If I was to setup a mining machine with quad 750 Ti's powered by a sempron 145, would 4gb of ram be enough to run ccminer efficiently, or would 8gb be needed?

I tried to run 4x 750 Ti's with my sempron 145 and 2gb of ram a few months ago and that didn't end well. If anyone is currently running their miners with a low powered CPU such as a Sempron 145 I'd appreciate if you chimed in.