I'm trying to find out if it's possible to have BOINC have different rules for each GPU on my system. I'm getting a new GPU, but am leaving in my old GPU to keep crunching. I'd like to have my current GPU running BOINC tasks 24/7, but have exclusive apps or not running while my computer is in use for my new GPU. Is there any way to do that? My system runs Windows 8, and I'd use any BOINC version that makes this possible.

This is an acknowledged weakness in the original coprocessor design for BOINC (https://boinc.berkeley.edu/trac/attachment/wiki/WorkShop14/workshop_14.pdf, slide 52), which is going to be changed. Sometime, we don't know when.

Until then, there's not much you can do, except set up two (or more) sets of configuration files, and write a script to switch between them.