Extreme High Processor Usage when starting latest UE

Hey UE-Team,

I’m fairly new to UE and encountered an issue when starting the new UE 4.26. When starting UE 4.26 at the point of 10% initializing, my processor usage and ventilation goes into unknown spheres :wink: As I find this not really “normal” I terminated the process and I’m “afraid” to let me cpu go up in flames? Or is this common?

I’m a long-term C4D User and I never encountered such high processing (ventilation) issues even when rendering f. e. large/complex scenes or animations.

System Specs: iMac mid 2020, 3,8 Octa-Core i7, 32 GB Ram, Radeon Pro 5500 XT 8GB

Thanks in advance and sunny regards,


Perfectly normal. The first time you run the engine, it will spend some time compiling shaders which will be done on as many cores as possible, as well as building texture data, mesh data etc.

I did notice something different as well though.
I can load anything quixel/kite demo with ease in .25, but in .26 it insta-bursts my 3960x to 100% and often crashes.
I just cant put my finger on why it happens.

IIRC in 4.26, there’s a pull request that allows setting CPU priority for Shader Compiler processes. By default is High instead of Normal, so it crunches shaders faster, but… it might it can give a hard time to CPUs with sub-optimal cooling.

You might try changing this new setting from that pull request.