Why does Mac OS X behave like this on a MacBook Pro?

Question

macOS

There is a MacBook Pro 2013 13" 4Gb RAM.
When nothing is running, to me, who is used to Linux and iPhone5, it does not seem at all that the speed of work is brilliant, excellent, etc. Rendering imperfections, interruptions, etc. are visible to my naked eye, which before that I've seen Windows for about 5 years. The RAM is almost always (one and a half tabs in chrome running) is almost completely full, at 3.99Gb FPS feels like 24+
At this point I already wanted to start getting upset that I gave an indecent wad of money for a device that, as I thought, should fly with FPS 9000 all the time..
Then I freaked out and decided to test it. I launched:
362 tabs in chrome (three hundred and sixty-two, opened the bookmarks folder)
Recording video from the screen with a standard application
Text
editor Table editor
Calendar
Maps
Safari with three tabs
Video montage in aimuve
Trailer in full hd quality in vlc
The same trailer, but different in the standard player
Installing xcode
and in short all the programs that I had at all
What has changed? Nothing. The laptop began to heat up and make noise. and show all the same "slightly stupid interface" that he showed me without running applications. In chrome, a bunch of videos from YouTube began to speak in parallel, but it was impossible to use chrome normally, but here, I think, even the problem is rather that 360 tabs, a third of which are videos, is too much for my ten-megabit router (if I don’t confuse anything) . Safari worked fine.
The amount of RAM used was over 12Gb, while I have 4Gb installed by default.
Question: why is it the way it works and why does the system not want me to draw an ideal interface when nothing is really running?

Answer 1

Any modern OS tries to occupy all free memory with disk cache, so if you had 64GB, there would still come a moment when the disk cache would eat it all up. And that's okay. You better write down the video, it's easier to assess and understand the cause of the brakes.

Answer 2

one question - what do you not like about drawing the interface? regular software (finder, safari, mailapp, etc.) or a third-party like chrome?
if chrome - then yes, there is such a problem. reason - chromium is the essence of the sediment. they don't give a damn about it. V8 tuning is more important to them than smooth scrolling.
if safari and other regular software - then I don’t even know. except for the animation of the "genie" folding to the dock (enrages, I turn it off immediately) - everything is ok, which is 13 "retina (albeit 8gig), which is 15" retina.
about the familiarity with the good - iPhone 5s - suits. iPad 4 with ios7 - slows down and infuriates.
ps what does the monitor show?

Answer 3

RAM is almost always (one and a half tabs running in chrome) is almost completely full, at 3.99Gb.

1. A clogged RAM is a prefetch, it speeds up the loading of programs.
2. This amount of memory in 2014 will always be clogged. The device is weak. I recommend a minimum of 8GB of memory, depending on your needs.