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0 pointsbaby_souffle4mo ago0 comments

> what does it mean for a GPU to drive a boot sequence

It's a quirk of the broadcom chips that the rpi family uses; the GPU is the first bit of silicon to power up and do things. The GPU specifically is a bit unusual, but the general idea of "smaller thing does initial bring up, then powers up $main_cpu" is not unusual once $main_cpu is ~ powerful enough to run linux.

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throwaway8943454mo ago

That’s interesting, particularly since as far as I can tell, nothing in userland really bothers to make use of its GPU. I would really like to understand why, since I have a whole bunch of Pi’s and it seems like their GPUs can’t be used for much of anything (not really much for transcoding nor for AI).

codeflo4mo ago

> their GPUs can’t be used for much of anything (not really much for transcoding nor for AI)

It's both funny and sad to me that we're at the point where someone would (perhaps even reasonably) describe using the GPU only for the "G" in its name as not "much of anything".

throwaway8943454mo ago

Is video transcoding not “graphics”? Is it doing meaningful graphics work?

kcb4mo ago

The Raspberry Pi GPU has one of the better open source GPU drivers as far as SBCs go. It's limited in performance but its definitely being used for rendering.

regularfry4mo ago

There is a Vulkan API, they can run some compute. At least the 4 and 5 can: https://github.com/jdonald/vulkan-compute-rpi . No idea if it's worth the bus latency though. I'd love to know the answer to that.

I'd also love to see the same done on the Zero 2, where the CPU is far less beefy and the trade-off might go a different way. It's an older generation of GPU though so the same code won't work.

ryandrake4mo ago

One (obscure) example I know of is the RTLSDR-Airband[1] project uses the GPU to do FFT computation on older, less powerful Pis, through the GPU_FFT library[2].

1: https://github.com/rtl-airband/RTLSDR-Airband

2: http://www.aholme.co.uk/GPU_FFT/Main.htm

bitwize4mo ago

You can play Quake on 'em.

j / k navigate · click thread line to collapse

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throwaway8943454mo ago

codeflo4mo ago

> their GPUs can’t be used for much of anything (not really much for transcoding nor for AI)

It's both funny and sad to me that we're at the point where someone would (perhaps even reasonably) describe using the GPU only for the "G" in its name as not "much of anything".

throwaway8943454mo ago

Is video transcoding not “graphics”? Is it doing meaningful graphics work?

kcb4mo ago

The Raspberry Pi GPU has one of the better open source GPU drivers as far as SBCs go. It's limited in performance but its definitely being used for rendering.

regularfry4mo ago

I'd also love to see the same done on the Zero 2, where the CPU is far less beefy and the trade-off might go a different way. It's an older generation of GPU though so the same code won't work.

ryandrake4mo ago

One (obscure) example I know of is the RTLSDR-Airband[1] project uses the GPU to do FFT computation on older, less powerful Pis, through the GPU_FFT library[2].

1: https://github.com/rtl-airband/RTLSDR-Airband

2: http://www.aholme.co.uk/GPU_FFT/Main.htm

bitwize4mo ago

You can play Quake on 'em.

j / k navigate · click thread line to collapse