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+-- Forum: PinePhone (https://forum.pine64.org/forumdisplay.php?fid=120)
+--- Forum: General Discussion on PinePhone (https://forum.pine64.org/forumdisplay.php?fid=127)
+--- Thread: 60fps display updates possible without GPU? (/showthread.php?tid=20101)
60fps display updates possible without GPU? - WhiteHexagon - 12-02-2025
I finally got the touch screen working! still some spurious events I need to track down still, including an interrupt flood. But the first thing I added was finger paint mode, to check touch locations, and a button to clear the screen
All good fun, but my 'clear screen' functionality is super slow. I'm guessing at .25s, slow enough to see the progress. This is using a framebuffer approach i.e. no GPU, and a memset to do the clear. But I also tried a direct arm assembly loop, and looks the same.
I dont have enough experience with the PinePhone to know if this is to be expected? or an anomaly in my approach. I was expecting to be able to easily do 60fps with plenty of spare cycles to run my apps.
RE: 60fps display updates possible without GPU? - WhiteHexagon - 12-06-2025
So I found a hacky work-around using some double buffering. I have no idea on performance, but at least I dont see the clear-screen drawing progress now
RE: 60fps display updates possible without GPU? - WhiteHexagon - 12-31-2025
Update: So I finally got the MMU working on the A53! and my clearScreen performance is now around 42x faster
I also found a way to do cycle counting on the chip, and the full screen memset was previously taking 205 million cycles, with the MMU that comes down to 4.8 million cycles. At 24Mhz, I think that equates to .2s, so still not great, but I have no idea what to expect from this SoC...