GTX 750ti Bottleneck i7 CPU

Solution
Just the hyper threading on the i7's will artificially show lower cpu usage on any game that can not use all the threads as well.

If you play MMO's just note that those will jump from CPU to GPU demanding as well. My 2600K @ 4.4 is not enough for large scale guild wars 2 battles. It is playable, but has NO CHANCE to hold 60fps in these large scale events.

I played Bioshock Infinite with the default settings without any issues on a 650 ti(with the same cpu above when my 670 was in RMA), you should at least get med settings on a good number of games and high on less demanding games.

Please note that frame rates will vary to an extent on almost any system.

You can get an idea of average performance under different games here. Please...
Depends on your resolution and the games you are playing... For the most part your CPU will be held back by your GPU - meaning your GPU will run at 100% all the time while gaming (if you have vsync off) while your CPU might be around 20-40% load.
 
Just the hyper threading on the i7's will artificially show lower cpu usage on any game that can not use all the threads as well.

If you play MMO's just note that those will jump from CPU to GPU demanding as well. My 2600K @ 4.4 is not enough for large scale guild wars 2 battles. It is playable, but has NO CHANCE to hold 60fps in these large scale events.

I played Bioshock Infinite with the default settings without any issues on a 650 ti(with the same cpu above when my 670 was in RMA), you should at least get med settings on a good number of games and high on less demanding games.

Please note that frame rates will vary to an extent on almost any system.

You can get an idea of average performance under different games here. Please note the settings are higher than recommended for optimal performance on more demanding games.
http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_750_Ti/7.html
 
Solution
You should be fine as long as you do not mind playing with settings in some games to optimize performance. This is normal for all mid level cards.

I was actually impressed with the 650 ti's performance for its power consumption(and quiet operation compared to the last generations mid level cards) and the 750ti is a bit faster and uses even less power.