:: How to Setup the 3GB switch ::

[Candelero]

In order to help our users, here is how the 3GB switch can be setup.
This has been discussed a lot in the forum, though there are still users finding problems with it.

First, an additional line has to be added in the < boot.ini > file.

The < boot.ini > file is actually a protected system file, which is
hidden from the Windows OS by default. To make it accessible:

• (*) Open the Explorer ;
  (*) Tools - Folder Option ;
  (*) View - Tab ;
  (*) Uncheck the < Hide protected operating system files > ;
  (*) Look for the < boot.ini > in the C:\ root folder ;
  (*) Open it using Notepad.exe (or any other editing application) ;
  (*) Copy the last line, which ends with "... /fastdetect" ;
  (*) Paste it in a new line and replace that with "... /3GB" ;
  (*) You may want to add some text between the brackets, to know which Windows is the one with the 3GB ;

Here is a typical < boot.ini > and how it looks like:

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

Important:

There are some CPU and MB configurations, which also do not allow this extension to run properly.
If you have encountered this, please report the hardware specifications.
Thank you !

For more info on the topic, refer to:
http://www.microsoft.com/whdc/system...AE/PAEmem.mspx


Best regards,
nikki Candelero

[jujubee]

It should be noted that extra precaution should be used if you have a system with partitions on it.

[CXStudios]

We had set this up on our older machines at my previous job, and we came across a problem with removing the 3GB Switch, err.... turning off per say. I don't need to know it now, but others may be in need later on. Is there a way to remove it, if needed?

[percydaman]

We had set this up on our older machines at my previous job, and we came across a problem with removing the 3GB Switch, err.... turning off per say. I don't need to know it now, but others may be in need later on. Is there a way to remove it, if needed?

yes just go back into the boot.ini and remove the entire /3gb line.

[RErender]

that is the point of having the 2 options under [operating systems] that way you have the choice. Whichever one is on top will be the default.

[CXStudios]

That's where ours must have been different. The version of the switch our guy found didn't allow for the choice at bootup, it was just set.... or he did it wrong Thanks!

[Candelero]

It should be noted that extra precaution should be used if you have a system with partitions on it.

Sure !

My personal PC at home has 2 partions and is working fine with the 3GB.
Tested on some other PCs with 3 partions, also no problems so far.

Best regards,
nikki Candelero

[dimo]

Hi,

just wanted to report about the problems we had with 3GB switch. Some of our new workstations with dual Xeon HT and Geforce7800 had a big drop in DirectX graphic performance as soon as the switch was activated. It seemed that the caching of meshes would not work any more. The solution to this was to add an option in the switch that slightly reduces the amount of RAM. The option is /USERVA = amount of RAM.

Here's the line if directX is slower with the switch.

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Micro soft Windows XP Professional 3gb" /noexecute=optin /fastdetect /3GB /USERVA=2816

We didn't test with latest nVidia drivers. Perhaps this problem is already solved. But I thought I should share this here.

Best Regards,
Dieter

[snorthul]

I cannot get the switch to work. I have a Dell Dimension 8300.

3.0 Gig Intel processor (Hyperthreading enabled)
Radeon 9800 Pro AGP 128 Megabyte
2 Hard Drives...one partitioned They are non compressed NTFS
XP Pro Service Pack 2

Dell Bios. Not sure of the Motherboard configuration, although I have been told that Dells don't do the switch.

I really had a problem when I was submitting a 3D render for the Elemental book. I had to do strips and then composit them in Photoshop at print resolution. A real pain.

If anyone can help me get this working, I'd really appreciate it.

[Candelero]

I am afraid that can happen to NOT be possible (because of the DELL).
priad had some similar issue.

Best regards,
nikki Candelero

[gilicom]

who needs to make the 3gb switch?
Only on machines with more then 2gb ram?
do i need to make it on nodes with only 1gb ram?
Gili

[mike.edel]

using the /3gb switch would allow your nodes to use 3gb per process, even if that means they would swap to disk (sloooooow)
i guess it wouldnt make sense on machines with 1gb of ram though (swapping for additional 2gigs of ram would bring down everything to a crawl)

the machine would probably crash befor reaching the 2gig per process limit anyway

[Candelero]

using the /3gb switch would allow your nodes to use 3gb per process, even if that means they would swap to disk (sloooooow)
i guess it wouldnt make sense on machines with 1gb of ram though (swapping for additional 2gigs of ram would bring down everything to a crawl)

the machine would probably crash befor reaching the 2gig per process limit anyway

That is not actually correct.
I have tried this on machines with 1GB physical RAM installed (2x512) and it
DOES makes difference.

Best regards,
nikki Candelero

[mike.edel]

ok, point taken...

i guess it makes a difference in terms of "does it crash or does it render"
but i can imagine the scene would render a lot slower than on machines with more memory

did you manage to have a memory usage of 3 gigs on a 1GB machine? i really dont want to imagine the swapping thats going on

[Candelero]

ok, point taken...

i guess it makes a difference in terms of "does it crash or does it render"
but i can imagine the scene would render a lot slower than on machines with more memory

did you manage to have a memory usage of 3 gigs on a 1GB machine? i really dont want to imagine the swapping thats going on

Correct !

It doesn't crash and it keeps rendering. Of course 2GB will take advantages.
What's happening with the swapping you can imagine yourself.

Best regards,
nikki Candelero