Speaker Chris Willing
Time 2009-01-21 17:00
Conference LCA2009

QCIF (QPAC name already taken)

Access Grid

  • video conferencing
  • sharing of applications
    • shared web browser
    • shared open office
    • remote sensing
  • screen gets cluttered very quickly
  • lack of screen real estate
    • use more then one screen per site
    • even this may be insufficient

Scaling images down in size may remove details that may be important for some applications. e.g. medical.


  • OptIPuter = Internet Protocol + Optical network
  • eg. 7x5 30” LCD screens.

Simple tiled display


  • number of outputs per graphics cards
  • number of graphics cards you can fit in
  • may need to mix different bus types


  • Use output from multiple machines. Cluster type display

Cluster tiled display

multiple adjacent machines from multiple computers

Rocks distribution

  • great installation program. Builds network for you.
  • Intended for CPU clusters, not display clusters
  • Based on CentOS.
  • Slow release schedule
  • Don’t recommend doing regular updates.
  • No security updates.
  • Doesn’t support more then one graphics card per machine.
  • Network model not ideal for shared graphics, as machines are on private network.
  • multicast only available on private network.

Front end machine

  • does all the controlling
  • connects to private switch for driving displays
  • another network connection to LAN
  • display machines connected to private LAN

Graphics systems


  • Distributed Multihead X
  • Runs applications normally
  • Some limitations of accelerated graphics
  • Limit to number of nodes. Not scalable.


  • Scalable Adaptive Graphics Environment (EVIL)
  • streams pixels
  • put RGB values into buffer
  • SAGE spreads out to machines as required
  • size of buffer, number of machines, number of videos - bandwidth may be a problem
  • Can move video between sites (good)
  • Configuration by hand. Still in development.
  • Configuation automated in Rocks 5)
  • Not really suitable.


  • Clustered GLX (CGLX)
  • Only distributed as a binary RPM for Rocks.

Our solution

Put all computers on LAN

4K = new video format = 4 * HD

SC08 - network only up and running with 4K support on last day (Friday).