@leo

Of your 1GB RAM, you’re physically using just over 800MB (Total - Cached), though swap is barely being touched (at least at the time the command was executed).

What that would indicate is that the 5 Ghost blogs are truly using the RAM (or, at the very least, reserving it).

–

There’s a few things you can do that may reduce RAM usage.

Reduce Requests

The first group of assets that I target on the front-end are JS & CSS files. If you’re loading 5-10 JS files and 2-4 CSS files each page load and these files have not been minified / compressed, this can do a number on actual resource usage. This is due to buffers that are required to process there request (i.e. reading the contents of the file). The larger the file(s), the larger the buffer and the larger the resource usage (which affects RAM and CPU).

You should aim for a single CSS file (ideal) and as few JS files as possible. Due to variances in code, not all JS will combine together as a single file and in many cases, the order of JS code is important, so for JS, this is a trial and error process.

Compress each of the JS files using a minifier service, or by using a NodeJS plugin. This should be done once, not on-demand (i.e. compressing and minifying should not be performed on each request); ultimately prior to uploading.

Once you’ve compressed and minified your CSS and JS, make sure it’s cached so that you’re not repeatedly serving it fresh. How you’d go about this really depends on how you’ve setup NGINX.

If you’ll post your NGINX core configuration (nginx.conf) and your server block configuration (yourwebsite.conf), I’ll be more than happy to take a look at it and make some suggestions.

Your core NGINX configuration file should be located at:

/etc/nginx/nginx.conf

.... or your custom location :-).

Use a CDN

Offloading assets to a CDN can lighten the load, speed up delivery and reduce resource usage. MaxCDN is an excellent choice (I use them often), though realistically, any CDN would be better than no CDN :-).

You’d still want to compress and minify your files before serving them, of course.

Optimize Code / Optimize Theme / Reduce Plugins

If you’re able to modify code, HTML etc, optimizing the code and theme would be one of the best places to gain the most benefit. Reducing plugins (if any are installed) is also one way to reduce resource usage. Like WordPress (PHP/MySQL), the more plugins you’re running, the more resources you’ll use as it’s more code to process, more things to do etc.

Upgrade

If you’ve compressed & minified your files and, after we take a look at your NGINX configuration, you’re still not seeing a drop, then upgrading to a 2GB Droplet may be the best overall step – especially if you’re not able to modify code.