:::: About Your Hosting
@jrothrock14: With no access to logs or system data, difficult to fix this.
A primary question to ask is the amount of revenue your site will be generating, which will likely determine traffic to site.
If it’s a hobby site or proof of concept site, then traffic will be low + you can run your site anywhere + just ignore speed.
If this site requires handling traffic + will be generating income, likely you’ll require some sort of dedicated server (physical machine), so you can fix things like this.
A HOST-32L machine from OVH is $70 USD + will likely run circles around your current hosting. In the $100 range they also have the HOST-32H + SP-64 with faster cores.
Last year Nov + Dec, I had one of my clients hosted on an EG-32 ($119/month) + this client’s traffic was 100,000+ uniques/hour (your read that right) for 60+ straight days. This server ran at 5-10% usage during this time.
So I’d say, first, change hosting. For $100/month you should have ssh access to all your machine functions.
:::: About Caching
WPRocket (IMHO) is primarily hype. The sites I host (either I build myself or migrate from elsewhere + optimize) easily run 7000+ reqs/sec using WordPress Super Cache. Most of the options of WPRocket should be handled at the Apache level or via other plugins.
As for APC, this is deprecated. You Opcache instead.
Fastcgi is not a caching solution. It’s a way to have long lived PHP instances.
The above site I mentioned (100,000+ uniques/hour) was running straight up Apache + PHP via libapache2-mod-php5 (which embeds PHP into Apache processes).
:::: CDNs + Proxies
Tech like CloudFlare + Varnish + Squid + Nginx + Haproxy, in all my testing, slow down well tuned systems.
If you think about how CDNs really work, you’re better off just using a hosting company like OVH, who’s servers sit right on the global backbone.
Proxies like Varnish + Squid + Nginx + Haproxy, incur additional overhead in every transaction, so will only speed up poorly tuned sites + slow down well tuned sites.
:::: Apache-2.6 + H2 + PHP7 + Future
The next round of code releases is going to have a profound effect on all sites.
The author of mod_h2 (Apache native HTTP/2.0 support) has contributed his code to Apache, so next version of Apache (2.6) will include full native HTTP/2.0 support for SSL that will likely exceed speed of most non-SSL sites, because of how the protocol works.
PHP7 integrates many code optimization strategies developed by Facebook’s HHVM compiler + in most cases outperforms HHVM, in recent tests.
Likely the easiest way you’ll have access to all this new tech is to run a dedicated machine, so you can install these as they release.
I’m working on a step-by-step course right now describing all the tuning I do from kernel through LAMP stack.
http://RealMetalHosting.com has a crude set of notes I’ve been putting together about this recently, if you feel adventurous.
:::: One Last Test You Can Do
Since your site isn’t really online, it’s very difficult for WPT members to assist you.
Put your site online, for additional comments.
And also, as an experiment, switch to Twenty Fifteen + deactivate all plugins + rerun your tests.
Poorly coded themes + plugins (especially related posts plugins) destroy site performance.
Test with Twenty Fifteen + no plugins to get a baseline reference of your site.
Also, remove WPRocket + test with WP Super Cache or ZenCache.
Also, be sure Opcache is installed. Use opc.php (https://gist.github.com/ck-on/4959032) to verify Opcache is tuned correctly.