Using SG Optimizer with WP Rocket

Yes! WP Rocket is compatible with all 3 levels of SiteGround’s caching:

Static Cache
Dynamic Cache (NGINX)
Memcached

And it is also fine to use their SG Optimizer plugin at the same time as WP Rocket.

Caching will be active in both plugins. WP Rocket provides file-based page caching, SG Optimizer provides caching through NGINX. In cases where the request is not served from the NGINX cache, it will be served by WP Rocket if available.

When you purge the WP Rocket cache it also purges your SiteGround cache, and vice versa.

I'm getting a MISS from Siteground's cache

Note that the first request to a page will be a MISS if it hasn't been cached yet. Subsequent requests should be a HIT.

There are a couple of cases where you may consistently be getting a MISS from Siteground's cache. The page is still cached by WP Rocket. However, you can resolve the MISS in either of the following ways.

Disable the following WP Rocket options:

Separate cache files for mobile devices (This is not required on most sites that have responsive themes)
User cache

~ OR ~

Disable WP Rocket's page caching

NOTE: If the above doesn't work for you, you can try following the steps in this article: X-Cache MISS when WP Rocket is activated

Duplicate features in SG Optimizer

Since SG Optimizer v5, they have added some additional features which duplicate some of WP Rocket's. It's still fine to use both plugins, but duplicate features should be avoided.

The following features overlap and are activated automatically by WP Rocket. So these should be deactivated in SG Optimizer:

Web Fonts Optimization
Optimize Loading of Google Fonts

The following features overlap and you should have them active in only one of the plugins.

Minify JavaScript files
Minify CSS files
Defer Render-blocking JS
Combine JavaScript files
Combine CSS files
Lazy Load Media
Disable emojis
WordPress Heartbeat Optimization
DNS Pre-fetch for External Domains
Scheduled Database Maintenance

The following are some of the features provided by WP Rocket, that are not included in SG Optimizer:

Separate cache for mobile devices
Logged-in user cache
Cache Lifespan Expiration
Delay JavaScript Execution
Optimize CSS delivery (Load CSS Asynchronously and Remove Unused CSS)
Replace YouTube iframe with preview image
Cache Preloading
CDN integration
Add-ons: Sucuri
We have also automatic compatibilities with various themes and plugins.