Ram max?

[PSpfano]

When I use photoshop I lose 2 or 3 gigs on my hdd, then when I close it I get gigs on my hdd back? In iStat my ram isnt maxed out.

 

[snickelfritz]

Photoshop requires ~5x filesize in disk space for scratch.
This always occurs regardless of the available RAM.
This is why Photoshop Gurus advocate high speed disk arrays for scratch.

 

[LERsince1991]

Whats the Max RAM Ps can actually read? is it 3.2gb or more? I bet with snow leopard its higher for the os but would Ps still be limited?