i haven't found much but what I did find didn't tell me anything.I'm going to find graphics performance benchmark interesting seeing that the new Skylake processors with Iris includes 64 MB of eDRAM. That should help tighten the performance gap with dedicated solutions. Kudo's to Microsoft for going this route.
Here's an expectation from notebookcheck related to the i5-6300u
The integrated graphics unit called HD Graphics 520 represents the "GT2" version of the Skylake GPU (Intel Gen. 9). The 24 Execution Units, also called EUs, are clocked at 300 - 1000 MHz and offer a performance somewhere in range of a dedicated GeForce 820M. Games of 2015 can thus be played smoothly in low settings. For more information about performance and features, check our page for the HD Graphics 520.
the i7-6650u
The integrated graphics unit called Iris Graphics 540 represents the "GT3e" version of the Skylake GPU (Intel Gen. 9). The 48 Execution Units, also called EUs, are clocked at 300 - 1050 MHz and offer (thanks to the fast eDRAM cache) a performance sligthly above a dedicated GeForce 920M. Games of 2015 can thus be played smoothly in low or medium settings. For more information about performance and features, check our page for the Iris Graphics 540.
The core m3-6y30
The integrated graphics unit called HD Graphics 515 represents the "GT2" version of the Skylake GPU (Intel Gen. 9). The 24 Execution Units, also called EUs, are clocked at 300 - 850 MHz (limited by available TDP headroom) and offer a performance somewhere in range of the old HD Graphics 4400 (Haswell, 15 W). Only a few games of 2015 can be played smoothly in lowest settings. For more information about performance and features, check our page for the HD Graphics 515.
Anxiously waiting the first usable benchmarks on these SoCs.