Not enough memory (again)

[mikemeister_admin]

Hi there,

This is starting to really frustrate me!  See my earlier posting.

Dell 9200, Core-duo, 2 x 250gb hd, 5gb as the scratch disk on second hd,  just up-graded the memory from 2gb to 3gb (2 x 1gb and 2 x 512mb) and PhotoShop CS3.

80% of the time that I use CM, usually with the Wizard (only applying Brightness and a little colour boost,) I will get a ' Cannot complete the operation, out of system memory (RAM)' message.  So I figured to up-grade the memory to 4gb.  CM flew.  Tried it again with a DVD playing, three of four apps open, Firefox open in the background and my scanner working.  CS3 and CM flew.  Great!

Until I learn that of the 4gb of memory, Windows is only able to use 3gb.  Why waste money, I thought, so returned the 2 x 1gb and replace with 2 x 512mb.  Now I have the max that XP can see (and apparently use) and CM has slowed to a crawl.  Also, the out of memory message is appearing again.

I have PhotoShop performance tab set to 70%, so there should be enough.

Any advice would be really welcome.

Many thanks,

Rex

Up-date.

Have just been playing around and spoken with the Crucial Memory Help Desk (who were very helpful but did not solve the problem.)

I scan 6x7 transparencies and initially save them as about 130mb, 16 bit tiff files.  A file of this size is giving the CM message above.  I usually do whatever adjustments with either PS and/or CM (I like that fact that CM adjustments can be saved to a PS layer) then reduce the file to either  a max. dimension of 420mm (A3) or crop to A3.  This gives a file of either 112mb (420mm) or 99mb, both 16 bit.  This is my hero file. 

In a nutshell; with either 16 bit, 112mb or 99mb file size and 3gb RAM, CM flies.  But a 133mb file and it's a no-no.

Any advice would be really appreciated.

Rex

[derekfountain]

Until I learn that of the 4gb of memory, Windows is only able to use 3gb.  Why waste money, I thought, so returned the 2 x 1gb and replace with 2 x 512mb.  Now I have the max that XP can see (and apparently use) and CM has slowed to a crawl.  Also, the out of memory message is appearing again.

Unfortunately you misunderstood something. Windows can only use 3GB of memory per process, not in total. So Photoshop can use 3GB, but if your system has more it'll be used by other applications, Windows itself, system caches, and so on. So you were in a situation where Photoshop had 3GB all to itself and the rest of the system had 1GB for its own use, and everything was happy. By reducing your system memory down to 3GB you're now expecting Photoshop to share with the rest of the system. Basically, you've reduced the amount of memory that Windows can make available to Photoshop and now Photoshop doesn't have enough for your big files.

I tried an experiment - I created a big file, A3 sized at 360dpi, 16 bit. The New File dialog told me it was 143MB. I created a few layers and filled them with unique content. Task manager said Photoshop was taking 240MB. I then started CM and the Photoshop process slurped up memory very rapidly. By the time CM had got initialised Photoshop was taking nearly 700MB. I'm not sure how CM uses that memory but the usage pattern isn't unique: I started the Unsharp Mask filter in a similar way and that immediately grabbed another 300MB to work with, shooting up to over 700MB by the time I hit Apply. Anyway, when I hit Apply in CM I also got the out of memory error, so it's not something you're doing.

I guess Mike might be able to shed some light on why the filters' memory usage are so high, but in the meantime, short of changing your workflow such that you end up running CM on smaller files, you need to put the extra Gig of memory back.

[-default]

32 bit windows supports 4GB of address space total.  Windows allocates 2GB of that address space to the application, and 2GB to the system.  Your experiments with memory configurations bear this out, with Photoshop and Curvemeister providing adequate performance with 4 GB installed.

There is another approach, which I use occasionally for testing, and that is the /3GB switch in boot.ini.  This switch instructs Windows to allocate 3GB to applications, and 1GB to the System.  On my system, I have been able to use this setting with good effect to open large images.  Here is a reference from Microsoft:
http://technet.microsoft.com/en-us/library/bb124810.aspx


I am enclosing my boot.ini file in case you would like to experiment.  Bear in mind, though, that you must have an independent way to boot your system, so that you can replace the boot.ini if neccessary.  Booting from the windows CD is probably adequate for this.  It is easy to end up with a non-bootable system after changing the boot.ini file!

Photoshop's memory slider does provide some user control over memory allocation, but I have not been able to get a consistent result with setting the slider to smaller values versus larger values.

[-default]

Re curvemeister's use of memory.  Curvemeister does use more memory than most plugins, however it does it's actual image operations using Photoshop's tiled memory architecture, so the memory use is not very dependent on image size.

Photoshop fragments its own memory rather badly during a typical filter operation, and then fails with an out of memory error several seconds after the operation is completed, and Curvemeister has exited.  I do several things under the hood to try to help Photoshop with its memory allocation.

Curvemeister attempts to protect Photoshop from itself by reserving a large block of memory after the Apply button is clicked, and releasing it before returning to Photoshop.  Using this strategy, with CS2, I was able to support file sizes of about 150MB without the /3GB switch (mentioned in my previous post), and considerably larger images with the /3GB switch.

Another variable is background processes, including printer drivers, screen capture utilities, and other system related activities.  Some of these take a slice of user address space and cause some slight memory space fragmentation.  Every little bit helps.