Ruben Spruijt (Solution Architect and CTO at PQR) and Jeroen van de Kamp (Enterprise Architect and CTO at Login Consultants), a couple of well-known and respected virtualisation experts that lead two separate Citrix and VMware solutions provider, have recently published their none sponsored benchmarks for XenApp performance in a virtual environment.
Their Virtual Reality Check project is a performance analysis of the leading hypervisors (VMware ESX, Citrix XenServer and Microsoft Hyper-V) when running typical Microsoft Terminal Services/Citrix XenApp workloads: a Windows XP virtual desktop loaded with Outlook 2007 and Acrobat Reader 8.
Some of their feedback was as follows:
"Not having the ability to overcommit virtual machine memory is an clear disadvantage when
virtualizing desktops. Such a feature allows much more VM’s to be run than physical memory
normally would allow, which makes a virtual desktop solution much more economical."
"XenServer is clearly optimized for Terminal Server and XenApp workloads, achieving near bare metal performance and even higher user densities than bare-metal configurations. This is possible because 32-bit 2003 terminal server with 4GB memory is relatively very efficient in comparison to other Windows operating systems."
While Microsoft didn’t comment , VMware immediately reacted: the company’s performance team published a new benchmark just few days (Jan 30) after the project Virtual Reality Check was announced (Jan 26).
"The VMware performance study compares XenServer 5.0 and ESX 3.5.0 Update 3 performance when running Citrix XenApp workloads and highlights some odd results compared to what Virtual Reality Check exposed:
ESX supports about 13% more users than XenServer at a given latency while using less CPU."
Simon Crosby, the CTO of Virtualization and Management division at Citrix, provides a possible read:the VMware "study" is not a thorough exploration of a valid set of parameters for the Terminal Services / XenApp workload.
I guess the war is just getting started and it will be interesting to see where this one goes.