Plugin to throttle CPU Usage would be very welcomed.

Development Pipeline & Plugins
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1

I am currently using UE4.27.2.

I am not quite happy with the stability of UE5, however I see it as an option for creating photo-realistic worlds in the future. However, Lightmass, without GPU rendering, is ramping up to 100% CPU Usage, no matter which CPU I use. This is Not a Case where i am using Integrated Graphics, and simply cannot handle the load. Only Lightmass, without RayTracing does this. [Standard Lightmass,] Ramps up to 100% CPU usage and for large scenes this is NOT Ok, especially in the summer.

My cooling is working as it should, liquid cooled, idle @ 28-35C, Gaming and benchmarks at 75C.

I have seen CPU Package Temp @92+C, when using Unreal Editor for v.4.27.2’s Lightmass and even before. I am Not happy with potentially losing my CPU and building a new PC simply because RayTracing is not an option that I can use.

A Plugin to Throttle CPU at 80% when using Lightmass, Not GPU Lightmass, would be great, if someone could. Marketplace has room for this code plugin. Thank you.

2

The whole point of Lightmass is to pre-render lighting, and it does this largely by calculating light collisions and radiosity on the CPU.
It uses all of your CPU. That’s what it’s for. That’s the whole reason we have powerful, multi-core CPUs!

If you’re not OK with the CPU using all the cores for cooling purposes, then the problem is with your cooling.
I suggest underclocking the CPU in the BIOS to make it run cooler. This will achieve the throttling and perhaps lifetime improvement you seem to want.

Another option is to build a render farm of machines, perhaps running in the cloud, that you can start up when you need to build lighting. This will farm out rendering work to those machines, and the render swarm manager even lets you set how many threads are run on each of the rendering machines.

3

Lightmass could easily do the same job As An Option, using 80% of your CPU.

I have a 12-core CPU and it is using 10 of them, however, the usage of my CPU in its entirety, is 100%… I see no need to use 100% of your CPU Dangerously, when you could throttle CPU usage to 80%.

I don’t think it’s a cooling issue, more like using too much resources as Mandatory, when some users would prefer a little slower, but much more cautious, with a CPU Throttling plugin.

4

It should not be dangerous to use 100% of available CPU resources. If it is, that is a design defect in the system.

It absolutely is a cooling issue. If it is “dangerous” to fully use the CPU, then the CPU is not getting cooled enough. That is a system problem, not software problem.

Anyway – the solution for you is to down-clock the CPU 20% in the BIOS. Then using 100% of available CPU (which is what software should absolutely do) will run the CPU at 80% load and you’ll get what you want.

Or, to put it another way: You’ll be configuring your CPU to operate within the TDP that your cooling solution can actually support.

5

I’m not underclocking my CPU just to appease 1 (One) single piece of an app that refuses to cooperate; With no option to throttle CPU, it may very well be dangerous in certain climates.

All of my apps and programs, my system, do fine even if going to the 82C line, Windows throttles @ 82C (working as intended here,) but Lightmass does Not throttle at all.

Look, I’m not a paid Developer, and I know my CPU Cooling is solid, however it’s Lightmass that fools the system into not throttling at 82C, when the rest of my system does, so can we stop playing these games? I’m not sure what part of ‘Optional’ you don’t like or want to understand.

6

Imagine if a car said “yes, the brake pedal can go to the bottom, but if you push it more than 80%, the tires will explode.”

Imagine if a light dimmer said “yes, the dimmer can go to 100%, but if you make the light brighter than 80%, it will catch fire.”

There is no such code in Lightmass.

It’s your CPU that is poorly installed. Nobody is going to write custom software to solve that problem for you.

Anyway, I suggested how you can make your system correctly run all possible software, and not just software that chooses to not use the full CPU. If you don’t want to do that, that’s up to you. Good luck making your game!

7

Proof it or stop harassing me.

Plenty of people using Lightmass for Modding games see their CPUs @ 100% and even the Best Professionals cannot solve Heating Issues in Hot climates. Inregards to “tricking your system into not throttling at 82C” … The code simply ignores any Windows Throttling and goes over 82C anyways, you know it, I know it.

IT SHOULD BE OPTIONAL TO THROTTLE YOUR CPU IN LIGHTMASS, It’s simply poorly designed that way. Please stop making excuses.

Allegations that my CPU is improperly installed with not even anecdotal experience with it, except everything else that stresses my CPU at less than 100% does not reach insane temperatures.

You may be thinking, basically Unreal Engine has gone into lumen and nanite, so older versions and those without the aforementioned Lighting technologies don’t mean anything anymore… So no fix for the laughable lack of Optional Throttling, instead, more sales for CPU manufactuerers.

Plenty of people have high temperatures using Lightmass, but oddly enough you’re the only one commenting. Please leave, Thanks.

And just in case, you seem to be the type that sees “Laughable,” “lack,” and Throttling;" However you don’t see the “Optional” probably because you don’t want to.

Level designers for games using Unreal Engine <5 are mostly forced to use Lightmass, Not GPU Lightass, because of lack of RayTracing. These are “Modders” who aren’t paid for their work, and even the Developers of these games need to be cautious.

Also, down-clocking my CPU isn’t a good option for an enthusiast… 99.9% of my apps and system are fine, but for this one malformed app i should downclock just for Lightmass? Sorry, i’m trying to be efficient while still enjoying my system for everything else, i’m not on a dedicated dev workstation.

There are plenty of normal people using their PCs for tons of stuff, including Content Creation, Gaming, Media, etc that suffer from this problem only with Lightmass; All the problem does is turn more people away from Unreal Engine.