You know that's right. You can at least keep the GI maps. You "squeaked» UPS, then you just take it and keeps himself in rendering the form in which it is you have. After power-on has appeared, loads a previously saved GI maps from the disk and re-render the final render, but in the opposite direction. That is, go to the Settings tab, scroll Unfold «V-Ray :: System» and tick «Reverse sequence» in it. Then the buckets will run to the other side and will render the other half (a part of) the rendering, to which you have not yet reached the first set. When you see that the buckets had already gone to consider that part of the picture that you have already been calculated before, rendering stops. Keep pictures, throws it and the previous one, with the first half render in Photoshop, and then do one of two full-fledged. All.
Why not in one renderer is still no adequate mechanism for storing intermediate results render incomprehensible 🙄 But there it is.
As for the question about the power of UPS is not necessary to do a dump and hang several different questions in one subject. For questions about the computer. technique, we have a special section 3d iron . And it is not closed, only some of the topics covered in it, do not confuse😉