I updated my project from version 4.27.2 to 5.0.0 and C++ compilation is taking about twice as long, sometimes longer. This occurs for both compilation from Visual Studio and for Live Coding. Looking at the compilation logs, the main difference appears to be that the number of processes is lower in…

I just upgraded from 5.0.3 to 5.1.1 and have been noticing significantly faster default compilation behavior without making any changes to the build configuration. Not sure if this is related to the engine upgrade, or an environmental factor, but in any case compilation times have reached an accepta…

I noticed the same thing. Task Manager shows Utilization during UE4 compilations as pinned to 100% on all cores (though it still allows for interaction, luckily). UE5 compilation just results in partial usage of all cores. It’s as if they’re no longer supporting hyper threading. Intel Core i7-10700…

Good find! I’m glad it’s not just me. I just checked Task Manager while compiling my UE5 project from Visual Studio and my CPU usage stays in the 20%-40%ish range the whole time. I wonder if the number of processes is a red herring (even though the number is different when comparing UE4 and UE5), …

I think limiting the processes to the number of physical cores certainly influences things. When it has a thread for each logical core, it can at least continue doing work when another thread is waiting for data.

Yeah, either way, I hope there’s either a workaround or Epic is aware of this issue and patches it soon.

Hey there! I am getting the exact same problem. Did you find a solution or it’s still the same? Edit: This solved my problem. <Configuration xmlns="https://www.unrealengine.com/BuildConfiguration"> <ProjectFileGenerator> <Format>VisualStudio2019</Format> </ProjectFileGenerator> …

I just double-checked using the BuildConfiguration.xml settings that you posted, but unfortunately I am still experiencing the same issues as in the original post. (low number of processes used, low CPU usage, total compile time more than double compared to UE4. Tested on the latest version, UE5.0.1 …

Does anyone know if there is an official ticket for this issue? (or if this is a known issue by Epic?) This thread’s been up for 3 months so I would hope that’s enough, but I can try submitting a ticket if that seems like a good idea. Hoping this gets fixed in 5.1.0 …

Relevant Post: [image] UE5 C++ Compile Time is Substantially Longer C++ I’ve upgraded a medium size project to UE5 and we’re seeing substantially higher build times. I’m controlling for as many variables as I can and still seeing significantly worse performance in apples-…

The key part of that post for me was the memory limit. I suppose there are multiple possible bottlenecks. And most were focussed on the parallelactions. It does seem to detect the number of cores and threads correctly, so I didn’t see a need to mess with that. BuildConfiguration>MaxParallelActions c…

So, one thing I noticed is that my “logical cores” where not being used. RC-1290’s pointer to the BuildConfiguration settings led me to bAllCores. Now with this setting my computer is roaring. <?xml version="1.0" encoding="utf-8" ?> 24 true 512000000

Compilation taking twice as long in UE5: Number of processes being limited?

Development Programming & Scripting C++

neofuturelabs (neofuturelabs) August 19, 2022, 4:26am 9

Relevant Post: