Oh, I've just got an idea, kinda stupid that I haven't thought of it before, because I use it myself all the time: Go to the render-settings and set the number of shadow-ray's on a low value, like 1 or 2 in the render-setup, it really speeds up rendering glass and metal, and it might make your machine more stable during rendering because of that. I'm defenitely interested in your progress.

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