Comparing VMware Horizon vs. Azure Virtual Desktop

What is Omnissa Horizon, formerly VMware Horizon?

In November 2023 Broadcom completed the acquisition of VMware and made the decision to sell the end-user computing division. That led to investment company KKR purchasing and reintroducing this division under a new name: Omnissa.

There are now two products available: Omnissa Horizon 8 and Omnissa Horizon Cloud Service. Omnissa Horizon 8 is the VDI product that allows organizations to deploy an on-premises environment. With the Horizon Cloud Service, the management components for the virtual desktop environment are always cloud based and customers can choose to run desktop workloads on premises or in the cloud. These two offerings allow organizations to choose between an on-premises, cloud or hybrid model.

What is Azure Virtual Desktop?

Microsoft Azure Virtual Desktop (AVD) was introduced in 2019 as Windows Virtual Desktop, as a true cloud-based desktop-as-a-service technology. In February 2024, Microsoft also made virtual desktops available in combination with Azure Stack HCI, allowing organizations to run virtual machines on premises as well as in the cloud.

Comparing Azure Virtual Desktop vs. Omnissa Horizon

Organizations that want to run a virtual desktop environment should compare these two technologies to understand which is the best fit for their users and IT staff.

On-premises vs. cloud

For end users, it doesn't matter where their desktop runs. In fact, users don't care if they use a physical desktop or a virtual desktop as long as they can do their job. For the organization, it does matter where desktops run. And that is not only true for desktop virtual machines, but also for machines running server workloads.

There may be regulatory reasons why some workloads and their data must remain in a privately owned data center, but these aren't the only reasons. Organizations may want to run workloads on an on-premises deployment such as full control over version management and availability options. Some organizations may not be comfortable being dependent on the availability of a cloud provider's environment as well. Both vendors offer a cloud-based and an on-premises solution but there is a huge technical difference because they both rely on a different hypervisor.

Omnissa Horizon 8 runs on VMware vSphere -- a mature hypervisor that also comes with options for vSAN storage -- and integrates with VMware NSX for security. The integration with the hypervisor has always been a strong point for Horizon. The deployment time and resource savings with the Instant Clone technology are unparalleled by any other hypervisor on the market. For customers that already run vSphere, adding Horizon is a logical step. An uncertain factor after the separation from VMware is what will happen with future integration with the hypervisor and the vSphere licensing. But at the moment, the two are tightly integrated, and for recent deployments and new deployments, the stack will remain supported.

Microsoft also offers an on-premises deployment option with Azure Stack hyperconverged infrastructure (HCI). This was already available to run Azure workloads on hardware hosted in a customer's data center since 2022. In 2024 it also became available as a platform for AVD. Customers can choose hardware platforms from several major vendors. Dell Apex Cloud Platform for Microsoft Azure is the first technology for Azure Stack HCI available with version 23H2 -- soon to be followed by HPE ProLiant, Lenovo ThinkAgile and DataON. For administrators already managing an Azure environment, it will not require too much effort to learn how to manage the on-premises environment.

Supported virtual desktop OSes

Microsoft supports Windows 10 and 11 Enterprise -- including multi-session -- and Windows Server editions 2016, 2019 and 2022 to deploy session hosts. Omnissa supports a broader range of Windows 10 and 11 editions with Enterprise but also Pro and Education. Windows Server 2016, 2019 and 2022 can function as desktops with Horizon. Horizon also supports the use of Linux as a virtual desktop. Horizon supports a few major distributions from Ubuntu, Red Hat Enterprise and SUSE Linux Enterprise Server.

It might sound strange for a virtual desktop product, but Omnissa Horizon 8 supports access to physical computers. IT can install the Horizon Desktop Agent on a physical system to allow a user to access that computer remotely. AVD and Horizon Cloud do not support such functionality.

Azure Virtual Desktop stands out for its ability to use Windows Enterprise multi-session. This is similar to Windows Server as a session host, but with a Windows Enterprise desktop license and a familiar Windows desktop experience for end users.

Client support

Both AVD and Omnissa Horizon support thin clients. The same major vendors, such as 10ZiG, Igel, Dell, HP and Stratodesk, support both. They also both support the major platforms to install their client such as Windows, macOS and mobile devices. One difference is Linux, for which Omnissa has a client and Microsoft does not.

Display protocols

Microsoft AVD uses the Remote Display Protocol (RDP), which has been the protocol of choice for Windows environments for many years. Omnissa uses the Blast Extreme protocol, but when necessary it can fall back to using RDP.

RDP was not always the fastest protocol, but Microsoft has implemented several improvements on this front. Within AVD, Microsoft extended it with advanced features such as RemoteFX for efficient lossy image encoding. Compared to Omnissa Blast Extreme, RDP -- formerly VMware's protocol -- now also connects via TCP and UDP and since 2023 supports RDP Shortpath. This feature allows clients to set up a direct connection with the session host, bypassing any relay points, and with that in place, IT can improve round-trip time and UX. This was already possible with Blast Extreme. Both protocols also support their ability to adapt to network characteristics. VMware was already doing this with the PCoIP protocol and has built that into Blast Extreme from the beginning. Microsoft has now added this functionality to RDP. The protocols continuously monitor network bandwidth and latency, and can adjust image quality, used codecs and compression to optimize UX.

Both vendors support the use of hardware GPUs to support high-end graphics processing.

Device redirection and other redirection types

Users connect devices to their computers and therefore those devices must also connect to their virtual desktops. Common devices for redirection are USB devices such as hard disks and flash drives. Both vendors support this feature, but Microsoft only supports this from Windows computers. Omnissa Horizon supports USB redirection from all its clients and even from HTML-based sessions if a driver for that purpose has been installed on the client computer.

Other redirection features such as the clipboard, local disk, printers, scanners and smart cards are all very similar for both vendors. Customers with specific needs for redirection would best check the vendor's documentation to verify what is supported. Microsoft's support is straightforward, but Omnissa's Horizon and Horizon Cloud Service have documentation spread out over numerous pages so its documentation hub is a good place to start.

Profile and application management

For Windows desktops, some form of application and profile management is a necessity to manage the environment and keep users happy. They will want to keep their settings across sessions and to work with their required applications. Both vendors support this in one form or another.

Microsoft AVD uses FSLogix profile containers to store user profiles. This works in a similar way as with regular virtual or physical desktops. Omnissa offers Dynamic Environment Manager, a product that it acquired many years ago, which allows admins to set up default settings for OSes and applications while storing user settings across sessions.

For application delivery, the first option is to install them in the golden image to make them available to all users. It might, however, be simpler to maintain the ever-changing applications landscape when they can be delivered dynamically. Both vendors offer a product that can attach applications to desktops. Microsoft AVD offers App Attach, which can deliver MSIX packages to desktops. Omnissa offers App Volumes, which can attach application packages to desktops. They both require admins to build an application package before they can assign them to user desktops.

Users can access virtual desktops and then run their applications inside a full Windows desktop session. This is the most practical option when accessing the session from a desktop or laptop and when using multiple applications. But from a mobile device, accessing a virtual desktop and then navigating through a Windows application is often difficult. The second method for application delivery that both vendors support is a feature to stream a single application from a session host to a client. A user that accesses such an application gets seamless access to that application as if it was running locally. For AVD, this is called RemoteApp and with Omnissa it's called Published Apps.

Subscriptions and pricing

There are no longer perpetual licenses for the Omnissa Horizon offerings now that it is an independent business. It has followed Broadcom in the decision to only offer this software via subscriptions. That creates a level playing field for the two listed vendors. There are, however, differences in how they offer their subscriptions.

It's not possible to offer a pricing comparison because there are too many factors that go into total cost of ownership. Microsoft offers more options with a pay-as-you-go plan, a savings plan with a fixed minimum amount at a discounted price, and a reservation with a one-year or three-year fixed fee for a reservation of a specific instance. For Omnissa both the on-premises and online offerings are available with a monthly subscription.

How to choose between AVD and Omnissa

There are many similarities between the two vendors when it comes to how desktops can be offered, both on-premises or cloud-based. With both platforms, organizations can offer virtual desktops to users with profile management and application delivery. And both vendors allow customers to calculate upfront what the costs will be for their subscription. From a technical perspective, there is no one feature that stands out to have a huge effect in deciding between these vendors.

In the end, each organization's choice will most likely be made based on the software and infrastructure they already have and what the administrators already have experience with.

One feature that might be of interest to certain customers is Omnissa's support for Linux for both desktops and clients. For customers in fields such as academics, where Linux is commonly used for research, this product feature might be a tiebreaker when deciding between these technologies. Omnissa has overall broader support for other platforms than Windows, such as certain features on macOS clients. Omnissa will be more open to future development on platforms other than Windows than Microsoft is.

While the Omnissa brand name is new, it is a continuation of the VMware products that have matured over the past two decades. Azure Virtual Desktop is relatively new as its own technology, and it runs on a cloud system hosted by Microsoft that is now well established in enterprise markets.

In the end, each organization's choice will most likely be made based on the software and infrastructure they already have and what the administrators already have experience with. Those customers already running a Windows hypervisor environment, where administrators have experience with Windows management and maybe even Azure management, would be most comfortable with an Azure Virtual Desktop deployment. It's worth mentioning that organizations can deploy Omnissa Horizon Cloud in Azure Cloud, so that would still be an option for those customers.

For customers seeking an on-premises deployment, Omnissa Horizon is probably the best choice, especially for customers already running the vSphere hypervisor. VMware developed Horizon as an on-premises product from the beginning -- and therefore the software stack -- but also design guidelines to integrate perfectly with existing on-premises infrastructure.

Rob Bastiaansen is an independent trainer and consultant based in the Netherlands specializing in VMware and Linux. He writes articles for several print and online publications, and is founder of VMwarebits.com, a site dedicated to technical content related to VMware.