Simple! guide to the 3Gb enabler

Map Maker: ,

Boring technical background:

The 3GB enabler is of script popular for games from the ~2006 era. This point in time marked a transition point as games ram requirements expanded to around 2GiB, a key limitation in 32bit Windows.  In 32bit systems the maximum amount of processor addressable space is 4GiB. In early 32bit versions of windows this space is split equally with Windows getting %50 and everything else getting the remaining %50.

As applications started becoming larger Microsoft made the limit more flexible giving Windows a smaller portion of the pie. Unfortunately this is not as simple as it should have been since many Windows Applications relied on this 2GiB cap. In order to maintain support for these programs Microsoft added a special value that programs could use to tell Windows that it is okay to give said program more than 2GiB.

What the 3GB Enabler does is add this special value to SMR’s railroads.exe which tells Windows to allow railroads.exe to use upto 4GiB of RAM.

Real Introduction:

Now this explanation is rather complex and might not interest you, the handsome, pragmatic user, who simply wants to play those large, awesome, custom maps available for download in the Map Database.

Fear not for I bring you a Simple! step by step guide complete with conditionals and my vain attempts at humor (Yes that is correct, I am not above self-deprecation).

Step 0:

Does your computer only have 2GB or RAM? Does your video card have ~2GB or RAM? Is SMR crashing with the stock maps?

If you said yes to any of these questions the 3Gb enabler cannot help you. I’m sorry but in order to enable more RAM you at least  need to have this more RAM stuff. In the case of high end video cards much of the extra space in 32bit address limit is being used up by the video card’s RAM. Lastly if SMR is failing to play the original maps this is indicates that some other bug is present.

You will not suffer any negative effects from the 3Gb Enabler but it does not bring any benifit.

Step 1:

Check if you have a 32bit or 64bit version of Windows, instructions courtesy of Microsoft:

To find out if your computer is running 32-bit or 64-bit Windows, do the following:

  1. Open System by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Maintenance, and then clicking System.
  2. Under System, you can view the system type.

Step 2:

If you have a 32bit version of Windows XP you must do this:

Manually edit your boot.ini file by adding ” /3GB /Userva=2900″ to your boot.ini (no quotes).
Your boot.ini is normally read only and you will need to change that temporarily while you edit it.
To do this, right-click the file and untick “Read Only”. After editing the file, restore the Read-only status.
To Edit it manually you can find it on the root of your system drive or
go to system properties/advanced tab, settings under ‘startup and recovery’ section, then hit edit.

Mine looks like:  multi(0)disk(0)rdisk(0)partition(1)\WINDOWS=”Windows XP Professional” /FASTDETECT /NOEXECUTE=OPTIN /3GB /Userva=2900

Step 3:

If you have a 32bit version of Windows Vista or Windows 7 you must:

Go to the start menu and in the search box type ‘cmd’, don’t hit enter. Wait until ‘cmd.exe.’ appears on the menu and then right click and select “run as administrator”. Then run this command:  BCDEDIT.EXE /Set IncreaseUserVa 2900

Step 4:

Download this zip containing the 3GB Enabler script:  This link, right here.

Or download the pre-patched exe and replace the normal Railroads.exe, you may skip to step 5.5 then be done.

Step 5:

Extract the 3GB Enabler into the Sid Meier’s Railroad’s Program Files drictory. On 32bit versions of Windows this will be found at C:\Program Files\2K Games\Firaxis Games\Sid Meier’s Railroads!  In 64bit Windows: C:\Program Files (x86)\2K Games\Firaxis Games\Sid Meier’s Railroads!

Step 5.5:

If you have not already patched SMR to version 1.10 now is the time to do so. Without the 1.10 patch most custom maps will not work and many original maps will randomly crash. The SMR 1.10 patch can be found at Fraxis’ site:

Step 6:

Inside the SMR Program files folder will be the files you extracted in step 5. One of these files is “startme.bat”, double click on this program to run it.

Step 6.1:

Hit the A key to add the large address header. Press any key to continue. You are now down and may close the window, or optional complete the next two steps to verify that the patch worked.

Optional Step 6.2:

When back at the main menu hit ‘V’ to output the headers in text so you can see the values.

Optional Step 6.4:

Now you can check to see if the patch is enabled.  Scroll to the top and look for the section “FILE HEADER VALUES”. Look for a line in that section that says “Application can handle large (>2GB) addresses”.  It’s the tenth line down in that section.  If you see that line then the executable is now enabled for >2GB, you are done.

27 thoughts on “Simple! guide to the 3Gb enabler

  1. Jeff

    Kudos to whoever came up with the 3GB enabler fix! For the first time in years, Railroads is running like it was supposed to on my desktop computer. I could never get it to run on my Windows 7 boxes, and even running it on XP was problematic. But this fix on your website has made the game run great. Smooth graphics and movement, reliable operation and fun gameplay!

  2. Mads

    I’m having some problems with the 3GB enabler, when i run startme.bat and presses a to add the header, I get this error massage:

    EDITBIN: fatal error LNK1104: cannot open file “RailRoads.exe”

    And if i run startme.bat as administrator i get this:

    The Oblivion.exe has not been copied to this folder.

    I’m running 32-bit windows 7.

  3. Warll Post author

    That will occur if the file is not in the correct directory. Check that it is, if it still dos not work then there is a manual guide I can direct you to but it is command line.

  4. rboek4

    I have the same problem as Mads and cant find the solution. Can somebody please help me i like this game

  5. Karsten

    The 3GB enabler we have here was adapted from a version meant for Oblivion, so …

    In the README.txt there is some leftover instruction saying:

    *** Important: First make a backup original of you RailRoads.exe, by renaming the copy to Oblivion.exe.original ***

    This is not helpful, all it really means is keep a copy of the original RailRoads.exe somewhere safe.

    In the STARTME.BAT there is this leftover error message, which is also confusing people:
    echo The Oblivion.exe has not been copied to this folder.

    Perhaps Warll can fix these issues.

  6. Daniel

    Yeah I really should, but I’m soooo lazy. I thought I fixed those though.

  7. OzBoz

    I’ve played this game now for a couple of years on my old XP 32bit machine with no problems whatsoever. Now my new machine (Win7 64bit 12GB RAM) can not handle the larger maps, and half the time, at startup, I get an error message telling me to insert the original disk.

    I have XP mode (64bit) installed on a Windows Virtual PC, and it will not even install there. It tells me I don’t have enough resources to run the program.

    Now I’m wondering if the fix above is applicable to my Win7 64bit machine, and more importantly, where exactly should I be installing SMR. From Win7 or from inside the XP virtual machine?

  8. Kojiro

    when i wrote in cmd “Set IncreaseUserVa 2900” pops up is not defined the environment variable

  9. Brian Preece

    I installed the 3GB enabler and the map loader on my Windows 7 x64 laptop. Everything worked fine for a couple of weeks with the user defined maps, but when I went back to original game maps, SMR crashed. I uninstalled both SMR and the map loader and reinstalled SMR only, but it still crashes. I con’t even play the original game now. What do I do next?

  10. Alf

    I was doing as instructed, but the game still crashes, when I run the map, you can solve my problem?

  11. James Simpson

    I downloaded the 3GEnabler and extracted the files into My Documents folder. I then installed Railroads from the cd into the 3GEnabler folder. I then followed the instructions and I have not had any problems since

  12. Peter Robinson

    Found this wonderful game very recently, long gone are the young days playing tycoon.

    Unfortunately, since playing on a 64 bit Windows 7 machine i get frequent crashes.

    Tried to follow these instructions but i stumble in the same problem mentioned by Mads. Did anyone find a way to fix this?

  13. tom

    this is redic. Im not a computer geek now i bought a game i cant play. this isnt easy unless you know what your doing

  14. Galacticruler

    I think this may be the cause of my RR crashing…
    If I launch a non-custom map the game throws a runtime error in my face and CtDs. I’ve tried launching a custom map and it works fine. So, is it this or not?

  15. Galacticruler

    Nevermind, even those maps are broken too…so maybe its not this…I noticed the crashes when I tried to use RR through steam with a disk install, if that helps.

  16. bibu_poland

    For everyone getting the fatal error LNK1104: cannot open file “RailRoads.exe. This is because even of you are set as an administator in Windows, you need to enable the porgram to modify the Railroads.exe.

    Go to your account in WIndows setting and set it to “Never notify me when:” in the Function settings control of users account (last shortcut in the User accounts.

    Hope this helped.

  17. Cazly

    I also install SMR and SMR Intercontinental, I have done absolutely everything I’ve found on this page and in the forum, and do not get to play Railroads. Some maps opens, but when laying the first section of route, was closed abruptly, and most of the maps do not open them.
    that I can do?
    Thank you.
    Greetings to all.

  18. J

    Love the game, can’t finish longer scenarios (not even trying custom maps yet). Using Windows 7 64-bit, 8gb RAM. I have tried using the patch, and when that didn’t work I tried reloading the original file from Steam and using CFF Explorer to enable >2gb ram. The weird thing is I can use Task Manager when I get crash to desktop and see the Railroads process is using a little under 1gb of RAM.

    SO frustrating, I just bought this game and love it so far but… does anyone know how to fix?

  19. J

    A follow-up question: it just occurred to me that my video graphics card has 1gb RAM. I don’t understand how these things work, but is it possible that’s what’s getting exhausted instead of my system RAM? (But, it’s showing up as the process using RAM in Task Manager) – I don’t know, I’m grasping at straws now.

  20. Nat

    What do I do if I have a steam version which does not have a Railroads.EXE (this location does not exist C:\Program Files (x86)\2K Games\Firaxis Games\Sid Meier’s Railroads )

  21. Manu

    Location running Windows 8 Steam: :\Program Files (x86)\Steam\steamapps\common\Sid Meier’s Railroads

  22. Jon

    Yes that is correct. Unfortunately the current patch, and I have been working with 2K on this, only works with the normal install location.

  23. Amadeu

    I have windows 8.1 which I did not see listed above. Thus what should I do?

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