Unreal Engine 4 Bug? GTX 980/970 Lags Placing point of light with Shadows


i was creating a level and placed a Point of light and all the sudden UE4 Becomes laggy and in the game. i’ve asked on Unreal Engine 4 answers / Other people are complaining about it too. (https://answers.unrealengine.com/questions/180648/471-engine-appears-to-causing-a-lot-of-cpu-stalls.html#answer-186139

I’ve found out that turning off the Shadow’s in point of light made it lag free. (i’ve also tried other lights e.g Spotlight etc with shadow on and it’s fine no lag at all.) Seem’s like people using GTX 970/980 is having exact problem.

If Epic Games could Update / fix this would be amazing


Odd, I only got my 970 a few days a go, so really haven’t had much of a chance to use UE4 with it, but decided to give it a go. I noticed no impact in performance in game or editor, even with 20 shadow casting point lights.

No issues here, GTX 980/

Have you updated drivers or anything recently?

we just got a GTX980 at work; quickly tested it with UE4 and a bunch of lights and no problem there either :o driver issue?

Hmm this is strange, My Graphics card has the latest version driver. Not sure the reason why Point of light with Shadow is causing this lag.

I have updated my driver least 2/1 week ago. Strange some people having same problem as me though. D:

It might not be a video card issue, by the looks of it everybody is reporting CPU spikes rather than GPU, and they’re not really that strictly tied to one another.

Does anybody reporting the issue know how to use the Profiler tool? That might let us drill down to where the issue is coming from.

This is a cpu problem. It appears that in some projects Unreal offloads all the GPU calculations to the CPU and that is the reason for these awful performance issues.
Take a look here:Extremely bad performance in a paper2d project that uses streaming levels - World Creation - Epic Developer Community Forums

If you pay close attention to the pictures you can see my CPU usage is out of the roof and my GPU is in idle mode. I hope the Devs will soon figure out what is going on because it is a serious issue and i see that it affects more and more people over time.

How to run this Profiler tool? Also should i add a point of light while using Profiler tool and send the info back on here?