Re: [Discuss-gnuradio] Raspberry Pi Activity?

[Philip Balister]

On 01/17/2013 11:20 AM, Ed Criscuolo wrote:
> On 1/17/13 10:35 AM, Philip Balister wrote:
>> On 01/17/2013 08:57 AM, Ed Criscuolo wrote:
>>> Has anyone been using Gnu Radio on a Raspberry Pi lately? (just got
>>> one for Xmas :) )  Any special build procedures for 3.6.3?
>>
>> Please remember the R-pi is an armv6 based processor with a vfp unit
>> (not a NEON SIMD unit). Do not expect much signal processing performance
>> from this.
>>
>> Armv7 + NEON is much better.
>>
>> Philip
> 
> I thought it has an Arm11!  From Wikipedia:
> 
> "The Raspberry Pi has a Broadcom BCM2835 system on a chip (SoC),[3]
> which includes an ARM1176JZF-S 700 MHz processor.... VideoCore IV
> GPU,[12] and originally shipped with 256 megabytes of RAM, later
> upgraded to 512MB."
> 
> Wikipedia also states:
> 
> "ARM11 is an ARM architecture 32-bit RISC microprocessor family which
> introduced the ARMv6 architectural additions. These include SIMD media
> instructions, multiprocessor support and a new cache architecture."

ARM11 uses armv6 instruction set. Not sure where wikipedia is getting
the SIMD bit from. The Cortex-AX series uses armv7, an updated arm ISA
(instruction set architecture).

> 
> These would seem to imply that the R-Pi has SIMD instructions available.
> 
> In addition, the VideoCore IV GPU looks like it's a pretty capable
> DSP in it's own, capable of running it's own applications without the
> CPU.  Sounds like Volk could take advantage of it as well.
> 

The GPU stuff is most likely closed source, so Volk will not be able to
use it.

Once again, the R-Pi is not an exciting new ARM processor. It is based
on older ARM technology. GNU Radio will run on it, but be prepared to do
a lot of work getting performance out of it. Your time would be better
spent improving GNU Radio on more modern ARM devices such as the
Cortex-A{8,9} processors.

Yes the R-Pi is cheap, but it is not a state of the art ARM device for
doing signal processing work.

Philip

> 
> 
> 
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> 
>