SRS V3 Logitech SmartDock and HDMI Video, Audio issues when hosting screen sharing from dock to TV

We have similar setup and had similar issue, that has been addressed since. Posting for benefit of others, who will hopefully not waste as much time as our team.

Our setup : Surface running W10 1803, and SRS 4.0.64.0. Logitech Dock with extender, Polycom CX5100 and DUAL Samsung 4k TVs (6100 series).

Our issue: Every time we had local sharing enabled from the room and 4+ participants, conference crushed and Surface became unresponsive. We observed high GPU usage(90%) during those events. It was not happening on previous versions of SRS.

During investigation we found out that even when you change desktop resolution to Full HD(1080p) the Surface will still drive TVs at 4k resolution. The up-scaling to 4k will happen in Surface GPU.

We needed to change "active signal resolution" to 1080p( to match desired desktop size). 

When still running at 4k active signal resolution we disabled "transparency effects" (in colors section), and locked scaling for TVs to 100%, it reduced GPU usage by 50% when still in 4k.

We didn't manage to reproduce that issue after 3 changes above. GPU usage is below 20% with local sharing in 6-way conference and dual TVs running at 1080p.

Hope it helps