[Paraview] How does results gathering work in parallel rendering?

[chew ping]

Hi all,

I'm doing parallel rendering using 1 client (dual core laptop) and 2 cluster servers (dual core desktop)
below is the timer log result i collected when i run using np4

-----------------------------------------------------------------------------------------------
Local Process
Still Render, 3.029 seconds
Execute vtkMPIMoveData id: 457, 1.98248 seconds


Server, Process 0
Execute vtkFileSeriesReader id: 176, 0.637821 seconds
Execute vtkMPIMoveData id: 457, 1.49186 seconds
Dataserver gathering to 0, 0.829525 seconds
Dataserver sending to client, 0.661658 seconds

Server, Process 1
Execute vtkMPIMoveData id: 457, 0.141821 seconds
Dataserver gathering to 0, 0.141544 seconds

Server, Process 2
Execute vtkMPIMoveData id: 457, 0.243584 seconds
Dataserver gathering to 0, 0.243318 seconds

Server, Process 3
Execute vtkMPIMoveData id: 457, 0.191589 seconds
Dataserver gathering to 0, 0.191303 seconds


-----------------------------------------------------------------------------------------------

 

I notice a relatively 'slow' rendering performance, so i wonder how the results are gathered back and rendered.

 

Case 1,

each process extracts the polygonal data, then send it back to process 0. 

process 0 gather all results, combine with its own, create the final images, then send it to the client

so process 0 is like the one gathering the jig saw puzzle and fixing them, then give the whole thing for the client to render

 

Case 2,

each process extracts the polygonal data, then send it back to process 0. 

process 0 gather all results, then send it to the client, 

the client creates a final image out of pieces of result collected from process 0

so client is the one getting the jig saw puzzle from process 0, fix them and render it

 

 

i'm not sure which case is right or both are wrong, but i do suspect that it will somehow effect the performance because my client has a lower specification compare to the server.

 

 

Any help / reply is highly appreciated!

 

Regards,

chewping

 

 

 

 

 

 

 

 

 
 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.paraview.org/pipermail/paraview/attachments/20091028/a6b45948/attachment.htm>