I want to know if how much of a performance boost will I get if I upgrade my motherboard from x16/x4 PCIe 2.0 to x8/x8 PCIe 2.0
I'm running a 5770 crossfire setup. Would there be a significant improvement in terms of frame rates, 3d rendering, etc?
how great is "great" really? is it worth the money spent on another brand new motherboard? I have a regular asus P7P55D x16/x4 motherboard, say if I upgrade to a msi 890gxm-g65 which has x8/x8, would it be worth the money considering I only have the 5770 which is a mid-range card?
Well you are right about 8x, but as for 16x4x,the loss is more than 10-15%,sometimes it even gets a performance hit of 50% (depending on the game and settings)
Definitely its worth it if you look at the link i posted,it says that
"The easy solution for P965 and P35 Express systems is to simply use a single, more powerful card. At the very least, the issue we encountered where a secondary PCI Express x4 slot’s limited bandwidth hurt performance can be avoided by using a single card, so comments such as "CrossFire doesn’t work right" wouldn’t apply to single-card CrossFire solutions such as the HD 4870 X2. But the point of this article was to judge the viability of adding a second card when a reasonably good card is already installed, and this is an area where P965 and P35 Express motherboards simply cannot be upgraded to compete with modern builds."(In which P35 supports CrossFire at 16x4x which is pretty much like your board and P45 chipsets support CrosFire at dual 8x(same as P55).
but you are switching from Intel to AMD which you have to change your CPU too, so IMO buy a P55 motherboard(with dual 8x CF support) and you can save some bucks.
Now is that Crossfire only? Could explain why what I found had such contradicting ideas.
Yes that's for CrossFire,but its the same results for single mode too, however i haven't seen any motherboards which have only one PCI-E 4x slot, most of them have PCI-E 16x or 1 16x and one 4x slot, so mostly the comparison is between 16x4x and dual 8x/16x