So it must be a video card thing then. In the end I remade the routine so that it wrote to an image then I called DrawImage instead of using lockbuffer backbuffer() this dropped the time to 0-1 ms.
I think PGFs speculation could be corect but obviously it varies depending on video card. I'll try the refresh rate test later AND I'll time how long flip and flip false take to see if they are 0ms which would point at the actuall vwait happening elsewhere!
Then there's the point I made about the time suddenly going up to 13ms after a certain number of draw commands, it doesn't matter what they are.
I think PGFs speculation could be corect but obviously it varies depending on video card. I'll try the refresh rate test later AND I'll time how long flip and flip false take to see if they are 0ms which would point at the actuall vwait happening elsewhere!
Then there's the point I made about the time suddenly going up to 13ms after a certain number of draw commands, it doesn't matter what they are.