I seperate my workflow in phases : loading and sorting, detection, editing, rendering. All groups in a projects are doing one phase together before I start the next phase.
It is only during the editing phase that I am using my GPU and it's memory. This memory is now 4 GB, but soon 8 and maybe even more due to the addition of extra GPU cards.

It would be very efficient if this GPU memory is used (as an extension of normal memory) while no editor is open.