[IDV #STG-449976]: IDV - "optimum" configuration

HP-

> Institution: EUMETSAT
> Package Version: 2.1b1
> Operating System: os.name:Windows XP; os.arch:x86; os.version:5.1;
> Hardware Information: java.vendor:Sun Microsystems Inc.; 
> java.version:1.5.0_06; java.home:C:\\Program Files\\IDV_2.1b1\\jre; 
> j3d.version:1.3.2 fcs (build12); j3d.vendor:Sun Microsystems, Inc.; 
> j3d.renderer:OpenGL;
> Inquiry: Hi
> 
> Every now and then IDV aborts when handling a couple of larger data sets.
> I remeber having seen once something about heap size flashing at me before 
> abort.
> I have been looking in the documentation for some hints about
> "optimum" configration of memory use and the like, but was not very 
> successful.
> Can you give any guidance in general and perhaps also for my is M$ XP T43b
> ex-IBM notebook with 1MB of RAM.

The best (only?) reference is in the FAQ:

http://www.unidata.ucar.edu/software/idv/docs/userguide/Faq.html#faq1_cat3_12

512m is probably best for a Windows system with 1 Gb of RAM.  Windows
takes up half of that anyway and once Windows has to start swapping,
performance severely degrades.  On a Linux system, you can probably
get away with 700m for 1 Gb of memory as it does a much better
job of swapping.  All this also depends on what else you are running
on the machine and how much memory it takes.  On my XP system, sometimes
Firefox ends up eating up > 120 Mb which affects my IDV.

For a 2Gb system, you can probably allocate 1.5 Gb to the IDV.

I think for the next release, it would be good to have a page on
performance tuning.  There are several other things you can do to
reduce memory consumption:

- turn off in memory caching - if you are only displaying/using an
image once (i.e. not using it for multiple calcuations), you can
keep from caching in memory.  With caching on, we keep a copy of
the image in memory for future access (true for grids as well).
- set the max image size that will be displayed.  This will allow
you to download a large image, but it will be resampled before
displaying if it is larger than the max pixel size you have asked
for.
(both of these options are under the Data and Formats tab of the
Preferences dialog)

- Turn on Fast Rendering.  This will create displays without accounting
for projection seams which uses more memory.  If you are displaying
the data in it's native projection, you can probably get away with
this.  If you run into problems (i.e. bad displays), let us know.
Satellite projections are tricky and this may not always work.  However,
we can look into any problems you find.  This option is available
in the Preferences also.

So now, I can just take this and put it in the user's guide. ;-)

Don Murray



Ticket Details
===================
Ticket ID: STG-449976
Department: Support IDV
Priority: Normal
Status: Open