We are rendering an arch vis file at a 6000X3000 res.
On the vista machine the memory use when viewing task manager keeps rising all through the render while the XP machine levels out after the radiosity pass is done. The Vista machine crapped out 3 times trying to render the scene. I even rebooted once to make sure I got rid of any gremlins. The XP machine with lower operationg resources system is running a 1.93 GB in task manager. I resized the camera to 4800x2400 in the vista machine and it is using 2.18 GB and still rising.
What is vista doing that it keeps chewing up ram?
I thought vista could use 3.0 Gb of ram versus 2 GB on xp but my first render on the vista machine at the 6000x3000 res only got to 2.05 GB before it crapped out about 3 minutes into the render.
Both machines are q6600 quad cores with 4 GB of ram.
xp machine is running 32 bit windows so it is only seeing 2 gb of ram (no we haven't set the 3GB switch)
The vista machine is running xp home premium I think.
Help please.

Another strange thing was the xp machine was only using about 38% CPU usage under task manager and then it rose to 99% after a period of about 10minutes. The vista machine showwed the cpu's at 100% usage all the time.
We have rendered some scenes taking up to about 3 GB or more on the vista machine before. Not sure what is up with it this time.