Out of memory error on an images more than 8000x6000px

[StasV]

Hello!
PI gives out an OUT OF MEMORY error at any operations with the image more than  approximately 8000x6000px
For example, simple operation Pixel Math gets ea error.
When I reduce the image approximately by 10-15 %, all works normally and  PI use  less than 500MB of memory.
Each time, I have a lot of free memory

I made the test. Change memory in the computer: 1G, 2G, 4G
The error does not depend on a real memory.

System:
Win XP 4G Ram
PI 1.06.01.0625

Logs:

PixelMath: Processing view: m2_clone
Writing swap files...
43.92 MB/s
*** Error: Out of memory
Reading swap files...
635.84 MB/s
<* failed *>


StarAlignment: Processing view: m2
m1:
*** Error: Out of memory
<* failed *>

[georg.viehoever]

Hi,

you are not alone with this problem on 32 bit version of Windows, just search for "out of memory" in this forum.

Doing the math, your image should consume something like 550 MBytes=8000pxels*6000pixels*3channels*4bytes, so you would expect that this fits into your RAM. But since you are using a 32 bit OS, Windows at most will give you 3GB (sometimes only 2GB depending on your BIOS) and much of this is fragmented into smaller pieces.

For me, the situation got much better when I changed to Win7 64 bits, which would by my recommendation for you.

Georg

[StasV]

Thanks!
Now I think like you more often

But I do not understand, why there is a threshold size of the image?

I increase the size of the image gradually. And  supervise memory, PI used and OS free memory 
The OS System has a lot of free memory.
Since some size of the image, I get an error suddenly.
On the previous step before a threshold, OS has a lot of free memory

[georg.viehoever]

This is also what I saw: I did not get memory despite the fact that Task manager displayed plenty of emtpy space. The explanation given by Juan usually is that there is still much free space, but no single continuous piece as required by PI. After seeing that Win7-x64 (with the same amount of physical memory) works so much better, I think that this explanation is probably correct.

So if your hardware and your budget permits: Invest in a Win7-x64 license @120$ or so (or go to Linux, as many people on this forum would probably recommend).


Georg