I too have this problem
Core i5-4460 / hd4600 graphics
8GM RAM 1600 MHz
Yes even watching youtube videos it is QUITE apparent that there are missing frames and the stuttering is most obvious when watching
side to side motion...it looks TERRIBLE!
I just bought an OEM Dell 3847 to replace my ancient HP Pavilion 7955 with an old nVida TNT riva 64 graphic card!
My old system has NO issues with stuttering at ALL and it is 13 years old!
OK, Intel where is the engineering team on this the problem, it has been around for a LONG time now and needs to be addressed.