When utilizing Azure Virtual Desktop (AVD), there are several strategies that IT teams can implement to keep computing costs down while improving the management experience. One of the most popular tactics is to leverage session-based virtual desktops to maximize resources.
However, IT teams must understand the differences between session-based and personal desktops and the optimal circumstances for both when architecting their host pools and virtual machine (VM) resources.
Differences between Personal and Session-based Desktops
When trying to determine which type of desktop best fits your users’ needs at scale, it’s important to start by ensuring you know the difference between the two.
- Personal Virtual Desktop – Where a single VM is used for a single user to run their desktop. This is almost identical to traditional endpoint computing in which every user had their own physical device with its own operating system (OS), memory, etc. In terms of what types of VMs are best for this type of desktop, we typically see personal desktops using the D series (standard CPU to Memory ratio) with D2 being most common for average workers and D4 for heavier, non-GPU, users.
- Session-based Virtual Desktop – Where multiple users share the resources of single VM. Each user has their own personalized virtual desktop experience with their own unique profile including favorites, shortcuts, apps, etc. But they share the same OS, CPU & RAM of a single VM.
How Azure Virtual Desktop Fits In
Azure Virtual Desktop, introduced to the market in 2019 as Windows Virtual Desktop, brought with it big changes to multi-session computing because it allowed for truly native Windows 10/11 desktops that could be personal or session-based. In the past, the only way possible for session-based desktops was to use a server OS (Ex. Windows Server 2016/2019/2022) with desktop experience (hello RDS). But this unfortunately introduced application compatibility issues when trying to run desktop-based apps on a server OS.
AVD also introduced webcam/microphone optimizations for Teams, Zoom and multimedia redirection not found anywhere else. For example, you can play an 8K video on YouTube and not degrade your neighbor’s desktop experience. I dare you to try that with RDS!
AVD is such a game-changer because Azure is the only way to run Windows 10/11 multi-session desktops, keeping costs low and the user experience high. This is a distinct competitive advantage for Microsoft and its partners.
Advantages of Multi-Session-based Desktops
The two biggest advantages of session-based desktops are cost reduction and easier management of your virtual desktop environment.
When looking at a personal desktop, or 1:1 VM ratio, resource utilization typically is only at 20% – 50% on average. This means 50% or more of the resources (RAM & CPU) are not being used, yet someone is incurring the full cost of these unused resources. Multi-session puts anywhere from 2-7 users on a VM so that average resource utilization is closer 80%.
This is on purpose so that users still have resources to “burst” during times of abnormally high resource utilization across a company’s workforce. Overall, teams can still ensure they have the capacity to serve employees during peak usage periods while saving a lot of money that would otherwise be wasted.
Simply put – multi-session reduces the amount of VMs a team must manage. In a 30-user environment would you rather manage 30 VMs or one in a cost-efficient manner? If we run 30 users on one VM we have to monitor, re-image, license and patch one VM. If using dedicated, personal desktops we’d have to do all of this 30 times.
Specific Use Cases for Personal Desktops, Dedicated VMs
While session-based desktops can greatly optimize and streamline an AVD environment, in our experience there are certain use cases when a personal desktop is the best option.
Local Admin Access
If a user needs to be able to install their own apps or needs more granular access to make changes to their desktop, assign them a personal desktop. If this type of user were on a session-based desktop leveraging multi-session to share resources with others, the user’s changes will now impact everyone else sharing that VM.
We often see this being the owners of SMB clients our partners serve. For example, a partner at a law firm doesn’t want to open ticket and contact their MSP every time they want to download a new app. Another common type of user we see assigning personal desktops are developers as they have constant needs for installing and uninstalling apps.
Use dedicated desktops for the type of end user that no matter how much CPU, RAM you give them, they’ll consume it all. They are streaming videos, webinars, and operating with a ton of tabs open on their browser. To the example in our first point, if this person were to be on a session-based desktop, they’re stealing resources for everyone else sharing that VM.
This use case is not super common, but one we see from time-to-time. Certain apps won’t work in multi-session environments. Certain apps (ex. AlphaCam) won’t work in multi-session environments because of the way they’re written. So, a personal desktop is the only option.