I have noticed this slowness on all of my WordPress based sites.
But I have a big site with 58 thousand posts. I have been struggling with its speed for a while now.
That wordpress site was converted from another cms system which was working smoothly for 5 years, with the same statistics!
But I had to convert to wordpress to benefit from the endless options and plugins.
Now the real problem is that this site is consuming a huge amount of cpu, which affects all the sites on my server and brings them down every hour or so .. then I would have to keep rebooting... and that causes other problems as well.
So this is what I've done to try and solve the issue:
1- I removed all unnecessary plugins, but Kept the minimum of the ones I need the most.
I had to do that although - ironically - plugins were the reason why I converted to WP in the first place!
Here is the list of plugins I kept and couldn't sacrifice:
Auto Upload Images
Broken Link Checker
Category Checklist Tree
Category Wise Search Widget
Contact Form 7
Intuitive Category Checklist
WordPress File Monitor Plus
Simple Post Views Counter
UpdraftPlus - Backup/Restore
WP No External Links
2- I have used the free Cloudflare service.
3- Have used caching plugins like w3-total-cache (it didn't fix the issue) then used Wp Super Cache and Wp Minify, with no avail also!
The cpu problem continued to occur, although a little bit less frequently than before.
4- Started optimizing the database tables more frequently.
5- I even disabled new registrations, and also disabled all comments of all the site. So the only activity users can do is limited to browsing posts. Thus I have no spam problems.
6- Freed may server space from many gigs; deleted unnecessary files and backups.
All that seemed to be useless in getting rid of the cpu high usage and the bringing of the whole server down every couple of hours.
And this is really frustrating and keeping me from focusing on anything else in my work.
But when I was using other software for that same site, I didn't have such problem, although some of those software was really heavy and complicated ones!
I badly need professional help (I'm willing to pay for it).
I cannot use anything except WP now ... and I seem to be stuck in nowhere.
I use a dedicated server with relatively very good features and capacity, and with a big and respected hosting company.
This is the site:
It gets about 3000 unique visitors and 15000 pageviews daily.
That's it folks
Thanks in advance