Imagination PowerVR SDK Blog

Windows Emulation: Greatly reduced OGLES2 MSAA performance


#1

Hello PVR Community,

I’m using the PVR libraries (libEGL.dll and libGLESv2.dll) for windows emulation of OpenGL ES 2.0. This has many advantages including assessment of functionality before deployment onto a hardware platform with Imagination GPU.

I’m using MSAA through the extension: “GL_EXT_multisampled_render_to_texture”

My application with MSAA set to 2 samples runs at half the frame rate with MSAA turned off. My PC is using a nVidia 1070-Ti. Other computers with lesser GPUs will run at 1/10th the frame rate.

I’ve tried a number of the PVR tools including different emulations modes with PVRFrame. I’ve also tried PVRTune but the performance server cannot access GPU data (windows PC is not a PVR GPU).

So I don’t really have any options at this point other than not using MSAA, or living with the reduced performance when using Windows emulation.

Are there any ways to improve “GL_EXT_multisampled_render_to_texture” with Windows?

Thanks and Best Regards,

Jim


#2

Hi Jim,

GL_EXT_multisampled_render_to_texture is not supported on desktop GPUs so it needs to be emulated. This is done blitting into a multi-sample framebuffer. This should be pretty fast as the resolving will be done by the GPU itself. We never have seen a problem as severe as you describe. Have you tried on a different GPU?

Regards.

Carlos.