With enought RAM, what's the point of having a paging file...

of any size at all.

Under win2kp:

I'm under the impression that this os is limited as to how much of the available address space can actually be used. If there is enough RAM (2gb), why have any page file at all?

As I understand it, each process is allowed its own 4Gb address space, of which it can use up to 2Gb of it. This means that you can (even on Windows XP which only supports 4Gb of physical RAM) have more than one process running, each using 2Gb.

You'll definitely still need a page file in this scenario.

To make the failure mode in case you do run out of RAM, less catastrophic.

Peter

...and if you really need lots of memory for applications you can use the /3GB switch in boot.ini to give the applications 3Gb of address space and the OS 1Gb.

(though this only works on the Windows XP, Windows Server 2003, Windows NT 4 Enterprise Edition, Windows 2000 Advanced Server or Datacenter Server and the application needs to know about it to get the extra address space)

http://www.sysinternals.com/ntw2k/info/bootini.shtml

Alternately you can use the /PAE (Physical Address Extention) switch, which turns on 64 bit memory addressing, at least on the W2k Server (not sure which versions) & 2003 Server (Enterprise edition & up). This lets you address >4GB in system RAM, if your motherboard supports it, that is.

-Zeke

From my understanding, some memory management systems have behavior to seek out idle, 'unused' pages of application memory, and put them on disk/swap..

here's something about the Windows NT VMM

I think I'll try XP with the /3GB switch. I didn't think that could be used outside of a server variant of windows. Now to convince the WAN group that I need XP over W2k. They seem to share Tony's distrust of XP.

More than you may want to know:
There are two critical program I'm running, Intralink and Wildfire, both from PTC. They are data managment and cad programs, respectivly.

When importing cad models into the Intralink database, Intralink tends to want to import the whole shebang in one big gulp. Intralink actually calls the cad software in the background to help sort out the model crossreferences. That one big gulp tends to cause a deadlock when the total VM for both exceeds 2GB. It dosen't seem to matter the size of the page file. I've had page files totaling 4GB.

Actually, PAE only increases memory to 36 bits addressable. This is why even with PAE, Intel based x86 servers are stuck at 64 gigs of memory. And unfortunatly it is still only in 4gb chunks, so no one process can use more then 32 bits of memory. It's basicially a hack because 64 but computing kept being pushed off in the mainstream arenas. I hope one day mainstream computing isn't held back by lack of forsight. Take for example another technology that enjoys hitting barriers every year or two, IDE.

More info on PAE here.

Quote:
I think I'll try XP with the /3GB switch.

It only works if your process is /3GB-aware. Most aren't.

Start here for more information. In particular, this.