Legacy ImageMagick Discussions Archive

An RMagick user is reporting significantly larger memory usage when running on a 64-bit server vs. a 32-bit server. I believe these are both Intel machines running some flavor of Linux. The method that appears to be sucking up all the memory is ImageToBlob. With a 2000x1000 image in GIF format, the ImageToBlob method uses 2 1/2 times as much memory on the 64-bit machine. The user has configured ImageMagick to use QuantumDepth=8 on both machines.

While I would expect some small change just to account for 64-bit pointers, I would guess that the common quantum depth would make the image roughly the same size.

Do you have any insight into this problem? Any questions I should ask the user to help understand the problem?

A quantum depth of 8 produces the same size pixel cache on a 32 or 64-bit OS. Unsigned long arrays consume twice as much memory on a 64-bit OS compared to that of a 32-bit system. We suspect the extra memory is consumed by the color reduction algorithm that utilizes unsigned long and long double arrays.

Thanks for your answer. I'll pass this info onto the user.

Actually I am the "user". What I find a little weird: When you save the image to disk (instead of doinf to_blob) it does not consume the memory?!
Logically?
Till