As stated one of my 5850's died and I have the choice of 1) getting another 5850 to replace the dead one. 2) getting 2X 6850's and selling the working 5850. 3) any other options that you guys come up with I am asking because looking at some of the rives has the 5850 above the 6850 and some has the 6850 out in front and it has me all confused.
Budget: $300-350 total (that would be 1X or 2X cards) CDN before rebates.
PSU: Corsair Professional Series HX750W
CPU: Phenom II 965
MB: Asus Crosshair IV Formula
RAM 8G G-skill.
Is your 5850 still under warranty? They haven't been released longer than most warranties, but you never know.
Moving from a 5850 setup to a 6850 setup isn't going to be worth it. Depending on the game, resolution, and settings these two crossfire setups trade wins. There are some things that make the 6850 attractive (power consumption and only requiring 1 6-pin pci-e connector per card) but if you already have 1 5850 stick with it. Otherwise you'll spend that extra money for no significant performance game (and potentially a performance loss).
There are some smokin good deals on 5850s- some as low as 130ish after rebates (in the US). Check out 6850 crossfire reviews, too- they should include direct comparisons to 5850 crossfire setups. The time investment is worth it to better understand how they stack up. Cheers!
As far as i understand the 6850 is much better at tessallation.
So given the opportunity you'd be better off upgrading to the 6xxx series.
The HD6850 is a slower card than the HD5850. Tessellation and crossfire scaling are improved in the new series but even for both of those it is basically just enough for the HD6850 to catch up with the HD5850. Here is some benchmarks for the tessellation heavy Unigine Heaven benchmark:
The HD5850 still manages to squeak out a small win over the HD6850.