I have a gtx 690 and an i5-3570k (4.1ghz) with 8gig of corsair ram (1866).
I have a 1440p display (60) and i hate the fact that i cant play my games at smooth 60 fps (ultra)
I have a bitefenix itx case so i only have room for 1 GPU. What should i buy? My price range is 400-600 EUR.
I will be looking into upgrading in the future after this. (2x gpu, bigger motherboard etc.)
Assuming that the games you play are able to take full advantage of SLI and you have correctly optimised your graphics settings I beleive your options are limited. An upgrade to a single card won't bring a massive uplift in FPS for most titles.
Your options though are;
R9 Fury X
If you purchase lesser cards then you'd probably want to start off with Xfire or SLI straight away and that won't give an upgrade path, but two R9 390's would give you a performance boost for games that support XFire.
I believe a single GTX 980Ti or R9 Fury X would be within your price range. You'd likely be better off sticking with Nvidia as that is definately the faster card for most titles.
Is there any chance you could pick up a second 690 cheap?
EDIT: I've only just noticed you have an ITX case. You are really limited. Either wait a year or go with the fastest GTX 980Ti you can find. EVGA and MSI do hybrid water cooled ones that should fit your case.
The Fury (non X) is a great 1440p card.
Oh ok I was thinking the same thing :/ 690 are cheap yes but isnt there a problem with dual 690 ? Is quad sli (not really but alike) going to work well ? So if i go with the 980ti... am i going to have chance to buy another one when i upgrade? Will the CPU handle it?
The CPU is fine up to a 980 Ti @ 3440x1440 as that's what I'm typing on right now as my 5820K X99 board just went back on RMA. I went from a GTX 670 to a 970 then 2 x 970 and finally a 980 Ti with my trusty i5 3570K. In most games the i5 3570K was not a bottleneck.
Probably the biggest benefit I've noticed outside of obvious productive multi-threaded software where the 5820K has a noticeable benefit was playing Fallout 4 in the Boston city areas where the extra cores (both CPUs running at a similar 4.2 GHz) allowed the X99 system to maintain close to my 75 fps cap where the i5 3570K setup dips down to 50 fps every now and then.
To be fair I'm also running a Hyper-V VM in the background on the i5 at the mo and won't be able to test that on the i7 until I get the the mobo back.
I tend towards a single GPU now after running SLI for a year or so just to reduce hassle, heat, power etc. but yeah beyond a 970 SLI setup I reckon the i5 is probably going to start to struggle.
I will be looking into a 980 ti then :D guys thx 4 advice!