[yla92]

I am also on 9550 with Ubuntu 16.04. I upgraded RAM to 32GB. I mostly do Android development (gradle and Android Studio eat a huge amount of memory). I've run into a few weird issues with different version of Linux kernel. Some kernel version caused no sound at all. This is such a common topics among Ubuntu users and there are so many solutions about that. I've tried most of them (solutions around alsamixer and pulseaudio) only using certain version of kernel works for me.

I am curious which linux kernel version people (and your co-worker) are using though.