Comment by jsheard
15 days ago
Such is life when built-in laptop displays are now pushing a billion pixels per second, rendering anything on the CPU adds up fast.
Sublime Text spent over a decade tuning their CPU renderer and it still didn't cut it at high resolutions.
https://www.sublimetext.com/blog/articles/hardware-accelerat...
Most of the pixels don't change every second though. Compositors do have damage tracking APIs, so you only need to render that which changed. Scrolling can be mostly offset transforms (browsers do that, they'd be unbearably slow otherwise).
That’s not the slow part. The slow part is moving any data at all to the GPU - doesn’t super matter if it’s a megabyte or a kilobyte. And you need it there anyway, because that’s what the display is attached to.
Now, the situation is that your display is directly attached to a humongously overpowered beefcake of a coprocessor (the GPU), which is hyper-optimized for calculating pixel stuff, and it can do it orders of magnitude faster than you can tell it manually how to update even a single pixel.
Not using it is silly when you look at it that way.
I'm kinda weirded out by the fact that their renderer takes 3ms on a desktop graphics card that is capable of rendering way more demanding 3D scenes in a video game.
Sure, use it. But it very much shouldn't be needed, and if there's a bug keeping you from using it your performance outside video games should still be fine. Your average new frame only changes a couple pixels, and a CPU can copy rectangles at full memory speed.
I have no problem with it squeezing out the last few percent using the GPU.
But look at my CPU charts in the github link upthread. I understand that maybe that's due to the CPU emulating a GPU? But from a thousand feet, that's not viable for a text editor.
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