[Tig] Re: other stuff at IBC?

Sebastian Sylwan sebastian
Tue Sep 24 00:25:31 BST 2002


Hi Rick, Ken, et al.

GSN is an evolution of Hippi. It stands for Gigabit System Network and was 
formerly known as Hippi-6400. It is a parallel interface capable of 
delivering 6400 Mbit/s (hence the name) or 800 Mbytes/s over 30+ meters of 
multipolar copper cable. Considering a 2k frame (full aperture, 
10bit/component, log or lin, doesn't really matter)  is about 12 MB 
(2048*1556*10*3/8) you have a theoretical maximum of 800/12 = ~ 60 fps.
 From theory to practice, though there's usually a gap. It would be hard to 
see more than 780 MB/s from GSN, and there's some overload given by file 
headers, etc.
In the case of debate though my guess is that the machines cannot still 
provide enough data to fill the bandwidth, maybe for lack of internal 
bandwidth even though that seems unlikely (depending on what bus they put 
their networking cards onto) . As far as my knowledge goes there's plenty 
of room in GSN for real time 2k transfers. (If you apply the math to 4k, 
very roughly you should have slightly less than 20 fps at 4k which is circa 
40MB/frame).

Cheers

Sebastian "more background in networking & systems than in film" Sylwan

At 21:22 23-09-02 +0100, Ken Robinson wrote:

>I have to say when I was 'informed' about the Vialta, I was surprised and 
>questioned it.
>
>Re  GSN speeds.... Thomson, anyone????
>
>Ken Robinson
>It is my understanding that GSN is not capable of more than 18 - 20fps. Will
>someone out there in TIG land confirm this?
>
>Rick Harding
>Sony Electronics
>
>-----Original Message-----
>From: Ken Robinson [mailto:crash2010 at yahoo.com]
>Sent: Thursday, September 19, 2002 8:52 AM
>To: Greg Dildine; tig at tig.alegria.com
>Subject: Re: [Tig] Re: other stuff at IBC?

_________________________________________________________________
Sebastian 
Sylwan 
sebastian at vrmmp.it
Direttore Tecnologico - Chief Technology Officer                Tel. 
+390112271211
Virtual Reality & Multi Media Park 
S.p.A.                              http://www.vrmmp.it






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