The video card has nothing to do with render times; so long as it properly supports OpenGL and has sufficient memory to handle display ports, there should be no problem. Nvidia -is- a little more stable (more due to driver than hardware work), but about the only thing you =might= need to do is disable the background drawing thread, if you are having issues with what Vue does with the work panels. If they aren't glitching, you have no problems there.

 

The long render times will be found in your settings. Spectral atmospheres add time. AO adds time. A couple of reflective surfaces facing each other while raytracing can bring any renderer to its knees. The overall size of the image can be a real killer, if your system lacks the physical resources to actually do it, and has to render a bucket, move it to the swapfile, do another, wash rinse repeat.... Hard drive access times are the biggest remaining bottleneck, as they are in milliseconds, and you memory is moving in fractions of microseconds (and some of the highest end stuff in nanoseconds). About the only thing you can do is to go into your render settings, turn off all the time eating features (do a preview render), check that time, then turn the fun features on one at a time and see what happens. Likely it is a combination of 2 or more advanced features that is causing the effect.

If it is a preview render that is taking 24 hours, there is something wrong with the scene setup. Or you've overclocked your system for gaming, and either the OS or Vue does not like your settings.