2015 Viewport playback issues

[Tim Bolland]

Hi, I am making the jump from 2013.5 to 2015 and I noticed that there seems to 
be a playback issue. Working with a pretty simple scene the frame rates aren't 
great, and there is a noticeable stutter even when the frame rate is clamped. 
Just doing a test, a comparison between 2015 and 2014 is 40fps vs 250fps. I 
realise this could be a hardware issue but we have updated our drivers and 
haven't any issues before. Any ideas?
Regards,
Tim