Why is UE4 running so slowly?

Why is UE4 running so slowly?
Why does it take 10 seconds to close a window?
Why just modify a node to save the material, and the entire map needs to compile thousands of shader?
Why do we need to wait for more than 10 seconds to delete a file?
UE4 is like a well-equipped grandma.

What are you running it on? I have an old quadcore and things are pretty snappy. If you’re on a lappy with 5400rpm drive, that could be a bottleneck.

yup its all about available performance. you didnt mention your system specs at all. if you try to run the engine on a potato then your gonna have a bad time. my cpu is 4th gen intel i5, 7200rpm HDD and it runs the engine without any issues. also you may want to look at any programs running in the background as that could slow you way down as well. when compiling shaders the engine will use all available resources so every little bit counts. memory is another factor that could be slowing you down, if the system has to constantly retrieve information from the hard drive because there isnt enough ram to store it all then its going to really slow things down.

I am runing on this:

and GTX1080, 256G SSD…
Of course most time it’s runing well,but sometimes the computer is so laggy that annoy me.
What i’m talking about here is the feeling when operating UE4, All I feel is compile and wait. I cant’t just delete a file in UE4 like in windows or unity.It’s not delete,it is d–e–l–e–t–e.
And do u want to change something? ok,compiling.Do u want to update something?ok,compling.And du u want to bring sth new? ok,compling…
But it doesn’t mean that UE4 is not a good engine.On the contrary,it is very good.Excellent visual effect and effective pipeline make this convincing.
I’m just grumbling about the flaws.

I have a similar rig and never thought about the engine performance being inadequate. Observe a performance monitor while you do the things that you do, see which component(s) is being taxed and bottle-necking your system. CPU, drive I/O are the usual culprits.

Perhaps you have some other software that spikes when you perform some of the operations. Anti-virus packages can be dodgy and eat up resources, even Windows services can misbehave.