Correct VDI Sizing

Question

Good day,

Need help in properly sizing a vdi for 45 concurrent users using multi-session aware applications. Workload is light to medium. We initially thought of multiplying the # of users with the memory requirements of the applications but it seems to be excessive given that this is in the cloud.

Any recommendations will be appreciated.

I've checked this page https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/virtual-machine-recs#multi-session-recommendations but it's a little unclear. Do we provision more than one VDI to accommodate 45 users?

Thanks!

Answer 1

With Azure Virtual Desktop you have to choice of going with personal desktops (1 VM per user) or pooled desktops where the VMs are shared by multiple users. There are pros and cons to both options - cost, maintenance, performance etc.

If your user workloads are light to medium then the general recommendation from Microsoft is to assign a maximum of 6 users per vCPU for light users and 4 users per vCPU for medium users. This is just an estimate, it will really depend on your exact requirements. Let's settle on 5 users per vCPU as it's in between the recommendation of light and medium to give us an average.

So for a 4vCPU virtual machine such as the E4ads_v5, that has 4vCPU and you want a maximum of 5 users per vCPU so 4vCPU x 5 users = 20 users per VM of this size. So if you have a total of 45 users connected then you should provision 3 x E4sad_v5 VMs to cater for up to 60 users.

There is no exact science here, you really need to make adjustments until you find the correct fit for your users. I recommend the Eads_v5 VM family in most cases. The E4ads_v5 size comes with 4vCPU and 32GB RAM and I often use this size and choose add more hosts based on the total number of concurrent users.