Plug-in request to release memory in Photoshop

Question

Photoshop has never released memory. I read about 10 discussions about it, with entertaining side-steps to virus scanners and video drivers, and it all comes down to the same thing. Photoshop does not release memory. As Adobe knows this since a couple versions back and never patched or updated it in a new release, it would therefore be great if some company could pick up the task to write a plug-in for this. Almost every serious Photoshop user will buy that plugin as the only other option is to buy more memory.
Just a little illustration for newcomers what the problem is. Here's what Photoshop uses according to the task manager:
start Photoshop -> 110mb
open a 2.65gb psb -> 7975mb
close the 2.65gb psb -> still 7975mb
open a different 2.07gb psb -> 10106mb and any edit goes tedious slow because it is partly scratching because it did not release the memory when closing the 2.65gb file. The only solution was that I had to restart Photoshop after I closed the first psb. This is by the way with 16gb ram on win 7 64, where photoshop is assigned 10gb (67%).
The same thing happens if you Automate a Batch because with every opened file the memory never is given back until Photoshop ends up on the scratch disc slowing down to about one third the original speed if it isn't slower.
Anyway, I really hope there are some talented coders out there, using Photoshop, who would want to developer a plug-in. I have 16gb ram in my computer and the only program that uses that is Photoshop. I would have never upgraded my ram if Photoshop released memory.

Answer 1

Why do you think it needs to work differently than it does?  What specific problem are you having?
If you want the best possible Photoshop performance, having it allocate then reuse its own memory (without deallocation) is more efficient than returning it to the operating system, then requesting it again later.  It doesn't sound right at first, but the Adobe engineer Chris Cox has said that they've explicitly tried it the other way and it just doesn't work as well.   Your basic assumption (that Photoshop is doing something wrong) is simply flawed.
Now, if you need your system to be doing a number of RAM-intensive things at the same time, including Photoshop, you have to outfit it with sufficient RAM that it can work with Photoshop using all that you have allowed (in the Performance preferences) PLUS the other RAM usage you anticipate.  In reality, few folks use multiple applications simultaneously that are all RAM-intensive, and those who do simply buy huge amounts of it.  I personally outfitted my system with 48GB and it's never starved for RAM (and I do multitask a lot).
There's little hope for a plug-in that will cause Photoshop to release all of its RAM.   The only way I know of for a plug-in to affect Photoshop's memory usage, and that is to provide a large (up to 2GB because it's a signed 32 bit field) estimate of how much RAM a plug-in will need in the gFilterRecord->bufferSpace field.  That field is 32 bits no matter whether the 32 bit or 64 bit Photoshop is running, so the most a plug-in could possibly ask Photoshop to release (indirectly) is 2GB.
-Noel