   Running two pixel shader programs brings frame dropping
  I used pixel shader to put some postprocessing on the video.Then I tested running two programs at the same time.Each program uses SetPixelShader(...) every time when a new frame comes, or else the shader effect would lose. (maybe replaced by the other program)It came out to be with some stutters and frame droppings.But the total computation burden is not that big.Maybe the pipeline is busy replacing with new shader.So, it seems that if other program running on customers'' pc also uses pixel shader, my program would become not as good as it is.But I think the case is rare, just like watching two film at the same time. 
  Are you saying that you''re running two copies of your application?  If so, why?  Is it just to see how it performs?If this is the case, it''s not surprising that running two apps will slow your machine down.  They''re both vying for time to execute their instructions on the graphics card.  Since only one program can run on the graphics card at a time, Windows has to perform many context switches (stop executing one program and start another).  This takes a lot of time for intensive applications.neneboricua ;  Umm...why would anyone want to run two 3D apps at the same time...? ;quote:Original post by Cypher19    Umm...why would anyone want to run two 3D apps at the same time...?   DirectX apps aren't necessarily 3D apps. The "idea" behind something like DirectX is providing a hardware abstraction layer for multimedia applications.For example, the user could be running a shell/app_whose_GUI utilizes Direct3D and ps2, and at the same time running a modeler/vector_image_drawing/whatever utility that utilizes Direct3D.If you've tried DesktopDreamscapes, at SuperXStudios, you'll see how things are evolving. That's an animated desktop...some sort of a space opera, running all the time, utilizing DX8.1When you stop thinking of DirectX as a game toolkit, and start thinking of it as a multimedia toolkit, you'll realize where we can go. There should be nothing preventing me from using Direct3D instead of, say, GDI+. It'd be loads faster, and with loads more features (if the hardware features were utilized).A problem with DirectX is that it's geared a lot towards game development. It's been said that microsoft is working on fixing this stuff with DX-Next and longhorn. We'll see what happen, then (2006-2007).   Muhammad Haggag [edit]Corrections[/edit]   [edited by - Coder on February 12, 2004 8:21:10 AM]