Hello all! new to the macrumours scene, although have used a fair amount of articles in my research over the past several months. Started with a Mac Pro 1,1 with twin 3GHz dual cores, upgraded RAM, card to an Apple 5770. Currently in the process of upgrading the processors to the popular x5355 xeons. Went with a pair of SLAEG models, after reading other stepping has been causing issues from case to case with the fans kicking to max RPM etc. Have another 1,1 that ill be modding soon, potentially to 5365s if budget allows. First question: does the 5365 really have enough of a headup on the 55's to warrant the price change (got the 55's for $40 a pair, looking at 75-100 for a pair of 65's)? Also, thinking about just buy/selling my current projects to nab a 4,1 or 5,1 model to be my mainstay. For going all out, i'm looking at the entry level 8core model for either gen, x8 2.26, or 2.4 Ghz versions respectively (at least figured if i start with a dual proc tray and can upgrade after firmware reflash). Since anything processor/storage/memory/GPU will be swapped/boosted, is there anything drasticly different enough with the logic board or power supply, bus speeds, total available PCIe lanes, etc between the 4,1 and 5,1 models? As far as the upgrade to the machine, which will be running multiple SSDs/PCIe SSDs, OSX for everything personal and some use of pro tools for hobby music creation and light photo editing, Windows in Bootcamp to run home automation system compostion software and for games. Looking at moving to a Radeon 280x to fit both bills, but as the far as the processors.......SUCH a HEADACHE! Options currently stand at x5650, x5670, x5675, and x5690. Obviously the speeds increase, cache seems the same@12MB...i just would like to know if there are any real world benefits besides a bump in clock speed to justify spending 500 vs 100 for a pair of x6 xeons? particularly for my applications?? I appreciate any and all input from anyone just some discussion to help me think it out!