I'd like to start a thread where we can do some experimental comparisons between the performance of Iris Pro and the 750m, because from what I've seen already this is going to be a very complex topic. I'll start with a few interesting data points I've collected so far: I started with Unigine Heaven 4.0, a pretty common (and small) benchmark. I tried two different modes and was surprised by the outcome: -1440x900 Medium: --Iris Pro: 709 --750m: 717 -1440x900 Low: --Iris Pro 1205 --750m 1237 So here we're looking at performance deltas in the range of the normal variance between individual tests with the same GPU. In fact they're so close I'm now uncertain whether or not gfxCardStatus is actually forcing the 750m off or not (it indicates that Iris Pro is active in both gfxCardStatus and the Activity Monitor, however it's hard to be certain). Next I ran Minecraft. In order to properly test MC you'll need a utility to control screen resolution directly (Minecraft tries to render pixel doubled on Iris Pro in HiDPI mode, which completely throws off the results). I used this simple one here: http://www.reddit.com/r/apple/comments/vi9yf/set_your_retina_macbook_pros_resolution_to/ I'm sure there are more robust options but this works and is very simple (I've also been using it for quite a while on my 17" just to have quick switching between 1920x1200 and 980x600 HiDPI). This is at full 2880x1800 resolution (which you'll need to set at the desktop with a utility as mentioned above): -Iris Pro: Average frame rates in the 80-90 range. -750m: Average frame rates much lower, 50-60. Not sure what to make of this. Drivers? I'd love to see some numbers from other users to verify that it isn't simply an issue with my machine, but at the moment I have a fairly simple theory: Intel's OS X drivers could be significantly better than NVidia's. It's also very likely that there's nearly zero performance delta between the OC'd 650m seen last year and this year's 750m (same chip). Anyway, I'd love to see results from other users, and I'll be posting more when I've tried other benchmarks (hopefully including some actual games). I don't intend to actually game on this machine, however after all the debate between iGPU and dGPU these results are very interesting.