Consider running LHC "atlas" It can consume up to 8 GPUs. It requires VBox which can be downloaded from Oracle. Version 6.x works fine, no need to reinstall "boinc+vbox". Image files run about 1gb so downloads can take a while on slow systems. Be sure to read this post first
https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=5348&postid=41896#41896
The memory requirement of 3gb ram + 0.9gb for each CPU includes virtual ram so a 12gb system can easily handle an 8cpu job.

Warning; my app, the "7.15.0" one that fixes the 10 minute delay does not work when CPU Milkyway tasks are being crunched in addition to GPU ones. One should split up GPU and CPU tasks to different projects anyway.