I have a GTX980SC but I want to upgrade it. I was trying to play Shadow of War and I cant even play it maxed out at 1920x1080. Which is frustrating because the game graphically doesn't look good enough imo to push my Overclocked System. But whatever.
 
If I want to upgrade, should I wait for the GTX1100 series at this point or is a GTX1080TI a good upgrade?
 
Does it make sense to go SLI anymore? If I can grab another 980 SC to hold me over for $150 that's better than spending over $1000 on a GTX 1080 SLI rig that might be outdated soon.  
 
I also plan on upgrading to a 144hz 2k monitor (maybe 3 of them)

really the 1080 ti is the only upgrade anyway

We could see Nvidia next GPU in the next 4-6 months.

demon09
Ya shadow of war is pretty intensive exspecailly with ultra textures. If you need an upgrade now the 1080ti is a good choice or a cheap 1080. If the games you play support SLI well another 980 may also be an option. I'd be tempted to try and hold out for the next gen in 4-6 months but I'd also be tempted to upgrade

I don't even know if 4 months is a realistic time. I would say we might be looking more of it being shown off in 4 months at an event like CES and released closer to E3 in the middle of next year.