glxgears is an OpenGL program that reports FPS (frames per second) numbers. I find this program useful to test out OpeGL Renderer such as simple comparison between VNC, VirtualGL and of course the Direct-From-The-Machine itself.
For TurboVNC (unencrypted) churned out about on a Local LAN
# glxgears
6028 frames in 5.1 seconds = 1186.369 FPS
6000 frames in 5.1 seconds = 1178.267 FPS
5760 frames in 5.1 seconds = 1132.999 FPS
5760 frames in 5.1 seconds = 1133.431 FPS
5520 frames in 5.0 seconds = 1096.104 FPS
5147 frames in 5.0 seconds = 1027.200 FPS
5160 frames in 5.1 seconds = 1016.540 FPS
5160 frames in 5.1 seconds = 1016.316 FPS
5160 frames in 5.1 seconds = 1016.578 FPS
5160 frames in 5.1 seconds = 1016.974 FPS
5160 frames in 5.1 seconds = 1018.695 FPS
For SSH and Xming churned out about on a Local LAN. But the glxgears image refresh is definitely slower than TurboVNC even though the FPS is similar.
# glxgears
6761 frames in 5.0 seconds = 1345.283 FPS
7022 frames in 5.2 seconds = 1343.998 FPS
7021 frames in 5.2 seconds = 1337.664 FPS
6632 frames in 5.1 seconds = 1288.340 FPS
6632 frames in 5.1 seconds = 1297.666 FPS
6760 frames in 5.2 seconds = 1309.137 FPS
6632 frames in 5.2 seconds = 1266.929 FPS
7022 frames in 5.3 seconds = 1330.755 FPS
6631 frames in 5.1 seconds = 1309.255 FPS
6632 frames in 5.0 seconds = 1314.089 FPS
6891 frames in 5.3 seconds = 1305.207 FPS
6631 frames in 5.1 seconds = 1291.670 FPS
For Direct-From-The-Machine. This is the best performance
# glxgears
61237 frames in 5.0 seconds = 12247.371 FPS
65314 frames in 5.0 seconds = 13062.798 FPS
60291 frames in 5.0 seconds = 12058.135 FPS
64627 frames in 5.0 seconds = 12925.391 FPS
64976 frames in 5.0 seconds = 12995.109 FPS
64949 frames in 5.0 seconds = 12989.766 FPS
64961 frames in 5.0 seconds = 12992.117 FPS
64953 frames in 5.0 seconds = 12990.459 FPS
64920 frames in 5.0 seconds = 12983.886 FPS
For VirtualGL on VGL Image Transport with a Direct X11 Connection. Performance is very good near Direct-From-The-Machine
6559 frames in 5.0 seconds = 1311.784 FPS
6573 frames in 5.0 seconds = 1314.600 FPS
6548 frames in 5.0 seconds = 1309.470 FPS
6547 frames in 5.0 seconds = 1309.399 FPS
6545 frames in 5.0 seconds = 1308.945 FPS
6544 frames in 5.0 seconds = 1308.787 FPS
6527 frames in 5.0 seconds = 1305.391 FPS
6527 frames in 5.0 seconds = 1305.336 FPS
