Low framerate in stencil reflection


Why my stecilbuffer reflection’s frame rate is very low? Do you think that is normal?
The working file is linked as below:


Just going to take a wild stab at it, but I’m guessing you’re running 16bit color, right? Try 32bit color depth.


I changed to 32 bit. The frame per seconds has been increased. Could you please give me some brief explaination about what are going on?

On some older cards, when running 16bit color, the depth is forced to 16bit. Forces memory into allignment, I think.

No, some older chips can not support stencil in hardware in 16 bit color resolutions because color and depth need to have the same bit count.
You have to switch to 32 bit color resolutions to get pixelformats with 24 bits depth and 8 bits stencil with hardware acceleration on these.

It’s not just on old ones.

If you have 16 bpp desktop, and ask for 8 bit stencil, then you risk getting GDI rasterizer.