Raspberry Pi interview: Eben Upton reveals all (Linux User) [LWN.net]

Raspberry Pi interview: Eben Upton reveals all (Linux User)

Posted Mar 6, 2012 19:25 UTC (Tue) by gmaxwell (guest, #30048)
In reply to: Raspberry Pi interview: Eben Upton reveals all (Linux User) by jzbiciak
Parent article: Raspberry Pi interview: Eben Upton reveals all (Linux User)

"is almost like the ZX81 of our generation"

Except for the fact that that most of the transistors in the main chip are locked up in a completely proprietary DSP which is why the devices needs an 18MByte binary blob to even boot.

...and the ARM CPU (really a coprocessor) is anemic enough that without this DSP there is basically no hope of reasonable video decoding on this platform.

Pretty lame from the perspective of an expirementer's platform, really.

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Raspberry Pi interview: Eben Upton reveals all (Linux User)

Posted Mar 9, 2012 22:16 UTC (Fri) by WolfWings (subscriber, #56790) [Link]

The same description can be given to many thousand-dollar laptops I know regarding the CPU: Video decoding is wildly inefficient on the CPU versus the GPU/DSP, that's the nature of the beast. And, in fact, what GPUs/DSPs are created to assist with anyways. I've played 1080p video on my laptop with the CPU sitting at 800Mhz and all but one core switched off specifically because the GPU did it, if I used a software-decoder the system barely survives at 2*2.0Ghz chugging away.

CPUs are general purpose, but that doesn't mean they're maximally efficient for all workloads, especially insanely parallel ones like video decode/3D rendering.