To be honest I cannot remember how PS runs on XP, its been a while so I can only reference what happens on a Win7 machine.
As far as I do remember though, there is no way, nor has there ever been, any way to segregate any 'temp' files generated by PS into its own 'Temp' folder...it shares the users 'Temp' folder along with every other 'temp' file generated.
The fact you have created a [5GB] partition specifically for 'temp' files and that this is being filled with files solely generated BY Photoshop difficult to believe. Third party extensions can generate many files but I've never known it possible to specify which 'temp' folder, let alone a partition, to use....not via the PS preferences anyway.
As far as scratch disks go, this is used as and when it is needed by PS.
Like any other program, PS only uses the [RAM] memory it needs, up to the maximum allocation you set in the preferences.
If PS needs to use more, (which it more often than not does), than your allocation then it uses the scratch disk as 'temporary' RAM memory.
When PS starts a 'file' is created on the scratch disk to be used as temporary RAM memory.
It is created regardless so that it's immediately accessible the moment its needed...but that is not to say it is always needed, just if.
When PS closes this temporary 'file' is deleted, regardless of whether it was used or not.
The on-going problem with PS is that, amongst other things, it is useless at memory management and therefore may artificially use more RAM than it should, and as a consequence start to use the scratch disk more often than it should.
This is totally independent of any 'temp' files generated, it is one single file created on the scratch disk at PS launch and deleted on PS close.
So to sum up, PS does not use any 'temp' folder exclusively but does use the Windows 'Temp' folder along with every other program.
(Unless there is a hidden preference somewhere in CS3 which I've missed).
The scratch disk is ONLY used once the allocated RAM memory is exhausted, and is used as 'RAM' memory, as a single 'file'.
You are limiting yourself by using the vulnerable XP, (I assume 32bit with the 3GB switch), and also a very old, (10 years), version of PS.
I have no idea why your system is creating so many 'temp' files, but I've never known PS alone to do so....maybe its a quirk of XP.
Regards.
MrToM.
