Re: Backplot issues

[Will Shackleford <shackle-at-cme.nist.gov>]

Paul wrote:

> 
> Hi Ray
> 
> Make sure you have the Mesa-devel package installed....
> 
> So far, I've been unable to repeat the core dump - It might have been a one off.
> But, running a few simulations at work with the Task Manager monitoring the
> memory usage - Once emcplot3d starts hogging more than ~80Mb, there is a
> serious impact on system performance !
> I haven't looked at the source code yet, but I would think some improved data
> compression is called for. (never did get to the end of cds.ngc)
> 
> Regards, Paul
> 
> 
> On Tue, 12 Jun 2001, Ray wrote:
> 
> 
>>I tried making that plotter also but got the message that it couldn't find
>>-lglut.
>>
> 


It has  a tendancy to look like it is hung when it is not really. The
screen doesn't get refreshed unless it recieves a key stroke or an NML 
message. It won't recieve any NML messages if the EMC controller isn't 
running.  It should
display once without a key stroke regardless but especially with larger 
programs often doesn't. So there is a need to hit an arrow key  or the 
space bar to force a screen refresh. If you <alt><tab> to another 
application while running emcplot3d and <alt><tab> back it leaves an 
impression of the other app in emcplot3d which doesn't get cleared until 
a key stroke refreshes the screen.


If it connects to emc it will refresh the screen about every 200 
milliseconds, this partially eliminates the need to send extra 
keystrokes but it means it will take more CPU cycles.
On my 500MHz PC with no 3D accellerator, this was taking 22% of the CPU 
time. You can reduce this by adding "--refresh 100 --timer 100", the 
units are (20 milliseconds) so this reduces the refreshes to every other 
second. You can also add this without connecting to EMC which means when 
it recieves key strokes, it won't refresh as you slide the plot more 
frequently than every 2 seconds, which means jumpier motion but using 
fewer CPU cycles.


It looks to me like top was showing  it only takes 8Mb of memory not 80Mb.


-- Will







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