[Arm-netbook] [review] SoC proposal

[Gordan Bobic]

lkcl luke wrote:
> On Thu, Feb 9, 2012 at 7:41 AM, Vladimir Pantelic <vladoman at gmail.com> wrote:
> 
>>>   we evaluated the possibility of coping with 1080p30 video decode, and
>>> worked out that after one of the cores has been forced to deal with
>>> CABAC decode all on its own, the cores could then carry out the
>>> remaining parts of 1080p30 decode in parallel, at about 1ghz, quantity
>>> 4.
>> I would not recommend fully loading the cpu while decoding video, HD
>> video is becoming a commodity and people might soon use it as an "animated"
>> wallpaper while doing other CPU intensive stuff
> 
>  last year the target speed was 1.5ghz, 4 cores.  this time we
> envisage 8 cores at over 1.2ghz, and the cores can be made to support
> VLIW which can result in 3x the effective clock-rate.  so i don't
> think that CPU horsepower is something to worry about.  the only thing
> that's of concern is to not put too _much_ horsepower down so that it
> goes beyond the gate-count budget.

I think you need to look at this from the practical standpoint. 
Specifically:

1) Is there GCC support for this SoC's instruction set, including VLIW, 
SSE, and all the relevant CPU extensions? How many man-hours will it 
take to add reasonably well optimized support for this, and how long 
will it take to stabilize it for production use (i.e. good enough to 
rebuild the entire Linux distro including kernel, glibc, and other 
packages that resort to assembly in places)?

2) How long will it take to add Linux kernel support for this new SoC 
and all of it's features? How many man-hours will that take before it is 
sufficiently tested and stable for an actual product that the end 
consumers can use?

3) How long will it take to add support for this SoC to all important 
packages that use assembly in places?

You might have the hardware out in 18 months' time, but I would be 
pretty amazed if you managed to get the OSS community enthusiastic 
enough about this to get the whole software stack ported in an amount of 
time that is less than years - by which time the SoC will be thoroughly 
deprecated.

Look at the rate of progress Linaro is making, and they have a 
multi-million $ budget to pay people to push things along, and an OSS 
community that already has ARM well boot-strapped and supported.

I think you are underestimating the amount of effort required to make 
this a success. Much as I would really love for it to succeed, I don't 
think it plausibly can - at least if you start with an ARM or MIPS core 
you already have the basic things like the kernel, gcc and glibc sorted. 
Having said all that, I'd love to be proved wrong.

Gordan