[omniORB] Performance Question

[Georg Huettenegger]

I am currently comparing different systems for distributed computing
including VisiBroker/Orbix/OmniOrb.

I am doing a one server to one client scenario locally on one computer and
over a 10Mbit network.

I am sending data types from 1-8 byte and arrays with 1024 byte. These
tests show rather good performance for OmniOrb (especially over the
network, locally on Windows NT DCOM is better and partially VisiBroker).

Recently I added an array (typedef char xx[8192] and typedef char
yy[65536]) to my test and transferred these larger messages (for now just
locally on a Windows NT computer).

With OmniOrb the increase in the needed time for a call is (from 1024 byte
to 8192): 4.78 and (from 8192 to 65536): 7.47
With VisiBroker I get: 1.68 and 6.18;
With Orbix 2.3c I get: 1.23 and 2.54; (with the Orbix values being
initially higher).

These values are not yet commented by Iona or Inprise they are just tries
I made. When my comparison is finished I expect to publish some results.

The source for all systems is the same and I am wondering why OmniOrb does
not keep up its speed when more data is transferred (is the data copied to
often? is the OmniOrb transfer method more likely to be hindered by OS
restrictions?).

Hope somebody can answer my question.

Best Regards,
  Georg Huettenegger