[AG-TECH] New hardware specification for AG 2.0?

S.Booth spb at epcc.ed.ac.uk
Thu Feb 20 07:10:06 CST 2003

On Wed, 19 Feb 2003, Osland, CD (Chris)  wrote:

I think we probably all agree that the original HW spec needs updating a

Like Chris I now control my Gentner from the display machine rather than
wasting a complete PC just to control the Gentner. However I now find that
I never have to change the gentner settings unless I am using the telco
connection. Maybe this is because we have perminant mics instead of
desktop mics.

I am still a little wary of dual CPU mobos. I always have to manually
force vic on my dual cpu display machine to only use a single cpu
otherwise I get the sticky window problem as the process keeps being
flipped between cpus. We also find it a bit hit an miss whether a
particular dual cpu mobo works with a particular version of the linux

> As I've mentioned in another thread, we're interested in higher
> resolution video streams - PAL for starters, XGA would also be
> nice - and these will presumably require CPU power, presumably
> in proportion to the area (in pixels).  Therefore, with the
> current video streams being about 110K pixels and requiring
> about 1400/20 = 70 MHz, PAL streams (768x576 = 440K pixels
> will probably require no less than 280 MHz per stream, and 
> XGA (1024x768 = 800K pixels) will require about 500 MHz per
> stream.  This assumes that the encoding algorithms are
> equally [in]efficient, which is probably a false assumption!
> Tests of video streaming with a non-Osprey card showed that
> it was not difficult to use all the power on an AMD 1600,
> so it looks like the higher-res image streams will be able to
> mop up CPU speed upgrades for a few more years!  Mercifully
> it looks as though our usage is likely to be either a large
> number of sites are current resolution, or a small number of
> sites with a few higher res streams.

I'm not sure that you can assume that cpu load goes as screen area
My feeling is that the encoding artifacts are more noticable on a larger
picture so you need a smarter codec that in turn requires more cpu.

I have been playing with the h263+ codec in vic to try and get it to send
large size (704x576) images.  I'm making some progress and have just
sucessfully sent such an image between 2 machines but its still a bit flaky.


|epcc| Dr Stephen P Booth             Project Manager           |epcc|
|epcc| s.booth at epcc.ed.ac.uk          Phone 0131 650 5746       |epcc|

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