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Yours3lf / rpi-vk-driver

VK driver for the Raspberry Pi (Broadcom Videocore IV)
MIT License
1.23k stars 70 forks source link

Question regarding Performance Recs / Resolution Wiki Section #18

Closed drudru closed 4 years ago

drudru commented 4 years ago

Hi - first off... this is a really impressive project!

I have a question regarding the Wiki. In the Performance Recomendations, under 'Resolution', you recommend 720p. Can you elaborate on this? Is there a rough threshold?

What if I'm rendering: video, a compositing desktop, or a full-screen game emulator? In some of the examples, I suspect that the HVS (hardware video scaler) can do some of the heavy lifting as well. I haven't dug into the code, but I would bet that you are not interacting with the HVS.

Yours3lf commented 4 years ago

Hi

The max resolution the gpu can render to is 2048x2048 - this is a hard limit. However, in the Videocore IV architecture reference they mention performance specs at 720p. Given that this GPU is rougly on par with an iPhone 4 that’s spot on.

“ A fully configured system will support 720p resolution with 4x multisampling at good frame rates with next generation game content “

So you can use 1080p without issues just scale back the pixel workload. I think composition should be fine but maybe for games you should use 720p.

Not sure how HVS works.

drudru commented 4 years ago

Excellent, thanks. I think I can pull off some simple stuff at 1080p given this.

wrt to HVS, here is a great introduction:

https://blog.benjdoherty.com/2019/05/21/Exploring-Hardware-Compositing-With-the-Raspberry-Pi/

cheers

Yours3lf commented 4 years ago

Sweet, what are you planning on doing btw?

drudru commented 4 years ago

Hi, I have an older Raspberry Pi 3 that I used for retro gaming. I was considering playing with graphics on it. Sort of a repl for shaders. I wanted to test out basic 2d graphics primitives using different algos. So, I would have been taking the system to the max.

:+1: