3-way Crossfire bad?

It will not be worse but the small gains are not worth the additional investment. If the 2 x HD5770 is not enough, then it is time to upgrade cards.

Generally the 3rd card doesn't scale well so it is a bit of a waste, however, it also depends on your motherboard. If it doesn't support 8x/8x/8x PCIe lanes then yeah the performance will be worse than with just 2 cards.

Right but adding a third card wouldn't decrease performance in any way compared to just 2 cards right?

Depends on your system... you could list the specs and get a proper answer.


http://www.tomshardware.com/reviews/p55-pci-express-sca...

"Looking only at averages, the chart above makes it appear that adding a third card boosts P55 performance by nearly 8%. Yet the fact that it hurts performance in some games and offers no benefit in a few others means that we’d never suggest using the P55 PCH to host a third graphics card in CrossFire or SLI. Moreover, the X58 gains 25% by adding a third card and has no performance issues..."

Also interesting:

http://www.tomshardware.com/reviews/3-way-sli-p55-nf200...