Good half lenght video card to work with Linuxcnc

A different video system may help, but latency issues ( millisecond sized latency spikes )
with laptops tend to be power management related and are often not fixable.

I've taken care of the smi issues and others. This is my last step, I feel. Again, the open source drivers for the nvidia chipset have some minor issues that are holding me up. So if I get a an open source video card, it should fix the issue? I'm not familiar with video cards. Does anyone use a video card that is working well for them?