What things can be done to spruce up an old MacPro 1,1 or 2,1 to make them much faster and more responsive in OS/X Mavericks 10.9.1? I was able to install Mavericks 10.9 on a MacPro 1,1 (2x3.0GHz dual core, wifi, bluetooth, 13GB RAM, 2TB 7200RPM disk, NVidia 8800GT 512MB) using SFOTT: http://forums.macrumors.com/showpost.php?p=18474535&postcount=159 http://oemden.com/?page_id=585 I did the software update to 10.9.1 The MacPro is really slow and sluggish compared to when running 10.6.8 (Snow Leopard). The graphics rendering is slow and sluggish. What sorts of things do people recommend turning off or tweaking to get better performance? I was thinking about replacing the 8800GT with an NVidia GTX-460 card. Is Mountain Lion (10.8.x) snappier and more responsive? I would love to find/buy a nice newer MacPro (4,1 or later) 8 or 12 core machine, but don't think I can afford it. I was thinking about upgrading the CPUs to 2x Intel Xeon x5365 quad core for 8 real cores and more cache (compared to the 4 real cores right now). Anybody got a screaming deal on matched x5365 (or faster that will work with this machine??)? I was also thinking about putting in an SSD for the system disk. Or, should I keep my eyes peeled and try to buy an 8 or 12 core 5,1? I also have a MacPro 2,1 (2xquad Xeon x5365 3.0GHz, 32GB RAM, NVidia QuadroFX 4500, 2TB, FibreChannel, ...) running 10.6.8 that I was thinking about upgrading to Mavericks, but I want to be sure it will be fast and responsive. Otherwise, I was thinking about going to Mountain Lion (10.8.x). Will 10.8.x be faster on this old hardware than 10.9.x? I have an NVidia GTX-660 that I was going to stick in that machine once I get 10.9.x or 10.8.x installed. I know that it is kind of wasteful sticking a PCIe 3.0 card in those machines given that the MacPro 1,1 and 2,1 are only PCIe 1.0. Thanks!