I want to run SLI but i dont know of my motherboard supports it

[Eternal cookie]

Recently a friend of mine bought himself a GTX 970.
Because his old graphics card is a GTX 660 2Gb he thought that maybe i can run them in sli since i also have a GTX 660 2GB. My 660 is MSI and his is EVGA but after some research i found out that that shouldn't be a problem. The thing i am not so certain about is if my motherboard can support SLI.
I have a Z77A-G43 (MS-7758)
i've done some research about this too but there doesn't seem to be a clear answer on this.

does anyone know if i can run SLI on this Board?

 

[DSzymborski]

Your board only supports x16/x4, which kinda makes it not very desirable. And at last check -- perhaps this has changed recently -- SLI requires at least x8/x8 (while CF will allow you to run a x16/x4).

 

[4745454b]

Agreed. Nvidia requires 8x/8x. To my knowledge there are not (current?) 16x/4x SLI boards. I'm not sure why you haven't found a clear answer on this. It should be pretty obvious.

 

[chenw]

SLI specifically requires at least x8 PCI-E lanes in all GPU's in the system, regardless of actual bandwidth of the lanes (EG you can have a motherboard that supports X8/X8 on PCI-E 2.0 lanes and SLI will work happily, but will refuse to work if you say you have a mobo that ends up with X8/x4 PCI-E 3.0, even though X4 3.0 and x8 2.0 have the same data bandwidth).

You will need to upgrade your motherboard to one that explicitly states it is SLI compatible to SLI. Xfire is much less stringent on the requirements, but I have heard of issues with Crossfire at x16/x4 configuration due to the massive bandwidth difference between the x4 and x16 (in addition that x4 is part of southbridge lanes which is controlled by the mobo, where x16 are northbridge, CPU controlled).

 

[Eternal cookie]

thanks for all the answers guys. Just one more question: Price/performance-wise would it be better to save for a 970 myself or should i buy a new motherboard for the 2 660s. i dont wanna OC so i dont need special features for that.

further my system has

i5-3570K
8Gb Ram

 

[DSzymborski]

thanks for all the answers guys. Just one more question: Price/performance-wise would it be better to save for a 970 myself or should i buy a new motherboard for the 2 660s. i dont wanna OC so i dont need special features for that.

further my system has

i5-3570K
8Gb Ram

If the 660 by itself isn't cutting it, it's better to save for a 970. You don't want to invest in a new motherboard that is now a couple generations old (don't feel bad, I have a Z77 myself). Single-GPU solutions are generally preferable.

 

[chenw]

I would also pick a single 970, but for a different reason: economy, convenience of upgrade and impending new chips.

It'll be more economical to just simply save up for 970 than it is to get an additional 660 and a new motherboard for SLI (you might even need a new PSU too), besides 660's VRAM is no longer enough for recent games and SLI does not alleviate VRAM bottlenecks. Plus, 660 has been EoL'ed for a while, so any 660 you buy now would be at least 2 years old, even unopened (700 series was launched in May 2013).

Also, with Skylake almost literally around the corner, you may also want to see what Skylake offers before buying a new motherboard.

Generally, I'd recommend that, if you want to go SLI, do it when you are doing a complete rebuild, and go SLI immediately. SLI is often a poor upgrade path, and gets worse as time goes by. I went SLI 970's instead of a single 980 because a single 980 was not enough for 1440p, and I went for it straight away.