Is 2-way SLi GTX 1080 worth it for UltraWide (3440x1440) build?

[boole]

Hi I am planning an ultrawide build with the 21:9 Acer Predator X34A 34" 3440x1440 100hz g-sync monitor.

I am finding it hard to figure out how much FPS improvement SLi 1080's would be over just one 1080.

All the benchmarks I can find comparing one 1080 to SLi 1080's seem to focus on 2560x1440 and 4K.
CPU will be: i7-6850K

Also, a video I watched said the 1080 SLi performance should improve over time with drivers and game development.

Could anyone give me advice here?

I'd be happy to sell 1080('s) and upgrade to 1080ti in ~Q4 when they come out, but don't want to drop £650 more now for second 1080 if it's not really going to be worth it.

 

[_JakeDavies]

Hi, SLI would give you a performance gain but it's mostly down to the games dev's. If the game doesn't support SLI then your stuck with using just a single card, if the SLI support is good then you'll get about 40-50% performance of the second which isn't great but would definitely give you a 20-30fps gain depending on the game. If the games you are playing have good SLI support then you can see about an 80% performance gain and the fps will increase dramatically. Have you got the monitor already? If not I would stick to your current resolution and wait until the 1080ti. This will ensure that you can get lot's of fps from a single card so that even if the SLI scaling is bad in a game then you can still get good performance. 1 1080 will get around 50-60fps on modern games, maxed out at that resolution so I'd expect around 60-70 fps for the 1080ti which would be certainly playable. Once you SLI the 1080ti, you should have 100Hz locked in most games.