

How iPhone's GPU works (or why it sucks)? [large video] - dirtyaura
http://media.assembly.org/vod/2009/Seminars/875_iPhone_-_learning_the_ways_of_GPU_from_the_driver_code_h264_1856kbit.mp4

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jerf
Hey, that's over half-a-gig! A warning in the title would be nice, since for
me that's NSFW, albeit in a non-traditional way.

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dirtyaura
Ah, sorry about that. Edited the title

Here is a leaner version with reduced quality:
[http://media.assembly.org/vod/2009/Seminars/875_iPhone_-
_lea...](http://media.assembly.org/vod/2009/Seminars/875_iPhone_-
_learning_the_ways_of_GPU_from_the_driver_code_h264_1024kbit.mp4)

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hypermatt
Intensive technical knowledge, I wish he gave a bit of overview, its getting
long. I'm guessing he figured out how to make it faster or he was just
exploring it the bad driver code.

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nvoorhies
He shows some ways to poke memory managed by the iphone driver and saturate
the gpu using only ~20% of cpu instead of the 64% that you use with the
conventional OpenGLES path.

This necessarily introduces some fragility since you're essentially poking at
magic locations in memory in a totally non-safe manner, but he seems to think
the driver's internal structures are stable enough that this isn't a problem.

In fact, if enough top quality games do this, then the stability might be a
self-fulfilling prophecy, since messing with the driver internal structures'
layout would break all the really nice looking games.

