Implementing VDI isn't as simple as looking at a comparison chart and choosing a vendor based on the licensing cost. Factors like hypervisor flexibility and secure remote access technology play a role in the actual price tag for any organization's VDI software.
Citrix and VMware are two prominent vendors in the VDI market, but choosing between them can be difficult when factoring in cost. When comparing Citrix vs. VMware, IT administrators must understand what licensing entails for each vendor and consider every aspect of pricing.
What factors impact VDI costs?
There are underlying aspects of every VDI offering that impact deployment, management, storage, training and licensing costs.
Many features of Citrix and VMware's VDI software are roughly equivalent in functionality, such as the administrative and user interfaces. For example, Citrix StoreFront and VMware Horizon Connection Server similarly process client connections. To determine which is a better fit, admins should focus on the key differences between the two vendors.
While many factors can affect the total cost of ownership (TCO), the main differentiators impacting Citrix and VMware implementations include the following:
- secure remote access
Hypervisors partition large, robust servers into smaller individual virtual servers to provide efficiency. When using a hypervisor, IT must consider its licensing, load balancing, disaster recovery options and more. As a result, the hypervisor's cost and efficiency directly impact the price.
The only hypervisor option with VMware Horizon is VMware ESXi, a VMware vSphere server virtualization suite component. Even when integrated with Nutanix, VMware Horizon deployments still require ESXi as the hypervisor.
Citrix Virtual Apps and Desktops (CVAD) includes Citrix Hypervisor at no extra charge, but IT administrators can deploy CVAD on any hypervisor -- including VMware ESXi, Microsoft Hyper-V and Nutanix AHV.
Before adopting the current Citrix Hypervisor name, the company's hypervisor was called Citrix XenServer. Citrix still supports older versions of the hypervisor that are under this name. However, Citrix XenServer is rarely used outside of DevOps and software testing.
Because admins can select a low-cost or even free hypervisor with CVAD, Citrix has clear cost benefits in this area. For example, if an organization initially deploys CVAD with ESXi as the hypervisor and later determines that Citrix Hypervisor can provide suitable efficiency and lower TCO, CVAD can support this change.
Conversely, organizations that have deployed VMware Horizon must deal with vendor lock-in and use ESXi as the hypervisor. VMware often bundles VMware Horizon and ESXi pricing to provide an enticing licensing package. However, if costs for ESXi licensing increase, it is impossible to migrate an existing Horizon environment to another hypervisor.
Citrix and VMware each offer multiple technologies for provisioning workloads. Each technology depends on golden image replication to create virtual machines. Citrix offers Provisioning Services and Machine Creation Services, whereas VMware provisions workloads through Instant Clones, Full Clones and Linked Clones. Full Clones is not usually ideal for creating workloads due to scalability limitations and storage requirements.
Machine Creation Services and Linked Clones are conceptually similar and comparable from a management and maintenance standpoint. Each technology streamlines the creation of virtual desktops from base images.
Citrix Provisioning Services is a more complex technology, particularly during initial setup, but it is well suited for large environments. Instant Clones represents the more advanced option within VMware's provisioning lineup due to integration with App Volumes and Dynamic Environment Manager.
Workload provisioning is a necessary overhead cost for both Citrix and VMware deployments. The financial impact of management, maintenance and storage depend on which vendor technologies an organization selects.
Secure remote access
Enabling secure remote access to virtualized resources is critical for every organization, so it's a vital factor in the decision of Citrix vs. VMware. Most infrastructure administrators are not also networking administrators, so it is imperative to weigh the cost of secure remote access with the cost of administrative training and overhead.
Admins can deploy CVAD in conjunction with Citrix Gateway; however, some may elect other third-party gateway products such as F5 BIG-IP or Zscaler. Sticking with one vendor and choosing Citrix Gateway may be more efficient -- if a user access incident arises, Citrix support can internally address a potentially two-pronged issue.
Implementing Citrix Gateway for CVAD largely relies on a wizard, but the process isn't necessarily easy. It requires numerous configuration settings, and one mistake could be detrimental. Citrix Gateway also includes the capability to secure VMware Horizon and Microsoft RDP deployments.
VMware Horizon uses the Linux-based Unified Access Gateway (UAG) to provide secure remote access. A wizard interface is also central to UAG, and deployment is straightforward. However, some knowledge of Linux may be necessary for troubleshooting and other complicated actions, potentially increasing administrative costs.
UAG is easier to deploy and manage than Citrix Gateway. However, all secure remote access technologies introduce some complexity for virtualization administrators. Gateways protect enterprise resources and deal with hacking attempts, frequent updates and security scrutiny. When managing a gateway product, one must know about security, certificates, networking, firewalls and vulnerability patching. As such, training and sufficient resources are necessary to ensure proper gateway administration.
Choosing Citrix vs. VMware
From an administrative standpoint, Citrix provides a few more bells and whistles, which also adds to the complexity of managing the environment. Because Citrix is hypervisor-agnostic, avoiding hypervisor lock-in or even using the included hypervisor could result in VDI cost savings. But the administration of VMware is generally more straightforward, especially concerning the secure remote access component.
Deciding which virtualization software is most suitable becomes more complicated when Citrix and VMware -- or their resellers -- offer special deals to bring in customers at a concessionary price. Admins should review these deals with the possible long-term impact in mind. For example, if a VDI package features reduced licensing costs for the first year, what will prevent costs from skyrocketing after the initial period?
Buyers, IT managers and system architects should carefully review the hard costs associated with deploying Citrix or VMware and the feature differences that affect management and maintenance costs. These differences may translate to hidden fees that can adversely impact the long-term TCO.