Halved performance and problems with DualView on nVidia

OpenGL OpenGL: Advanced Coding
1

Is anybody else seeing serious problems with DualView on nVidia?

I am getting halved framerates in GPU-bound programs.

Benchmarking texture download shows the transfer rate to halve (exactly).

Some of nVidia’s own demos don’t work correctly (Timbury shows a black screen + the controls, Clear Sailing runs at about 0.5 fps.)

This is happening on two different computers, with two different boards (GeForce 6800 GT 256MB, QuadroFX 500), with drivers both old and new.

Using the 66.93 drivers I was even getting crashes in a program that worked fine when only a single monitor was active, that was fixed by 67.66 though.

Overall, DualView supports seems very flaky. This is a showstopper for us, if there is no known solution for this we will be going back to all-ATI.

2

Yep… thats true… dualview on NV cards cuts down framerate. But it affect only rendering. Texture transfer should not be affected. I found that newer drivers (66.93) behave better in dualview mode than older one.

I found this in 67.66_ForceWare_Release_65_Notes.pdf

• OpenGL Enhancements
• Improved and more efficient vertex_buffer_object (VBO) handling
• More efficient memory management for improved performance under
DualView

After all, in dualview mode in driver setup pages you can select acceleration on both heads or only on first head. With this you can get speed just like in singleview mode.

yooyo