glBlend issues

All,

I am having problems with drawing glDrawPixels for RGB/RGBA 16 bits (per channel) images. This is using a NVIDIA Quadro (on Windows XP)

The following is quite fast
glDrawPixels(width, height, GL_RGBA, GL_UNSIGNED_SHORT, &raster[0]);

But with blending turned on the performance is really slooow. I thought I could get decent performance with a Quadro!

Are there any workarounds?

Thanks in advance!
Sampo

Yes there is a workaround. Use texture maps instead of glDrawPixels.