G,

I don't recall making such a recommendation, but I have quoted advice from Russell Williams in a few threads.

See this version from the Windows forum (it's in here as well somewhere)

Ian Lyons "PS 8 Photomerge and RAM" 1/3/04 10:25am </cgi-bin/webx?13/14>

It "may" seem like Adobe can't make their mind up on this either, but that seems to be more down to what 100% actually means within the Prefs dialog. Some things that might help you better understand:

1. Photoshop can't use more memory than allocated.

2. Photoshop makes a poor guess at FREE memory based on the installed amount up to 2GB (hence Yegors table). By poor I mean it thinks it has more than it really has. Not by much but it can be enough fair you to get into trouble.

3. If you set 100% then Photoshop can use ALL of the amount guessed at in 2 above.

4. Photoshop can't work beyond the 2GB limit. So setting 100% means that less than 200MB is available for those Photoshop features that operate outside the prefs allocation (some plugins and filters - includes those from Adobe but can't recall which).

The bottom line is that with more than 2GB of ram you can set 100% and you'll therefore give Photoshop around 1850MB to work with. However, be careful that the plugins and filters mentioned in 4 above don't come into play. Given the number of differing opinions coming forth I would (only on boxes with more than 2GB) tend to air on the safe side and set the Photoshop allocation to no more than 95%. No doubt there will be differing opinions, but that doesn't mean they're any more/less correct then me/you or my neighbors pet labrador. I think the following is a more reasoned way of determining the best setting:

Originally Posted by Scott Byer on Windows forum

Tuning Photoshop CS:

Open Activity Monitor. Go to the System Memory tab. The number to watch is "FREE". Better still use X Resource Graph ( <http://www.starcoder.com/xrg/> ) and read Availbe in lieu of Free.

[Originally Posted by Scott Byer]

Start Photoshop and start working. That FREE number will decrease and, after a while, will often stabilize out.

Is it below 15000 (15MB)? Your Photoshop memory percentage is set too high. Lower it and try again.
Is it above 50000 (50MB)? If you really have been doing things you normally do, including running a filter and you still have more than 50MB free, you're probably leaving a little performance on the table (but not as much as you think!). Consider increasing Photoshop's memory percentage slightly.

If you *really* want to get technical about it, bring up Performance Monitor and set it up to track a few things (free memory, disk activity, memory paging rates).

What you are trying to avoid is having the OS page out Photoshop's memory. We don't lock down Photoshop's memory because that causes many, many more problems than it solves. But when Photoshop has allocated a lot of memory, some of it looks to the OS as "not busy" and will get paged out if RAM gets low. If Photoshop's scratch and the OS paging file are on the same physical disk, this is doubly bad.

Yegor_Hovakimyan

Replied in the following topics

Photoshop CS Memory Doesn't Match To Installed