intel graphics - Dota 2 lagging in Steam when running on MacBook Pro

I installed Ubuntu on my Macbook Pro recently. But DOTA 2 is very much laggy in Ubuntu 16.04. It runs crispy in OSX. I tried updating machine and all, but no use.

The graphics card shows Intel Haswell Mobile in Ubuntu and Intel Iris Pro 1536 MB in OSX. Is it a graphics related problem? How can this be fixed.

Note: I have seen Dota 2 running fine on Ubuntu with laptops of very ordinary specs.

Some more information as per comments:

1. The output of lspci | grep VGA is

   
   

   00:02.0 VGA compatible controller: Intel Corporation Crystal Well Integrated Graphics Controller (rev 08)




2. It plays 60 fps 4k videos perfectly fine.