I keep getting this error when tuning my GPUs

I'm using NBminer and tuning with MSI afterburner.

When I push my clock past a pretty low threshold the miner keeps crashing and giving me 'CUDA error: an illegal memory access was encountered'

Is this related to the system RAM in any way? I've currently got a pretty slow 2x4gb (8gb) set at the moment, would upgrading to a faster 16gb set allow me to get a better clock without crashing?

Thanks for the help!