Would a gtx titan be better than two 7950s or two 660ti ? I mainly play crysis 3...but the recent articles about frame time or something like that confuse me from buying these setups and even 670s and 7970s are in the list..!
http://www.hardocp.com/article/2013/04/22/nvidia_geforce_gtx_titan_3way_sli_review/10#.UXW0dhPn-Uk
We've been talking about these issues for as long as we've evaluated multi-GPU performance in games. It doesn't take special software, or benchmarking, or frametime analysis or frame by frame rendering to experience and discover these issues. All it takes is actually sitting down and playing games to see and feel the differences between NVIDIA SLI and AMD CrossFire. Since we began our real-world evaluation method in 2003 that simply entails us playing games with these video cards just like gamers do, we've been able to see and feel a difference between SLI and CrossFire that we've talked about in every SLI and CrossFire evaluation.
As you look at every game in this evaluation, you will notice one thing common in all the graphs, the red line of performance is vacillating, sometimes tremendously. This red line depicts the Radeon HD 7970 GHz Edition 3-way CrossFire performance. It is commonly inconsistent in framerate, has large peaks and valleys, dips and drops, and ups and downs as you play each game. It is erratic, and when you compare it to the two NVIDIA SLI configurations you notice these are smoother, more consistent, and less unruly. We've noticed this for years, we've seen it, we've talked about it, and it is very evident the more GPUs you add. It seems 3-way CrossFire really shows it the worse.
Game players notice this change in FPS, they feel it as they play, and to compensate for it you have to aim for higher framerates out of CrossFire to bring the smoothness back. It is a reality right now, and one needs to keep this in mind when shopping for multi-GPU gaming solutions. While there do exist some granular testing to perhaps explain it, all one has to do is sit down in front of both setups and you will be able to tell which is smoother.
We are looking at some ways to better document this in an objective manner with that aforementioned software. If we can somehow show you this, other than just words, we will. We will be looking at this further in the future, but rest assured you do not need a frame time graph to tell when gameplay is not what it should be and that of course is what we all use these video cards for.