# UNREAL ENGINE 5.4 EXTREMELY BAD PERFORMANCE

**URL:** <https://forums.unrealengine.com/t/unreal-engine-5-4-extremely-bad-performance/1821126>\
**Category:** Rendering\
**Tags:** unreal-engine, Performance\
**Created:** [April 25, 2024, 2:56pm UTC](https://forums.unrealengine.com/t/unreal-engine-5-4-extremely-bad-performance/1821126 "2024-04-25T14:56:11Z")\
**Posts on this page:** 1\
**Showing post:** 130

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**Author:** ![Krabworks](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/krabworks/32/1194549_2.png) [@Krabworks](https://forums.unrealengine.com/u/Krabworks)\
**Post date:** [March 3, 2025, 1:45pm UTC](https://forums.unrealengine.com/t/unreal-engine-5-4-extremely-bad-performance/1821126/130 "2025-03-03T13:45:46Z")

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Thanks so much 😃 I had reported the same issue here also before realizing others were having the same problems:

> [@RHIT and Game Thread Running Sequentially (UE5.3.2) only in Shipping Build](https://forums.unrealengine.com/t/rhit-and-game-thread-running-sequentially-ue5-3-2-only-in-shipping-build/2369287):
>
> Hi Yall - I’ve seen a couple of threads on this ([Desync between the Render and Game Threads?](https://forums.unrealengine.com/t/desync-between-the-render-and-game-threads/2151039)) but still no comment on why it happens or how to fix it. Basically the RHIT and Game Thread run simultaneously in editor, but as soon as the game is packaged, RHIT waits for game thread completion before starting. The result is massive performance drop (13ms frame time to 17.5ms!). In editor, we see this: You can see here that RHIT and Game Thread are running simultaneously. But as soon as…

And for me, even as far back as 5.3.2 RHIT runs parallel to Game Thread in-editor:

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/8/6/88620d91bbcacada8db42ba5f5d55001e6ababa2.png)

But in the packaged game (both shipping and development) they run sequentially, meaning that packaged projects run about 30% slower than projects in-editor simply because RHIT won’t run in parallel:

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/6/7/66797ddf7001c541a5458fc6a4071c50aa571d56.png)

You can see the frame time is about 4ms worse in packaged projects because of this issue.

Parallelization was listed on the roadmap for the 5.4 Release, so I’m not sure why it works in-editor in the older engine version 5.3.2 and then not at all in packaged projects or in the later 5.4 and 5.5 releases even though this was a major selling point of those updates.

It’s also worse on some hardware than others. I have an RTX 4080 PC that suffers badly from this. On the RTX 3080 with Outdated NVIDIA Drivers installed, it doesn’t happen at all.

In theory, the 4080 should be a much faster card but the older 3080 system outperforms it significantly (90FPS on the 3080 system vs. 55 on the 4080) because of time spent waiting for RHIT to run in sequence (the above screenshots are from the 4080 system). Both PCs have Intel 12900 CPUs running on the same version of Windows 10.

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