Is there a problem with GeForce 750M performance on gaming? I play games on my Mid-2014 retina MBP, which has both Iris Pro and GeForce 750M 2GB. One of the games that I play (League of Legends, which has a 'beta' OS X client, but I highly doubt that this is the reason) sometimes runs slow on graphics-intensive scenes. Today, I forgot my GPU on 'Integrated only' (I use gfxCardStatus) and entered the game. Interestingly, the game almost never slowed down at all, even on graphics intensive scenes, running smoothly on 60FPS. I've upped the settings and it was still running smoothly at settings which severely affected GT750M's performance. I've doubled checked the active GPU and yes it is Intel Iris Pro. How can this happen? How can integrated graphics perform better than a GT750M on gaming? I know Iris Pro is a great 'integrated' card (compared to other integrated cards), but I highly doubt that it does better than 750M. If it really did, then why would it co-exist with 750M anyway?

Why would this be happening?
Intel is making big improvements in the Integrated Graphics performances.

They are actually taking a portion of the Nvida market in doing that.

To Intel, the Nvidia is just a parasite, so if they can do better with the iGPU performance, ppl wont need it.

Intel will be introducing next gen CPU with some powerful iGPU in 2015.

There is no official benchmarking for the Iris Pro vs G750 but as usual the performance is highly game type dependent.

As you have discovered for the League of Legends it looks like the Iris is actually doing better then G750.

There are some games where the G750 is doing better, like Startcraf2 and Heaven.

see this report for more.