram (4GB x 8) and whenever I put any ram in the 8th slot, OSX won't recognize the 7th & 8th slot. I tested all the sticks, none of them faulty. I reset the PRAM. Tried blowing air into the 8th slot, nothing. I now have slots 1-7 occupied for 28gb ram, but if I put anything in the eighth slot, Mac OSX will only show 24GB because it then won't recognize the ram in the 7th AND 8th slot. Any ideas?