Select everything and “h” to hide everything. Then change to rendered view. The shader compilation takes a second compared to have everything visible. Then “Alt+h” to show everything again.
I don’t know why it’s so slow to compile if everything is visible but at least it works for me by doing this this way.
good to know for all eevee users.
there also exists [in the preferences window, system tab] one setting called “max shader compilation subprocessses” for the parallelisation of the process, using more [or even all] of the possible processor threads, perhaps worth to check this setting too.
happy 
ing!
Well, I’m not sure if that really makes a difference…
Of course if there are no shader/materials to compile the execution time is pretty fast. But as soon as you alt-h there are material to display and they need to be compiled.
Keep in mind that there is a cache , so if a shader is compiled once and you reload the scene it’s going to be faster unless it’s no more in the cache.
Maybe try with a scene you didn’t open for a long time, with many materials…
I did. The result is consistent that hiding is faster however I’m on a really old gtx 970 so that might be a factor. One way to be sure is that someone else test what I did and compare times?
I tried, however I didn’t measure time, as it would requires to make sure the cache is erased and I don’t know where it is on linux 
Once I alt-h blender started to get sluggish as usual until every materials are displayed correctly !
Linux is cheating
I’m on windows 10 so it can be any factor why it behaves like it does.
