Legacy ImageMagick Discussions Archive

Hi everyone
I tried to convert some big images tif (more than 1 Gb 16bit of color depth) with convert command.
I want to rotate them 270° and to reduce them in only 8bit color depth.

When I tried it on Ubuntu 13.04 - 4Gb RAM, reading from an USB formatted in FAT32, writing in another USB in FAT32 and temppath set on a temp folder in internal HD - all goes right and all operations required less than 30 seconds per image.
But this was only a test; the real job has required reading from NTFS and (overall) writing on NTFS. So, during the real job, each convertion requires a bit less than 60 seconds. [edited: I've done a big mistake - not 60 minutes, but 60 seconds!!!)

So I think I can try this conv on Windows: I mean that Win7 it's not so time-expensive writing NTFS than Ubuntu.
Result: same machine, booted on Win7: little more than 15 minutes each convertion.
I don't know why this incredible difference between the two OS.
Is there anyone that has ever detected this?

Thank you!

I'm thinking about some different configuration between imagemagick for Linux and for Win.
I'm thinking something like a default configuration more optimized on Linux.
Am I wrong?

Please someone help me!

What version of IM are you using on each system?

How many pixels in your image? If this is (P), you probably need (P*6) bytes of memory. Ubuntu may use less memory than Windows, leaving more available to IM. You may be at a tipping point in running out of memory. The option "-debug cache" might indicate this.

See http://www.imagemagick.org/script/architecture.php for insights.

The image is 17310 x 11310 pixel, 16 bit per channel of depth-color.
I mean I have enough memory.
I have 4 Gb of RAM, and, where I stop some running not-so-useful processes, I think my PC could also make no swap on HD.
What I see is that the PC works to read image - from an external usb drive - than it start to write something on HD.
I've tried to set the temp path on C:\Temp or in C:\users\myuser\Temp, but both time no temp file goes there.
Finally, long long long after, it writes the output image on another external device.

My version is: Now I try to use "-debug cache", as you advise.