Will replacing Apache with Nginx help?

Question

Nginx

There is a site on Wordpress with Apache, traffic is on average 600 hosts, on VDS RAM 1.5 GB and more often it is completely full, which is why the site slows down, I think to change to Nginx, will it be any use? Can there be crashes after the transition? And what is the best way to do it?
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UPD
Installed Nginx, PHP-FM, PHP7: it helped, and less RAM is consumed, and the server response speed is colossally lower

Answer 1

Yes.
They can if you carelessly configure
Nginx to reverse proxy mode in front of apache

Answer 2

Doctor, something hurts me, I think it's because of uncomfortable shoes ...
If you change the software because you feel that way, you will not achieve anything. What mode are you running php in? What version of everything? How is it configured? Show some output from top and phpinfo.

Answer 3

Well, you see what is packed?
And does
Linux slow down because of this, it always takes all the RAM with the file cache and that's ok