Memory allocation with 32-bit OS and 4GB Ram

I've got 4 GB RAM with WindowsXP MCE and the 3GB switch and large tiles enabled. What is the recommended allocation to Photoshop? Even if 3 GB are used by Photoshop, that still leaves 1 GB for the OS, so is 100% recommended?

The tuning FAQ was unclear with respect to 32 bit OS and 4 GB RAM.

Problem goes away with Vista, but what's best for now?

Thanks!

abclapp wrote:

I've got 4 GB RAM with WindowsXP MCE and the 3GB switch and large tiles enabled. What is the recommended allocation to Photoshop? Even if 3 GB are used by Photoshop, that still leaves 1 GB for the OS, so is 100% recommended?

The tuning FAQ was unclear with respect to 32 bit OS and 4 GB RAM.
Problem goes away with Vista, but what's best for now?

Thanks!

My PS CS2 reports:

Memory available to Photoshop: 1762 MB

And it works fine. When I configured my system (4GB on 32bit) I did it according to a MS KB article that claimed that the switches should be avoided, unless absolutely necessary, due to the overhead. It has been a while and I have lost track of the paper but it all made sense at the time.

Good luck,
Ron

Whatever works for you. If 100% causes problems, work your way down in 5% increments until you find your sweet spot. I use 85% most of the time. If I plan on a heavy session with ID, Illy, PS etc all open at once I may drop that down to 65% or so.