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LWN.net Weekly Edition for December 5, 2013
Deadline scheduling: coming soon?
LWN.net Weekly Edition for November 27, 2013
ACPI for ARM?
LWN.net Weekly Edition for November 21, 2013
Time moves on, ya know?
Nothing has been moved
Posted Nov 2, 2012 23:44 UTC (Fri) by Arker (guest, #14205)
And this blunt comparison is a *severe* underestimate of the real difference, because an ARM11 can do a lot more with a clock cycle. That 386 chip didnt even have a floating point unit, let alone tricks like SIMD, branch prediction, out of order completion... clock for clock the ARM chip would still be far more powerful. And that's before you even consider the cache architecture, the system bus... over 500 times the main memory.
I have no doubt at all that if you could get a few thousand of those arm chips in the hands of promising young programmers WITHOUT the fancy GPU to fall back on, one of them would shock you all by making it do things you think are impossible. But if he's told instead he has to use the high level interface and pass OpenGL to a blob he cannot inspect or modify, he'll probably just pass messages until he gets bored, or finds a bug he cant fix, and then move onto something less frustrating than proprietary computing, like playing football with a bunch of guys twice his size or having molars extracted for fun.
Posted Nov 3, 2012 0:19 UTC (Sat) by dlang (✭ supporter ✭, #313)
nobody is disputing that more access would be better, but you are making the assumption that doing new and interesting things with the video is the primary purpose of all users of the device.
It may surprise you that most people who use computers aren't going to try and debug video drivers or firmware, even where they do have that capability. They will usually just download the latest version to see if it's fixed, live with the problem, or revert to a prior version.
We saw this with the Intel video drivers a few years ago, fully open-source drivers, but when there were problems in the drivers in a ubuntu release, 99.999+% of the people just stuck with an older version.
For those people, the difference between a high-level API and a low-level API is meaningless. To be fair, probably 90% of them wouldn't care if the entire driver was a binary blob, but that still leaves a very large group of people who benefit from having all the kernel and userspace stuff being open, even while the firmware is closed and has a high-level API
Posted Nov 3, 2012 15:28 UTC (Sat) by bronson (subscriber, #4806)
On the Pi, the FB is in shared RAM clocked at 400MHz. RAM probably has a bandwidth of around 250MB/sec (wild ass guess based on parts). If you're driving 1080p, that doesn't leave much bandwidth for anything else. Plus ca change, eh?
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