I am thinking of add a 5850 so that I can crossfire it. I have a few issues with this though.
1) I have the OCZ ModXStream Pro 600W PSU. Will this be enough power to power the two cards?
CPU: Intel i7-860 2.8ghz
RAM: 4x2GB DDR3
HDD: 640GB 7200RPM
ROM: DVD RW
Graphics: ATI 5850
2) I threw away all my boxes including the motherboard and PSU boxes. I only have 1 x 6-Pin, 1 x 6+2-Pin and 2x SATA cables now. If I add a second card, I'm going to need a second set of 1 x 6-Pin, 1 x 6+2-Pin cables to power it right? How does this work because A) I don't have a second set of cable B) the PSU doesn't look like there's slots for another set. How do people usually solve this power cable issue?
3) Since I threw away the boxes, the crossfire bridge is gone as well. Will this XFX branded crossfire bridge work for my Sapphire 5850 card and I'm not sure the brand of second card yet?
The crossfire bridge makes no difference at all so long as it is attached to both cards.
As for crossfire on that PSU, it is possible but I wouldn't if I were you.
Will it boot ? Yes it will. On full load you will be pushing the limits of the PSU and you may destroy all you have. That would be bad.