That's the problem I think. He's changed from a shared pixel memory in the reference design to a non shared one in his HW accelerated design. That's the impression I get from the diagrams.
It's somewhat moving the goal posts IMO. Guess it's ok since it's a student project.
Pixels are mapped to memory locations, but they don't have to be, if you can access the map directly. I don't exactly know what I'm talking about here, just a thought.
What would be the difference between writing to shared hardware pixels over a shared memory performance wise?
I mean, pixels are just like a memory except that they glow. They hold their value and can be writen a new value in sync with a clock (which is normally 60 Hz for most monitors which is MUCH slower then on chip memory). There could be no performance benefit.
It's somewhat moving the goal posts IMO. Guess it's ok since it's a student project.