How do you speed up Unreal?

Hey, I’m a unity dev, I’ve wanted to transition to unreal for a long time, but every time i try I’m put off by the time it takes to load projects, import assets, bake shaders etc.

It feels like everything i try and do in unreal takes 10x longer than what it would in Unity. I’m sure part of that is due to a lack of familiarity with the engine but I was hoping for some advice on what i can do to avoid staring at loading bars for half the time i spend in engine.

If it’s relevant here’s the specs of the build I’m using for unreal:

CPU: Ryzen 5 5600x
RAM: 16 GB 3200mhz DDR4
GPU: 3060 TI
Storage: Samsung 980 NVME M.2 SSD

1 Like

Unreal is always running at top speed, you can’t speed it up.

Don’t you have to import asset in Unity?

Why are building light, do you specifically want to use static lighting?

Hey there @Alexgmate! Welcome to the community! So to get it out of the way at the start, Unreal is significantly heavier than Unity at base as Unity is more of a blank canvas. Unreal comes with a myriad of tools and plugins that allow you to use AAA tier tools on Indie games without having to implement them yourself. This does lead to build times and general editor applications more expensive and time consuming than the blank slate Unity is. To make the engine nearly as bare bones you’d need to cut out lots of plugins strategically. Alternatively UE4 is significantly lighter than UE5 depending if you’ll be using some of the new tech, I still work on 4.23 for one of my projects.

That said, as clockwork you don’t have to use static lighting, so lighting builds don’t need to be as often (unless you’re working on mobile then you might want to use baked lighting). If you do have any questions, don’t hesitate to ask!

1 Like

Hey @Alexgmate! Welcome to the forums!

To add on a bit more, I would suggest that your main issue here would be ram. Unreal takes a bit more so having 32+ Gigs would help out tremendously. Here are a few things you can do help mitigate the stress load.

  1. Disable Lumen and use screenspace instead.
  2. Ensure that you are not using any raytracing.
  3. Make sure you are using low poly assets (some of the assets the Engine can handle are super hefty
  4. Check your lighting settings and make sure you aren’t using anything process heavy.
  5. Double check and make sure you are not running any background processes. They are easier to run while using Unity, so there may be something conflicting with your available RAM.

It’s not an end-all-be-all list, but I hope this helps make your experience better.

1 Like

how long you been using it? a couple days? get familiar with it. it’s actually pretty fast if you know what you doing.

the project load is decent fast. don’t complain.

the shader compiling at project load stops entirely once you locked in your render settings in the project settings. there are a couple of switches that require a complete recompile of all the shaders permutations. get this out of the way first and don’t touch it afterwards.

assets need a bit of optimization when you import them. get used to it. you only do it once per asset. it’ll get stored in optimal form.

shader compilation on the fly depends how expensive and off the standard your materials are. word of advice: create standard sets of material parameters you need often and make it one material/shader and use material instances for materials that use the same parameters. you’ll never recompile those materials/shaders. you just plug in the texture and colors and values, and done. it’s undervalued and often overseen optimization.

1 Like

Yeah, Unreal’s wait times take long compared to Unity. Especially any kind of compilation. Packaging seems similar to Unity.

Increasing the amount of RAM you have CAN help when compiling the engine from source, because it needs a surprising amount if you actually want to make use of all the cores in your CPU.

Comparing editor start for similar projects:
Unity (cold): 24 seconds
Unreal (warm): 22 seconds
Unity (warm): 6 seconds

I don’t know exactly where that’s coming from. I can see that Unreal is loading lots and lots of dlls at the start, so I’ve made a note to check later whether disabling as many plugins as possible might reduce startup time a bit.

Worth noting that the last few years before Unity completely fell apart, there was quite some effort in reducing wait times for various things. So shaders compile times could be measured in miliseconds, and baking was streamlined. These are things I missed when I first switched to Unreal. I think part of it is that we kind of stop noticing the delays as we use Unreal more and more.

[edit] I have since tested startup time with fewer plugins, but got the same result as before. There may be plugins slowing things down, but apparently not amongst the 22 I disabled.

1 Like

I’ve heard the recommendation is 2-3 GB Ram per core, and I can say that CPU matters a lot in general when it comes to speed. Having a high-end CPU helps a lot. It’s not impossible to develop on a lower-end CPU, but the wait times are longer.

Compile time differences are to be expected. C++ compiles to machine code, C# to bytecode. Due to that, the compile time speed differences in Unity’s C# would be more comparable to Unreal’s Blueprints, not C++.

When it comes to materials, if you want to adjust parameters quickly, then the best bet is to use material instances.

1 Like

Me too, switched to UE5 after using Unity for 3.5 years! Enjoying it so far, even when I don’t have a clue what some features do (still)!

Currently staring at my PC whilst waiting for a 1,000 km2 nav mesh to build (about 6hrs total I reckon by time it finishes!), why start small in a new engine!

As for start times (although my UE install is currently on a external HDD) “Cold → Editor Open” is 2m 40secs (i7 11700K CPU) / 96GB RAM, hopefully a few seconds when I get my M.2 drive!