I recently brought my 2006 mac pro back from the brink of ruin following a hard drive failure (thanks to those who assisted me, btw!) by throwing in an ssd and 16gb of RAM. While going through all of that joy, I perused many of the threads about the 8 core CPU upgrade and they really got me interested in doing that upgrade as well. As a matter of fact, 2 Xeon 5355s are merrily on their way to me as I type this... But now I'm having second thoughts about the CPU upgrade on the grounds that my Pro is functioning so much snappier than it ever has before... most of my work is gigapixel manipulation in Photoshop... I routinely work with .psb files in excess of 3gb. On the other hand, I don't use Final Cut or any of the other programs commonly mentioned on here as being able to really benefit from 8 cores and, furthermore, my current setup is the 2 x 3.0 Ghz Dual Core variety. Installing the 5355s, while it would be fun, would drop my clock speed down to 2.66 Ghz, while adding an additional 4 cores. So, for those with expertise in these areas... will I see a performance bump at all from installing the 5355s or should I just call it good as-is and resell the 5355s? I'd love to do the install, but not at the cost of performance. Thanks in advance!