PCI-E 2.1 Bandwidth, is 4x really bad? [Crossfire]

[Internet Swag]

My mobo supports Crossfire, but the second lane will run at 4x, is this a big problem? 

[samcool55]

You should be fine, i am running 6970's in crossfire, 1 at 16X and the other one at 4X, haven't experienced any problems with it, the gpu's can be both pushed to their limit.

If you use dual-gpu cards, can it cost you a bit of performance, but you should be fine.

[dragoon20005]

fine is a very loose word for CrossFire configs especially with 4x PCI-E ver 2.0

 

many complain that even with dual 280X

 

users getting like a small increase on fps with the same resolution before they when dual GPU

 

 

note this is on stable games like Crysis and Metro Last night

 

it is better to look for slightly better mobo which supports at least 8x PCI-E 3.0 for dual gpu configs

[SkilledRebuilds]

SNip

NVRMInd.

[ForsakenLive]

Check this benchmarks, they use different PCIe bandwidths.

http://www.techpowerup.com/reviews/Intel/Ivy_Bridge_PCI-Express_Scaling/15.html

[fringie]

Well it depends on how bandwidth hungry the card you want to CF is. You currently have a 7850 (according to your sig) so I'd imagine you want to CF a 270 or 7850? If so you'll be fine, you might loose a few FPS but that's about it.

[dragoon20005]

on mid range cards you may or may not feel the difference

 

the performance will really suffer when you try to X-Fire with higher tiers cards like the HD7950/280, HD7970/280X and above cards

 

do remember to verify your boards maximum PCI-E lanes before you try doing any multi GPU configs