Confused about the 4gb patch

[hawkhero 11]

Hi, Do I need to add the 4gb patch to FS2004 running in Windows7 with 8gb of ram? Getting reading to do a fresh install of FS2004 on my computer.

[dogtrack 18]

Well, I haven't and it runs fine....150+ FPS.

[Bert Pieke 7,591]

If you are not getting OOM errors, you do not need it.

[dogtrack 18]

If I remember rightly the 4GB patch is for 32bit systems only. Not necessary on 64 bit.

[Luke 782]

Depends on which patch you are referring to. You will need to patch FS9.exe to have it use a 3GB heap instead of 2GB. You do not need to change the Operating System's boot options.

 

Cheers!

Luke

[Jim Young 2,356]

There is no such thing as a "/4GB switch".  It is known as the /3GB switch.  If you have a 64 bit operating system, you do not need it but FS9 will only use up to 4GB's.  If you install a 32 bit operating system, you will need it if you want to use more than 2GB of RAM.  The /3GB switch provides FS9 access up to 3GB's of memory for FS9.  That's the max.  The rest of any memory is used for your operating system functions.

 

Best regards,

Jim

[goates 576]

There is no such thing as a "/4GB switch". It is known as the /3GB switch. If you have a 64 bit operating system, you do not need it but FS9 will only use up to 4GB's. If you install a 32 bit operating system, you will need it if you want to use more than 2GB of RAM. The /3GB switch provides FS9 access up to 3GB's of memory for FS9. That's the max. The rest of any memory is used for your operating system functions. Best regards,Jim

Under 64 bit Windows, 32 bit programs are limited to 2GB of address space unless the application has the large address aware flag set (for compatibility). This is where the 4GB patch comes in. It can set the flag on applications that don't already have it. There is some risk that the program won't handle the large address space correctly though.

[ejoiner 21]

What is this /3GB switch?   I assume this is a command line entry in a short cut or something?  What is the syntax?

[Luke 782]

http://technet.microsoft.com/en-us/library/bb124810(v=exchg.65).aspx

 

Cheers!

Luke

[dogtrack 18]

http://www.ntcore.com/4gb_patch.php

[Reason 20]

I have been suspecting the 4GB switch that patched my fs9.exe on my windows 7 64 bit is one of potential causes of G3D.dll when used together with AES-ed airports. This is what I have found so far searching in the net. But of course I am now still re building my fs9, I will skip 4GB switch per Jim's explanation.

[Luke 782]

Might be worth asking if there are some other users with the same issue. It shouldn't affect FS9 beyond changing a flag in the header, but certain add-ons might not react well to being over the 2GB address.

 

(It's actually why 32-bit Windows operating systems are restricted to 4GB of RAM - they can address 36 bits worth through PAE and the drivers and kernels could have been loaded above 4GB, but certain poorly coded drivers made some bad assumptions on where they were loaded in memory and Microsoft made the restriction.)

 

Cheers!

Luke

[HaraldG 559]

Although I experienced no crashes when I once tried the patch, my FS2004 got extremely slow and stuttering after patching so that I backed up my unpatched FS9.exe. I never had OOMs (excepted when testing Windows without virtual memory), so there is no need for the patch.

 

Cheers, Harald