GTX 970 SLI question?

[SuperSwordGaming]

So I'm trying to decide if I should upgrade my GPU, but after seeing the prices of a 1070/1080 I decided since I already have a 970, I could SLI 2 GTX 970's and be about the same as a 1070, if not do better. But I've never done SLI before, so I don't know much about it. I know that you can do any 970 with 4GB of memory and in theory it should work, but I don't know if I should go with a reference or custom 970 from another manufacturer. I have an EVGA custom PCB as of now, so should I get another custom, or a reference? And if I get reference, which should go on top? Also, do SLI bridges vary much, and if so could you suggest a good one? Thanks in advance guys!

My 970: https://www.newegg.com/Product/Product.aspx?Item=N82E16814487086

 

[DRagor]

I could SLI 2 GTX 970's and be about the same as a 1070, if not do better.

Unlikely. In most cases 2 970 will not even come close to 1070. You would be better selling your 970 and buying 1070.

 

[SuperSwordGaming]

I could SLI 2 GTX 970's and be about the same as a 1070, if not do better.

Unlikely. In most cases 2 970 will not even come close to 1070. You would be better selling your 970 and buying 1070.

So, are these results nonsense then? It took 2 minutes to find it.
https://www.youtube.com/watch?v=sb2nw6Sz4kY

 

[DRagor]

Just few examples, showing that 1070 beats 980 SLI, so 970 SLI stands no chance.

 

[ko888]

There are also games where GeForce GTX 970 SLI performs worse than a single GeForce GTX 970:

 

[SuperSwordGaming]

There are also games where GeForce GTX 970 SLI performs worse than a single GeForce GTX 970:

Well that's bizarre, but not every game is optimized for SLI I suppose. I appreciate the stats, but I've more or less decided to go with this, I just don't know about the layout or which card to get.