Like Media Temple's Managed WordPress hosting, Dreamhost has its own Managed WordPress hosting service called DreamPress. Recently, Dreamhost released an updated version, DreamPress 2, which cost only $19.95 per month for one WordPress installation. Compared to the previous DreamPress, the new version is mainly improved in performance.
SSDs equipped. Months ago, Dreamhost's shared hosting has truned to SSDs, now it is DreamPress, with SSDs, files are loaded much faster than regular HDD.
New PHP 5.5 with OpCache. PHP 5.5 with OPCache is simply faster and more compatible with 3rd party WordPress plugins. It's a brand new feautre to DreamPress.
HHVM support. HHVM is Facebook’s faster replacement for PHP. As of WordPress 3.9 and HHVM 2.0, the two work beautifully together. By default, It's not enabled, you are stilling use PHP. HHVM can be enabled in your control panel.
Varnish and Memcached Caching. Varnish sits in front of and is faster than Apache. Varnish improves latency and provides a layer of caching protection for your site during traffic spikes. While Memcached settings which results in faster load times, and fewer requests to the MySQL database. This means you can have more simultaneous visitors on your site.