Not doubting your post, but I am just curious. What games bottleneck your CPU with a 5750?
I suppose it is possible if you turn down the IQ settings to shoot for 60fps.
I have a 7770 and an i5 2320 and have only been able to max out the CPU by playing a 10 player skirmish match in SC 2. I am satisfied with 30 to 40 fps though, so I may be using relatively high video settings compared to you.
any i3 is much slower than the i5 2320.
it's impossible to list the games, because there are to many, and I haven't used that card for quite some time,
but even on things like Witcher 2 (famous GPU bound game), GPU load on the 5750 could go down to 50-60% at my regular settings during the worst fight (and framerate was 24FPS with some stutter, when in most parts of the game the frameate is around 40 with the GPU fully loaded at the settings I used), other games like GTA 4 it would easily go to 60% GPU usage with the framerate at 30-25 in some bad areas.
Skyrim also had a few places where the CPU couldn't handle the keep the VGA at 100% (with medium to high settings and low anti aliasing I think)
same goes for any MMO I've played, like LOTRO or SWTOR, with sub 30FPS and low GPU usage in the worst places (when in the 100% GPU load areas was over 50)...
and things like like Sleeping Dogs (probably medium), TF2 and others.
obviously I'm talking about a lower level of graphics settings, like medium and not 1080p which for me was the most comfortable way of playing these games (with a smaller screen), but it's all relative,
a slower card doesn't necessarily mean lower frame rate and less CPU load, it can simply mean lower visual quality (which can or cannot affect the CPU)