Yea, we gotta look at a lot of benchmarks and compare.
Yes, the 2600k, even the 2500k will be faster overall due to their greater OC room, and will reduce any bottlenecks if any, there isn't much 2 580's can not handle, as most games will be GPU bound, and the CPU is a less determining factor in your case.
If anything you should OC your 950 to 4.0 or 4.2 with HT OFF. You'll see better temps, then you would with HT On, and performance will be about equal vs HT ON.
I think that once you add a 3rd card, that's where bottlenecking of the CPU will become more noticeable.http://www.guru3d.com/article/geforce-gtx-580-3-way-sli-review/17
We're going to need more clock for clock data at 4.0 for example, plus say 4.5 2600k vs 950 @ 4.2 to determine if the 2600k is a worthwhile upgrade from the 950. Right now, I don't feel it is.As Tom's put it.
The moral of the story here seems to be that, as you step up to higher-end graphics, a dual-core processor simply isn’t fast enough.
Also interesting is that the six-core Phenom II X6 1100T, though not the fastest offering, opens up enough headroom to enable the highest minimum frame rate in our Metro 2033 benchmark. That advantage shrinks as you crank resolution up, though, shifting more demand onto the GPU. By the time you hit 2560x1600, eight of 10 platforms fall within one frame per second of each other.Edited by 2010rig - 1/3/11 at 9:12am