Are we sure that mining over integrated graphics isn't profitable last days, especially with free electricity?
If mining monero through CPU is okay, then why mining whatever through integrated graphics is bad idea?
Because, as I ALREADY EXPLAINED, the iGPU has pathetic performance even compared to a VERY LOW END discrete card per the TESTING I did on both my Intel AND my old AMD iGPUs.
Iris Pro is NOT going to be anywhere close to the performance of the Nvidia GTX 750 ti, much less the MID RANGE 9xx cards.
The top end Iris Pro iGPU *MIGHT* manage to match my AMD A10-5700 as it has about double the cores of the Intel I did testing on, but that's STILL a sad joke compared to any discrete GPU less than 5 years old.
Keep in mind that Monero is specifically designed to make both CPUs and GPUs fairly close to equal on performance - nothing else has managed to keep them in the same ballpark to date, and even Monero is failing on that lately to some degree with the Vega (back when they could be found near MSRP).
The only mining benchmark I have for my Iris Pro 580 is with mining bitcoins. I can pull off slightly more than 100 MH/s for bitcoin though drops to 90 sometimes, overall which is roughly equivalent to a GT 740 that I also tested with. By comparison, an old BlockErupter USB ASIC I have for mining bitcoins only pulls off 333 MH/s. So while the Iris Pro might not be as good as a GTX 750 Ti, it's able to consistently keep up with the GT 740 without needed to be overclocked or anything. In fact, I think it even manages to keep up with the GT 940M in my Surface Book.
So for cryptonote currencies like Monero being very CPU friendly as it is, mining with a high end iGPU isn't such a bad idea. And now that there are Intel and Ryzen CPU's coming with Vega iGPU's that'll make mining with an iGPU even better. But as far as Intel GPU's, based on my experience with mining bitcoins, the Iris Pro 580 isn't that bad compared to some low-mid range NVidia 700 series GPU's.