Simple PAE Tweak (For 4Gig Ram users)!

[Youri Carma]

How to enable PAE (Physical Address Extension)?

Start--->Run---> type: regedit-->go to:
HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Session Manager/Memory Management.

Make a new DWORD and name it "PhysicalAddressExtension" and put it on"1".

Thats all!


How do I add the 3GB switch to my computer?

Please be aware that the 3GB switch will only improve stability on systems with 2 or more GB of RAM, and running one of the operating systems referenced below. Once the 3GB switch has been activated we recommend setting the Photoshop cache limit to about 80% in the preferences to ensure stable performance.

Adding the 3GB switch is very simple. You first need to locate your machines Boot.ini file which should be located in the root of your main system drive. (Be aware that this file may be hidden and marked as read-only initially.) You will want to open this file in a program such as Notepad to edit it properly.

Before adding the 3GB switch though it is important to note that the switch is very picky, and requires that every device and driver on your system be fully WinXP compatible in order to work at all. If anything in the system is not compatible, Windows will not load at all when restarting with the 3GB switch activated. The only way to then remove the switch from the Boot.ini file so that Windows can load is to either mount the drive in another system and manually change the boot.ini file, or reformat the drive and re-install Windows. Both solutions are far from ideal.

To safely add the 3GB switch we recommend adding a second instance of the OS in the boot.ini, and add the /3GB switch to that second version.


----- default boot.ini without 3GB Switch -----

This is what a default boot.ini file will look like. (This may differ from system to system.)

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Pro"


----- updated boot.ini with 3GB Switch -----

This is what the updated version should look like. Notice the /3GB that has been added to the second instance of the OS line.

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Pro"
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Pro with /3GB" /3GB


Once you have updated your boot.ini file accordingly and have saved the changes, simply restart your system for the changes to take affect. When your system reboots you will be given the option to choose either the standard Windows XP version or the 3GB switch enabled Windows XP version. If you choose the 3GB version and it fails to allow Windows to properly load, just restart your system and you will be given the two options once again, where you can then choose the standard Windows XP version to load. Either way, if it works or doesn't, you can then remove whatever line you don't need in the boot.ini file.


Please note: The 3GB switch is only compatible with the following versions of Microsoft Windows.

- Windows XP Professional (and greater)
- Windows Server 2003
- Windows Server 2003, Enterprise Edition
- Windows Server 2003, Datacenter Edition
- Windows 2000 Advanced Server
- Windows 2000 Datacenter Server
- Windows NT Server 4.0, Enterprise Edition

For a more detailed explanation of the 3GB switch and usage please visit the following page on the Microsoft website.

http://www.microsoft.com/whdc/hwdev/platform/server/PAE/PAEmem.mspx

In addition:

There is currently a known issue with the 3GB switch and Windows XP SP1, that may cause Windows not to start. A supported fix is available from Microsoft, but it is only intended to correct the problem resulting from this specific setup. For more information including download links to this particular fix please visit the following page on the Microsoft website.

http://support.microsoft.com/default.aspx?scid=kb;en-us;328269

This realy works so very curious if it can help some of you out there?

 

[BinarySynapse]

PAE actually slows the system down and causes some instability with drivers that aren't programmed for PAE mode. In fact, I think SP2 completely disabled PAE mode, I could be wrong on that.

 

[pallesen]

In sp2 and later pae is automatically activated when you have dep enabled. It doesn't really slow down much, but it won't give you access to more memory either. Microsoft has crippled the pae kernel to make sure drivers don't break

 

[Youri Carma]

Short: How to REALLY let Photoshop and other programms use more than 2GB ( but less than 4GB ultimate limit) in XP SP 2:

Both things must be done:
1. enable PAE in registry by changing the value from 0 to 1 ( it that has not already been done)

2.add a line in your boot.ini ending with "/3GB" for instance:

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional 3GB Switch" /noexecute=optin /fastdetect /3GB

This realy works so very curious if it can help some of you out there?