Can an LTSP server use a GPU for client rendering?

Question

I am setting up an LTSP (Linux Terminal Server Project) server and some Raspberry Pi's as thin clients. Could the server make use of a GPU to increase the performance of rendering the thin clients' screens?

Answer 1

Not at all, unless you manage to hook into the host's expansion bus somehow, but then you would need something else instead of LTSP.

Your uplink transfer speed will probably count for the most, and I think on the Raspberry the 100 Mbps Ethernet is going to be your best option.

There are ways to help rendereing speed, which is mostly dependent on things like number of colors, or color depth, resolution, compression (if used), and even selecting update priorities assigned to selected rectangles of a display - but all these are software driven, and has nothing to do with the actual GPU hardware. Nevertheless, with the right software on optimized setting the difference could be quite significant.

When your uplink is ready look into the available VNC clients, or client/server pairs, a few supports all of the features above, and maybe more I do not know about.

Good luck, I would like to try Raspberry myself, I just do not have the time for yet another project :)

Answer 2

Actually server uses GPU in thin client environments. We are running Ubuntu 15.05 Vivid in office with about 25 terminals over Gigabit 3 channel 802.3ad links. While using Nouveau (opensource) driver, we experience poor graphic performance on clients, graphic glitches with Gnome while Plasma refused to run due to non GPL 2.0 compatible hardware. After upgrading to Nvidia preparatory driver, Plasma runs fine, no bugs, smooth graphic effects. Therefore, GPU on the server will directly affect rendering on clients. Pick a good graphic for your LTSP environment.