using mining rig for gaming and simulation?

[volish]

Hi,

At the moment I do simulations on programs like Ansys and was looking to upgrade to a new PC to better cope. Ideally I would also like to use it for a bit of occasional gaming (quite like the game quake champions) . I am interested in building one of those open case gpu miners and wondered if I added a good CPU, SSD and high RAM I could use it for all three purposes (not necessarily at the same time) ? How limiting are those GPU risers?  Am I correct in thinking that is the main bottleneck?  If so, are there alternatives that would limit this restriction?

Thanks very much for your time and help.  Apologies, I have posted this in the wrong section, please feel free to move it appropriately.