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0 pointswillis9366y ago0 comments

Right, but display buffering is a solution to the vertical sync issue that has existed for as long as raster graphics. You can’t buy a GPU without it.

Now that I’ve had more time since I read the post, I think they may have been referring to adaptive refresh rate.

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3 comments · 1 top-level

wtallis6y ago· 2 in thread

I don't think adaptive refresh rate is what that post was referring to. Instead, I think it was referring to the difficulty in doing frame synchronization when the game is running on the discrete GPU but the display is connected to the integrated GPU. But I don't know how Apple's hardware is set up on that score.

gumby6y ago

Yeah, the problem was making sure we didn't have screen tearing. T he only path to video was through the mobile integrated graphics interface even when using the external graphics chip. On a desktop CPU you can DMA into graphics memory directly and get the frame sync.

I think you have to do this if you want to be able to switch between integrated and external. Which we didn't care about but perhaps most people do?

wtallis6y ago

> I think you have to do this if you want to be able to switch between integrated and external. Which we didn't care about but perhaps most people do?

Most people need to be able to power down the discrete GPU when they're done gaming in order to have reasonable battery life, and the most user-friendly way to make that possible is for every application but the video game to use the integrated GPU.

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