[Tutorial] Boost Compile Times

Moss · August 24, 2014, 7:27pm

Hi,

After building for quite some time I put together some notes on how to boost compile times for the engine and your game projects. I was able to go from 36 minutes on a complete rebuild to 23 minutes, which is quite a lot by applying only a few tweaks.

You can find the tutorial on the wiki and as post on my blog.

anonymous_user_e17b3a37 · August 26, 2014, 1:58am

Holy ****! Thanks for posting it.

I don’t have a direct comparison at hand, but it made a ridiculous difference on a test scene that had extreme values set in the lightmass.ini. Made it probably 5-10x faster for me.

Pretty confident the difference on low build settings will be rather small, but with extreme settings the speedup seems to quadruple.

Moss · August 26, 2014, 5:20pm

Every thing that is IO bound will benefit from the same approach. Nice that it helped! You could also add your numbers into the wiki post

Robbie222 · September 9, 2015, 11:17am

I honestly cannot find the UnrealBuildTool , I’ve looked everywhere , searched on all my drives.
There is only one I’ve found in C:\Users\Robbie\AppData\Roaming\Unreal Engine\UnrealBuildTool\BuildConfiguration.xml but this only contains : " <?xml version=“1.0” encoding=“UTF-8”?>

-<Configuration xmlns=“https://www.unrealengine.com/BuildConfiguration”>

</Configuration>"

Can anyone help?

Gildor · September 23, 2015, 5:52pm

Check UE4/Engine/Programs/UnrealBuildTool directory. Probably it will be generated when you’ll build your engine.

anonymous_user_f6022ca0 · February 29, 2016, 1:48am

Much like Robbie222, I am unable to find the BuildTool config. I too have a xml file in AppData\Roaming\Unreal Engine\UnrealBuildTool\ which with zero configuration parameters in it.

Additionally, I do not have a “documents” but I do have a “My Documents”, in which there is only an Unreal Projects folder (which is empty).

For 4.10, on a Windows 7 system, where in the world is the engine installed at? Bear in mind I installed the engine from a supplied executable from the site, not a build from source.

CJ31387 · April 17, 2018, 10:11am

Bump, I cant find the file either, was it switched to somewhere else, or does unreal automatically use all cores to build now, or whats the deal.

Gildor · May 20, 2018, 9:46pm

It’s in Engine/Saved/UnrealBuildTool/BuildConfiguration.xml

EDIT: I’ve checked UBT source code, it seems you can control number of parallel tasks (upper value) with BuildConfiguration.xml, “MaxProcessorCount” property.

MrAdom89 · August 25, 2019, 10:20am

Hi All,

I can’t do that in version 4.22. Is “boost” still available?

spacegojira · September 4, 2019, 8:40am

I would like to know that as well.

Moss · September 5, 2019, 9:48am

I guess yes, just check if the BuildConfiguration.xml has the same variables or it might changed in some way.

Cyberglobe · February 16, 2020, 2:59pm

Is a compiled version from source required in order to make this work?
I can’t find the xml file you are refering to.

Moss · February 17, 2020, 9:15am

The file might be in different places depending on the engine version. But I guess you are right, on installed builds you can not specify it => https://github.com/EpicGames/UnrealEngine/blob/6c20d9831a968ad3cb156442bebb41a883e62152/Engine/Source/Programs/UnrealBuildTool/System/XmlConfig.cs#L205

anonymous_user_dba8e8f1 · March 14, 2020, 1:24pm

is there anything update? now i’m using UE 2.24 and i still fould the config.xml C:\Users<my user name>\AppData\Roaming\Unreal Engine\UnrealBuildTool\BuildConfiguration.xml

Moss · March 23, 2020, 9:15am

From the source code it seams that it moved: https://github.com/EpicGames/UnrealEngine/blob/6c20d9831a968ad3cb156442bebb41a883e62152/Engine/Source/Programs/UnrealBuildTool/System/XmlConfig.cs#L223

Now it should be here: AppData/Unreal Engine/UnrealBuildTool