cPanel comes as two variants. One for dedicated servers and one for VPS servers. The dedicated server’s version is called standard and the VPS variant is called the VPS optimized. As the name says, the one for the VPS servers are lot compressed to run in a tighter resource allocation and hence it is cheaper. Better performance is delivered by the standard version, though. Lets see how they varies in detail.
As the name indicated it is the standard version of cPanel. It is designed to use full hard ware cpabilities of the server. The standard version is designed to be installed on a full dedicated server, which allocates 100% of it’s hardware to the operations of that machine. You can install Standard version of cPanel in these OS-es :- CentOS versions 4.x, 5.x, 6.x , Red Hat® Enterprise Linux® versions 4.x, 5.x, 6.x , CloudLinux 5.x .
Previously cPanel did work in FreeBSD, nut lately they are discontinuing the support for the OS because of the standardisation that they are bringing into the software.
VPS Optimized is a version of cPanel available for use to customers whom purchase a VPS license. VPS Optimized, will deliver the same features and functionality as cPanel. VPS Optimized allows you to run cPanel smoothly within the memory constraints of a VPS. VPS’s usually have RAM contraints. VPS Optimized is designed to be installed in a virtual environment. It maintains the same functionality as cPanel but has simply been optimized to easily and successfully operate within the constraints of a VPS environment.
VPS Optimized have a 12-15 Megabyte reduction in standing memory usage. Add that to the nearly 60% memory usage reduction from previous versions. This is accomplished while retaining all functionality of a regular cPanel/WHM installation. Additional improvements include a redesigned log processing daemon that reduces memory utilization, and a process monitoring daemon that includes service-specific verification. The third layer of performance enhancing features focuses on DNS clustering with the syncing process and error detection.
You can run VPS optimized in these environments :-
KVM, Linux-VServer , Microsoft Server® 2008 Hyper-V , Stable versions of OpenVZ , Oracle VM VirtualBox, VirtualBox OSE, Virtuozzo™, VMware® Server, VMware® ESX Server , Xen, XenEnterprise™, XenExpress™, XenServer™