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How should the /3GB switch be inserted to this boot.ini?

Good Day Experts,

I'm trying to put the /3GB switch into my Winodws XP SP3 workstation and I have this:

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

Does the /3GB switch go at the end, before /noexecute, or before /fastdetect?

FYI - I tried putting it at the end and my system was very slow and glitchy

Many Thanks,

5 Solutions
After the /Fastdetect should be fine.....

What are you trying to accomplish with this? You might be hurting your performance......
Mike ThomasConsultantCommented:
You would normally add this to the end of the line.
Brian PiercePhotographerCommented:
it normally goes at the end - eg
multi(0)disk(0)rdisk(0)partition(2)\WINNT="Microsoft Windows XP Professional" /fastdetect /3GB

In practice it has minimal effect on XP - better to upgrade to a 64 bit system
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The following example shows how to add the /3GB parameter in the Boot.ini file to enable application memory tuning:

[boot loader]
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINNT="????" /3GB

Note: "????" in the previous example can be the programmatic name of any of the following operating system versions:

Windows XP Professional
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
Where on the line it goes really doesn't matter. The problems you experienced are probably because the switch was inappropriate for your situation. Be certain you are doing this for the right reason.

Contrary to popular belief the switch really has nothing to do with how much RAM you have, and very little to do with how it is used. It changes the default virtual address split to 1GB system, 3GB per process. Few applications will benefit from this. The constrained system address space has a number of serious implications that must be considered.

The switch does have legitimate uses but more often than not it is used for the wrong reasons.

This series of articles explains this more fully:

ellsworth2000Author Commented:
This is for Revit Architecture
ellsworth2000Author Commented:
When I add that switch at the end then I'm told that disk hardware problems are preventing me from booting into the OS and then when I go back to the original boot loader then it is fine.
ellsworth2000Author Commented:
that happened cause I took off the /noexecute=optin tho
ellsworth2000Author Commented:
The first time I added the /3GB switch i had some instability but now it seems to work fine as well as Revit isn't crashing.  

Thanks Experts,

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