[OpenLayers-Users] Performance?

[Jeff Dege]

Is there some fundamental reason why accessing MapServer maps through
OpenLayers is so much slower than doing so using either MapServer's CGI
or scripting interfaces?

I'm experimenting with a moderate data set - seven shape files, largest
is 150MB.  When I ask MapServer's CGI executable to draw me a map, it
takes a couple of seconds.  The MapScript DLL is even faster, despite
being asked to do more.

But OpenLayers can take forever - upwards of sixty seconds, sometimes,
to draw a map of the same size.

I've tried Ka-Map (directly, I've not been able to get the Ka-Map layer
within OpenLayers to work), and while it redraws cached tiles quickly,
it's only moderately faster than OpenLayers at drawing them in the first
place.

Is this normal?

What can I do to fix it?