We use dedicated servers from Nexcess for most of our supported websites. A single dedicated server can be used for dozens of websites depending on the amount of activity.
Some clients have a dedicated system just for their use while others are installed on one of our dedicated servers.
Management of the dedicated server is done through the Nodeworx control panel. From there you are able to go directly to PhpMyAdmin, edit Cronjobs for any account, as well as create individual sub accounts for hosting one or more websites.
Management of a sub account is done via the Siteworx control panel. A Siteworx account can host multiple websites with different domains. In the control panel you can create new website domains, manage MySQL databases and users, and everything else one normally associates with website hosting management.
Each Siteworx account runs it's own dedicated PHP server. This allows you to run a different version of PHP for each different Siteworx account. Nexcess will quickly install any PHP extensions you require for a Siteworx account - as well as making specific PHP configuration changes, as well as many other configuration changes that apply to a specific web hosting account.
An extremely huge benefit of using a dedicated server is that we can also have system wide configuration changes made on the system - including upgrading and installing additional software packages. For example, on dedicated systems we always have Git upgraded from the default version[1.7] to the latest version.
Additionally, Nexcess includes free access to extremely useful third party services for customers using dedicated servers. This includes a CDN service and advanced system and site performance monitoring via New Relic. Thanks to the system performance monitoring through New Relic - it is easy to review performance and determine when to upgrade from a SIP 400 to a SIP 500 or even to a Clustered System managed by Nexcess.
Depending on the performance needs for a website, we have 2 configurations we use for clients.
A single siteworx account which is used to manage the Production, Staging, and Development websites. Using a single siteworx account provides for ease of deployment and fast comparisons between the testing sites and the production site.
Two siteworx accounts, one for the Production website and one for Staging, Development and other testing websites. Using two siteworx accounts allows us to increase the resources assigned to the production website and minimize the resources assigned for the testing websites. Deployment and code comparisons become slightly more complex as now they require using ssh to connect from the testing siteworx system to the production siteworx system.