Epic CEO: Unreal Engine 5 Performance Issues is Mainly Due to Devs Not Optimizing Properly - News
by William D'Angelo , posted on 01 September 2025 / 7,282 Views
Epic Games CEO Tim Sweeney in a media roundtable interview during the latest Unreal Fest event in Seoul, South Korea suggested the reason for the performance issues with some games using Unreal Engine 5 is due to the developer not optimizing properly.
"The primary reason why Unreal Engine 5-based games don’t run smoothly on certain PCs or GPUs is the development process," said Sweeney (via VideoGamesChronicle and Korean website This is Game). "Many developers develop games for high-end hardware, then perform optimization and testing on lower-spec devices in the final stages of development.
"Of course, optimization is by no means an easy task, it’s a very challenging one. Ideally, optimization should be implemented early in development, before full-scale content build begins. We are preparing two major solutions to address this issue.
"One is to strengthen Unreal Engine support. Optimization requires significant manual effort, so we plan to provide automated optimization features for various devices, making the process faster and easier for developers.
"The other is to strengthen developer training. In addition to providing education on the overall testing and optimization process, it’s crucial to raise awareness of the importance of early optimization. If necessary, our engineers can provide direct intervention to raise awareness of optimization techniques and provide technical assistance.
"However, compared to a decade ago, the complexity of games themselves has significantly increased, making optimization at the engine level a challenge. Consequently, game developers and engine developers like us are increasingly required to collaborate to solve these issues.
"We are actively incorporating the optimization technology and expertise we’ve accumulated while servicing Fortnite into Unreal Engine, and are working diligently to ensure the game runs smoothly even on low-spec PCs."
A life-long and avid gamer, William D'Angelo was first introduced to VGChartz in 2007. After years of supporting the site, he was brought on in 2010 as a junior analyst, working his way up to lead analyst in 2012 and taking over the hardware estimates in 2017. He has expanded his involvement in the gaming community by producing content on his own YouTube channel and Twitch channel. You can follow the author on Bluesky.
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Developers have gotten lazy the past decade and almost never optimize their games properly anymore.
However, when its an issue with nearly every game using a specific engine... I start to assume its the engine
I think a lot of it has to do to developers having so much horsepower at their disposal now and with how often we're connected to the internet, optimizing can be viewed as the studios showing their "faith" in the game and offering post launch support. Even in non live service games.
For so long, consoles were incredibly limited in their power, so for decades, studios HAD to optimize the hell out of their games. Now, pretty much all previous limitations are a thing of the past. That's given birth to being more dependent on the consoles raw power, and the increase in dependence of AI tech to handle optimization. Quite the recipe for what we have many times these days.
It depends on the problem. Something like transversal stutter is engine related. Bad general frame rates is an optimisation issue. Developers are throwing features at consoles in a way that is just not practical. Note the best looking/performant games like Horizon Forbidden have have no rautraycing or lumen equivalent features
If I recall correctly, I think a while ago I read that it's actually the developers... but the engine also isn't making it as easy as it probably should. I wish I remembered more details. Anyway, it's probably Epic for providing a poor development experience and developers (probably pressured by publishers) not putting enough effort into optimization. Either one could probably resolve the issue, but neither is doing so (until Epic now).
Shader compilation stutters is down to the engine... And that is ENTIRELY due to the engine's method of compiling shaders in real-time while the game is running.
Any other competent engine/developer will pre-compile that stuff on first boot or install. (No Man's Sky, Horizon etc')
Epic is just trying to pass the blame onto the developers to save face from having negative connotations associated with their engine which may impact sales and revenue.
Money talks and all that.
The devs dont decide whether or not to optimize a game, its the paying guys(publisher) who decide how much money to invest in a game and what part of those money goes to optimization.
The devs are just the hired guys for a job, they work as much as they are payed and in a given time limit.
Creating and relying on scaling technology has made developers lazy. Not bothering with optimisation is just another egg in the basket. Personally, I blame the consumer for normalising it; stop buying the slop and the slop will stop, simples.
For some with no other hobbies, the choice is buy more games or do nothing. Gotta diversify those hobby interest.
There are thousands of great older games to play instead of modern crap
So, every developer on the planet, even ones who used UE4 for years with no issue, just forgot how to optimize all at the same time? Epic should be glad that they have an obvious scapegoat for UE5's performance in the form of RDNA2's mediocre performance in ray-tracing and other effects that it relies on, otherwise they'd probably be looking at an antitrust suit for producing such an utter **** sandwich of an engine when most of the industry relies on it.
UE5 games made by bigger studios like Konami have no excuse not to run properly when a game like Expedition 33 exists.
I think with Delta , there is alot more to render in real time. The open jungle. Silent hill f so far looks and runs great, and that game has less on screen.
Not at all. Delta is segmented into pretty small maps/stages by today’s standards. And there’s nothing really special about the physics or enemy AI. Those are pretty much the same as they were in the original PS2 game.
Expedition 33 renders vastly bigger environments using the same engine, and does so with no performance hiccups.
There has to be something wrong with the way they optimized Delta. Just the fact it has problems running and looking better on the PS5 Pro compared to the regular PS5 is a clear indication something went wrong.
I mean, he's not wrong, but this is the the third straight unreal engine where devs have had years of struggle optimizing.
As someone who has worked in UE4 and dabbled in UE5, I do wonder what areas of optimization devs are skimping on. Cause there's a LOT of ways you can optimize, particularly on the GPU-intensive stuff.
They should all use idtech engine instead
For what it's worth this should be less of a problem once UE5.6 games start releasing. Much better performance.
Agreed. Devs are too lazy and tighter on budgets, no one wants to put in the time to make something look awesome. However look at what Rocksteady and Coalition have done with Unreal in the past. UE5 is more than capable of achieving amazing results.
I think that's fair. There are a bunch of games that we could point that use the engine just fine. Is anybody concerned the next Gears of War is gonna be poorly optimized?
Amén!!
I can't think of any UE5 game that hasn't had issues except maybe hellblade 2
Sounds like something you'd read on here or on twitter, but instead of a console/platform version of it it's a game engine one.
