Windows 7 - will it be better to crossfire 2 6970s or go 1 7970?

generaly i know PCIe3 is supposed to be an all around bug fix to pcie 2 however, i already have a 6970 and dk how to afford a 7970 at this time, would 2 6970s (i already have 1, add another) costing me around 250-350, altimatly running post cross fire at 4 gb going to be more ore less powerful than a 7970. i know with the 7000s new frame work also that might make it a bit better to boot. anyways, help is appreciated

According to the reviews, a single 6990 (dual GPU card, requires Crossfire drivers) is generally much more powerful than a 7970. A pair of 6970s in Crossfire should outperform a single 6990.

Is your PSU up to two high-powered cards? You'd need two 6 pin PCI-E power connectors, plus two 8 pin. The manufacturers recommend a minimum of 550W for a single card. Adding a second card, that'd probably be at least 800W. 850+ would be better.

Downside to dual 6970s: Crossfire drivers, power & heat.

The DX11.1 and PCI-E 3 capabilities of the 7970 are of little consequence at the moment.

i would be fine in all other areas,i have more 8 pins and 6 pins for graphics cards. im looking at buying a new mobo which has 4 pcie 16 slots, 3 of which are pcie3, so if i ever upgrade i could, but i should be good with 2 6970s.
now i do have to ask, people say that cross fire has more problems than benefits, heat etc. shouldn't be a problem, size and space definitely wont be a problem. so what do people mean?

Personally ,I have just set up Two Gpu's for X-fire

I actually fixed my cards in a position heat wont be a problem

I use two different brand name cards but same make 6870

The Msi version comes with a almost 2 inch bridge which allowed me to go inbetween slots basicly i leaped over two slots spaces and have a 2 inch gap between Gpu's

Heat has not been a issue nor has the drivers so far I been playing many games and have expeirence Accelerated play beyond the normal

Only problem i can think of in crossfire is finding a good clock speed for the Gpu's to operate in Tandem

Other then that it has been pretty Excellent

Also if you are ordering a board with more slots it will defently help you with X-fire spacing and allow you to skip over for a better cooling solution

the board is designed for "crossXfire / SLI" and the seperation is prety large so i think i would need an elongated CrossXfire bridge

MSI I know for sure has a longer bridge

do you know where i could order a long XFire bridge? cuz im thinking im gunna order another Sapphire, i have always had good luck with sapphire so the more i can keep theirs the better, but im farily certain the bridge that comes with their cards are normal size

http://www.amazon.com/ATI-CrossFire-.../dp/B003NLGR7I

There you go

It will be the same size im useing it goes from the 1st to 3rd slot more then enough breathing room

ty for finding that for me and when i get all my upgrades in order i will make sure to try and get that