I'll be flashing to 5,1 and upgrading a Mac Pro 4,1 from eBay as soon as it arrives. I know thing one is to max out the memory but I'm wondering if it's at all worthwhile to try to do the 3 channel RAM thing. Would any speed boost realized by 3 identical sticks in slots 1 thru 3 be significant, or would more RAM in the 4th slot confer more speed still? Is this even a compelling speed boost or will it get lost in the sauce of other upgrade variables? Regarding disk storage, it has two (a 640GB and 1TB) HDs already installed, neither of which I will really feel safe with even if they test out OK with TechTool Pro. I'm thinking of adding an SSD boot drive and the fastest 1TB SATA I can afford. Will the on board controller be able to utilize a 6Gb/s SATA? Should I go for a PCIe card like the OWC Accelsior for either boot or work drive? Is there a fast HDD boot drive solution which would be as good in terms of speed as an SSD? Do SSDs have a high failure rate in Mac Pros? Thanks for any insights.