I am close to 100% confident that in all of those games with the 680mx you will be able to hit 60 fps or higher with every setting up as high as it goes (Ultra quality), max Anisotropic filtering, and 4 or 8x AA. I am installing Skyrim atm to get a feel just running around and tracking the average framerate, but if my experience with everything else so far is any indication, performance is essentially 2x or in some cases 3x higher than the 2011 iMac performance. I've played all of those (great selection btw ;D) on my old iMac and performance was great on all of them.
Here are a few more Benchmarks using the built-in benchmarking tools for each game. These are all serious pixel-pushers that can bring GPU's but the most hearty to a standstill. I'm very very impressed with the Crysis 2 scores, and WOW now I finally have a machine that can play GTA IV
. In my opinion, anything over 30fps is just pure gravy, and something that can play on max settings while hardly ever dropping below 30 is amazing. Sure these scores were available with Mac Pro hardware, but for an all-in-one, you can't beat this performance.
For everyone asking about heat and fan noise, I have literally been benching this non-stop for the past 5 hours and the only time the fan kicked on was while playing Crysis 2, and even then it really wasn't that loud. Some fans can just have the most obnoxious whine, this one isn't as high pitched as some macs I've owned in the past. After an hour of Just Cause 2, the back is slightly warm to the touch, but nothing as hot as last gens iMac.
As reported by GPU-Z:
Ambient GPU temp - 39 Celsius
After 25 minutes of cycling the three Crysis 2 benchmarks GPU temp - 68 Celsius
Just Cause 2
(2560x1440, Maximum possible quality, 16x AF, High SSAO)
Dark Tower - 2xAA - 36.59 Avg fps
Dark Tower - 4xAA - 36.55 Avg fps
Desert Sunrise - 2xAA - 45.15 Avg fps
Desert Sunrise - 4xAA - 43.73 Avg fps
Concrete Jungle - 2xAA - 32.63 Avg fps
Concrete Jungle - 4xAA - 33.00 Avg fps
Metro 2033
(2560x1440, DX11, Maximum possible quality [Very High preset], 16x AF, Analytical Anti-aliasing)
Run 1 - Very High preset, PhysX Disabled, DoF Disabled - 30.59 Avg fps
Run 2 - Very High preset, PhysX Enabled, DoF Disabled - 27.93 Avg fps
Run 3 - Very High preset, PhysX Disabled, DoF Enabled - 18.19 Avg fps
Run 4 - Very High preset, PhysX Enabled, DoF Enabled - 17.23 Avg fps
Run 5 - High preset, PhysX Disabled, DoF Disabled - 45.86 Avg fps
Run 6 - High preset, PhysX Enabled, DoF Disabled - 41.80 Avg fps
Run 7 - High preset, PhysX Disabled, DoF Enabled - 23.97 Avg fps
Run 8 - High preset, PhysX Enabled, DoF Enabled - 22.39 Avg fps
Crysis 2 - Maximum Edition
(2560x1440, DX11, Maximum possible quality [Ultra preset], Edge AA, Hi-res Textures On)
Times Square - 2xAA - 31.5 Avg fps
Times Square - 4xAA - 31.4 Avg fps
Downtown - 2xAA - 31.1 Avg fps
Downtown - 4xAA - 31.0 Avg fps
Central Park - 2xAA - 30.1 Avg fps
Central Park - 4xAA - 30.0 Avg fps
Grand Theft Auto IV
(2560x1440, Maximum possible quality, All Distances at 100, 16x AF)
Benchmark Test w/ no AA - 63.63 Avg fps
Benchmark Test w/ Control Panel Forced 2x FXAA - 60.71 Avg fps
Benchmark Test w/ Control Panel Forced 4x FXAA - 60.31 Avg fps