Hi, no single (Lowend) GTX 760 but I fixed all issues with performance copying preset settings to Linux. Not all settings are reachable on Linux atm. but I am not in hurry.
I know you are a speed fan but may you remember a patch to add some wait states to the GPU to don´t block your system completely during render?
I cant find it yet at developer.blender.org.
I can render in Octane and surf the internet with some limitations without slow down render time. May a few % less.
It would be nice to have a switch for it, may GPU load High/Low or something.
Thank you for the support and for E-Cycles, mib