The “Unreal Engine Launcher” is sitting idle at 12%-15% CPU, all the time, even in the background.
Then when I launch the editor, UE4Editor sits at 60%-70% on the welcome screen (the one that says “Projects” / “New Project” / “Marketplace”). I don’t have any project or anything loaded yet. I’m not doing anything.
I have a 2014 MacBookPro Retina 13 inches (core i5, 8GB RAM, Intel Iris card). I know it’s a bit low on spec, but it seems crazy that it’s using so much CPU to do nothing.
Thanks for reporting this. We’re working on a fix.
It seems that this varies from Mac to Mac (depending on your graphics card), but yeah, on some it’s really serious 
Hiding the Launcher (or closing it) helps, fortunately, so while hardly a perfect workaround, I hope you can live with that until we have a proper fix.
Thanks . Closing the launcher helps, but the editor still uses ~60% CPU. I’ve found that limiting the frame rate (t.MaxFPS 15) also helps and brings the CPU usage down to ~50% or so. Unfortunately, this constant high CPU means the editor isn’t really usable for practical purposes.
Yeah, the way we currently handle UI when there’s not much going on needs a fix. We simply refresh it way too often. Sorry about that. For what it’s worth, once you open any project, the viewport rendering is using most of the computer’s power, the editor’s UI is taking relatively small percentage of CPU and GPU.
A question, if I may, so I can compare with a few Macs I have access to. Does the 50-60% CPU usage you mention mean 50-60% of a single core is used, or 50-60% of the whole CPU? In case of my MacBook Pro it’s the former, so the whole CPU is 90% idle (see screenshot), but maybe in your case it’s the latter?
Right it’s 50%-60% of a single core. Activity Monitor on my machine looks pretty much identical to your screenshot
OK, thanks for update. Glad it’s not as bad as I initially thought. Doesn’t change a fact it needs improvement, of course. We’ll keep you posted.
just a note that Unreal Engine only takes 8.8-10% of one core on my Mac Pro 2013 8-core
Good to know, thanks. If anyone’s interested, the screenshot from Activity Monitor I posted was taken on MacBook Pro 15", Late 2013, 2.3 GHz i7, 16 GB RAM, GeForce GT 750M.
Same exact machine I have, and our usage is pretty much identical. Just to give you another data point 
i also have the exact same macbok pro 15 late 2013 Retina but mine is also laggy in editor mode. but when i run in game mode it is good enough. I dunno if this is something that is going to be enhanced later or that is the hardware requirement which is far greater…
As far as I know 750M is much faster than 6770M. Did you try the patch and suggestions (hiding the Launcher, changing scalability settings) from here: UE4 Perf Woes - iMac - Platform & Builds - Unreal Engine Forums?
Seriously? You are using a 750M ? Then my Screen card is actually better, isn’t it? I am using an AMD Radeon HD 6770M on my 2.7 Core i5 with 12 GB ram.
MY system uses 7% While the editor is open and I get Framerates of between 0.5 and 7. I have come to the conclusion that the only way I am going to be able to use the UE is if I buy a new computer with a better graphics card seeing as how I match and exceed the specs you provided except for the screen card so the problem MUST be that my screen card is too slow.
But if you are using this on a 750… isn’t the 6770 more powerful?
I went as far as turning off all lights and anything else I could think of. I closed off all panels and even scaled the viewport down to 25% of my display and that way I get frame rates of 22FPS while I am standing still and 0 to 3 FPS while I move the camera.
Of course, I am using the binary cause the source won’t build and I can’t get a reply from anyone except for “post your question in another place” so I can’t try that t.MaxFPS setting tip so I am stuck… Either I spend a $1000 on a new computer or I can’t use UE
Are you telling me there is another option?
Please give me some insight into that! 
Right now, using only 7% of my system and getting an average of 3 FPS really doesn’t do anything for me…
Please note that when I took this screen shot I had other stuff open also like mail and iTunes and obviously Safari to name but a few but normally when I run the editor I have everything else closed and still get the same results.
This is not just a MAC problem. This problem also exist on Windows 7 PC, 24% CPU load with only the launcher running, you don’t even need to start the editor for this high load to occur.
well yeah i got this laptop due to its hardware before using UE4 and the reason was Autodesk Maya and Game Dev but now i am confused actually if this is actually hardware or software issue cuz yes you are right 750M is much faster as it is supposed to be…
I am downloading the patch right now to see what that does. Thanks.
I just hope it’s not source cause the editor doesn’t work after a source build… Touch wood this patch does something for me.
As for the scalability, yes, i set that to the various settings and at low I can actually use the editor at a decent speed (and actually even PLAY the level! 0,o ) but as soon as I change the textures up one level, forget about it…
As for the cards… Hmmm… As an iMac user I don’t really follow upgrades so my knowledge of screen cards is limited to the little bit of info my mate gave me recently. Basically, when the screen card’s name has 3 digits: the first one is the series and not really all that important, the second is the range of the card from low end crappy(0) to high end praise worthy (9) with 5 being a “meh” card, a “7” being a mid range and a 9 being kick ■■■!
When the name has 4 digits then the first is still the series, the second or the third I forget what it means but the other one is the range as explained above.
So by my understanding the 750 is a graphics card made for stuff like word processing and watching videos while the 7660 is made for design work like Maya and Unity etc while still not top of the range.
Maybe my reasoning is flawed but that is how I understood it. Are you saying I have it wrong and the 750 Is actually more powerful? I hope you are wrong cause if you ar then I might have to buy a new computer
and , I have the same exact machine as you guys () and my Activity Monitor displays the same exact numbers, hope this info helps!
Same thing on Windows 8.1
