Frame times are like pancakes

Time to generate image data, no DMA: 0.015962s

Time to generate data, with DMA to framebuffer: 0.048529s.  That’s not good.

Total amount of data transferred: one 1080p frame — ~8MB.

Measured average latency of 4*16KB DMA puts: 577µs — ~1000 times slower than expected.  Something’s really not right.


First accesses to memory will be more expensive.

Time to generate and DMA first frame: 0.048529s

Time to generate and DMA second frame: 0.016370s

Time to generate and DMA subsequent frames: 0.015944s — slightly faster than with no DMA.

There’s still plenty of work to be done before it’s functional and interesting, but I may yet hit my goal of 60 fps for this project :)