[gradsusr] How to control the cache size

Jennifer M Adams jadams21 at gmu.edu
Sat Jan 21 11:55:16 EST 2023

The link in the warning is old (oops) here is the right URL: http://cola.gmu.edu/grads/gadoc/compression.html.
Add a line to your descriptor file such as:


The first one is 2x the size of a chunk, the second is 4x. The larger your cache the faster your repeated data requests will be. Set the size depending on how much memory you have on your system. Those arguments are in bytes.

From: gradsusr <gradsusr-bounces at gradsusr.org> on behalf of Muhammad Dogar <mubashardogar at gmail.com>
Sent: Friday, January 20, 2023 3:06 AM
To: gradsusr <gradsusr at gradsusr.org>
Cc: dogar at ees.hokudai.ac.jp <dogar at ees.hokudai.ac.jp>
Subject: [gradsusr] How to control the cache size

Dear GrADS users,

I am using the GrADS Version 2.1.a3. I am working on the output of the GFDL-CM2.1 coupled model. After opening the file, I got the following warning when I displayed the geopotential height variable. I tried to set the cache size scale factor up to 100 in my terminal (i.e., set cachesf 100), however I still got the same error message. Could you suggest some solution? I am not sure if my system is really allocating this size or this version of the GrADS is not handling the memory size properly.

*** WARNING! ***
*** The I/O for this variable will be extremely slow
*** because the chunks are too big to fit in the cache
*** chunk size = 1296000 bytes  (144 * 90 * 25 * 1 * 4 bytes)
*** cache size = 103680 bytes
*** There are two ways to control the cache size:
*** add a CACHESIZE entry to the descriptor file
*** or change the cache size scale factor with 'set cachesf'
*** Please read http://iges.org/grads/gadoc/compression.html<https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Figes.org%2Fgrads%2Fgadoc%2Fcompression.html&data=05%7C01%7Cjadams21%40gmu.edu%7C275ccd748c044bddd40308dafabdbb57%7C9e857255df574c47a0c00546460380cb%7C0%7C0%7C638097990062518452%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=Bmaj0Ya4Sn1uy9XRmwS5MWgOFlQuwTuoZ2IuU5%2FunFQ%3D&reserved=0>
Contouring: 0 to 5000 interval 500

Best regards,
Dr. Mubashar


Scientific Officer (Climatology Section),
Global Change Impact Studies Centre (GCISC)
Ministry of Climate Change (MoCC)
6th Floor, Emigration Tower, G 8/1, Islamabad, Pakistan
email: mubashardogar at gmail.com<mailto:mubashardogar at gmail.com>
           mubashardogar at yahoo.com<mailto:mubashardogar at yahoo.com>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gradsusr.org/pipermail/gradsusr/attachments/20230121/4aa42fc8/attachment.html>

More information about the gradsusr mailing list