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This issue was created automatically from an original Mantis Issue. Further discussion may take place here.

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The CAM raw reader is horrible in parallel. It is horrible from a memory perspective as well as a performance perspective.

My test is as follows:

• Read famip5_ne240b.cam.h3.2001-09-09-03600.nc. This is a parallel reader.
• Enable opacity mapping for surfaces. (I don't think this is the issue).
• Plane (offset left side of screen). Texture map. Clip.
• Plane (offset right side of screen). Texture map. Clip.

Running remote server, performance is as follows:

• 1 cores - 14 seconds final render - 1.58 GB/core
• 2 cores - ?? seconds final render - 1.62 GB/core
• 4 cores - ?? seconds final render - 1.24 GB/core
• 8 cores - 26 seconds final render - 1.04 GB/core (8.45 total)

So, 8 cores runs about half the speed of 1 core, and takes around 6 times as much memory. Ouch!!

Please don't work on this until it has been discussed at a bi-weekly meeting, or you talk to Utkarsh or me.

I have a few more observations, will include them in and additional post.