By David, , updated
For most pooled Azure Virtual Desktop desktops, the best VM size is an 8 vCPU general-purpose D-series VM, such as D8as_v5, D8s_v5 or their v6 equivalents, with 32 GB of RAM. Choose memory-optimized E-series only when monitoring shows memory running out before CPU, and avoid burstable B-series for multi-session hosts, because they're throttled to a fraction of their CPU once their credits run out.
The short version: D-series (4 GB per vCPU) fits Office, Teams, browsers and line-of-business apps. E-series (8 GB per vCPU) costs about 31% more an hour and pays off only when memory caps your sessions per host below about 15 on an 8 vCPU host. B-series suits a lightly used personal desktop or a test pool, not a busy multi-session host. Pick 8 vCPU as the default size and let pilot data move you.
Microsoft figures reflect Microsoft Learn as of November 2026, with links at the end. VM prices are the approximate pay-as-you-go rates our AVD cost calculator uses; check the Azure pricing page for your region.
This post expands the VM family step of our Azure Virtual Desktop sizing guide. For how many users each size holds, see AVD users per vCPU.
D vs E vs B series at a glance
| Series | Example size | vCPU / RAM | Approx. price per hour | Best for | Avoid when |
|---|---|---|---|---|---|
| D-series (Dasv5, Dsv5, Dasv6, Dsv6) | D8as_v5 | 8 / 32 GB | $0.384 | Most pooled desktops: Office, Teams, browsers, line-of-business apps | Memory runs out while CPU is still free |
| D-series with local disk (Ddsv5) | D8ds_v5 | 8 / 32 GB | $0.452 | Hosts that put temp files or the page file on the local temp disk | You don't use the temp disk: you'd pay about 18% more for nothing |
| E-series (Easv5, Esv5, Esv6) | E8as_v5 | 8 / 64 GB | $0.504 | Memory-bound users: many browser tabs, large Excel models, Java or Electron apps | CPU, not memory, is the limit |
| B-series (Bv1, Bsv2) | B8ms | 8 / 32 GB | $0.333 | Lightly used personal desktops, test and pilot pools, jump boxes | Busy multi-session hosts that run all day |
| F-series (Fsv2) | F8s_v2 | 8 / 16 GB | Not in our calculator | CPU-heavy, light-memory task work | Users run Teams and a modern browser |
Microsoft's own sizing examples for light, medium and heavy multi-session workloads are all D-series and F-series sizes (D8s_v5, D8as_v4, F8s_v2, D16s_v5 and similar). In practice D-series has replaced F-series for most desktops, because 2 GB per vCPU is tight once Teams and a browser are running.
D-series: the default for pooled desktops
D-series gives 4 GB of RAM per vCPU. On a D8as_v5 with 20 sessions that's about 1.6 GB per user before the operating system and agents take their share, which is enough for typical Microsoft 365 users and leaves CPU and memory running out at roughly the same time. That balance is why it's the default.
A few things about D-series names:
- The letters after the size number matter. In D8as_v5, the "a" means an AMD processor and the "s" means it supports Premium SSD. D8s_v5 is the Intel equivalent at the same price in our calculator. A "d" (D8ds_v5) adds a local temporary disk, and an "l" means less memory per vCPU.
- Newer generations have different requirements. v6 and v7 sizes need Generation 2 VMs with Trusted Launch and an NVMe disk controller, so they aren't a drop-in resize from v5. How to convert Azure VMs to v7 sizes covers the checks and the in-place conversion.
- Older generations are on a retirement path. Microsoft has announced retirement of the Dv3 and Dsv3 series, planned for 15 November 2029. New pools should start on v5 or later.
E-series: when memory is the bottleneck
E-series doubles the memory to 8 GB per vCPU for about 31% more per hour (E8as_v5 at $0.504 against D8as_v5 at $0.384). It's the right call when a host pages heavily while CPU still has room: users with dozens of browser tabs, analysts with large spreadsheets, or apps built on Java or Electron.
The way to decide is cost per user, not cost per VM. If memory forces you to cut a D8as_v5 host to fewer sessions, the bigger E-series host can be the cheaper option:
| Host | Sessions per host | Price per hour | Cost per user-hour |
|---|---|---|---|
| D8as_v5 | 20 | $0.384 | $0.0192 |
| D8as_v5, memory-limited | 14 | $0.384 | $0.0274 |
| E8as_v5 | 20 | $0.504 | $0.0252 |
The break-even is about 15 users: if memory limits a D8as_v5 to fewer than that, an E8as_v5 running 20 sessions costs less per user. Above it, stay on D-series. Before you switch, check that a browser isn't the cause: optimizing Microsoft Edge on multi-session hosts covers the policies that cut its memory footprint.
B-series: why burstable VMs don't suit multi-session hosts
B-series VMs are cheaper because they don't give you their full CPU all the time. They earn CPU credits while running below a baseline and spend them to run above it. When the credits are gone, the VM is throttled to its baseline until it earns more (B-series CPU credit model).
The baselines are low. A B8ms has a baseline of 17% of its CPU, and a B8s_v2 has 40%. A multi-session host serving a pool through the working day sits well above that from the morning logon wave onwards, so it spends its credits early and spends the afternoon throttled, which users feel as lag that gets worse as the day goes on.
B-series does make sense for:
- Personal desktops for light, occasional users, where the VM is idle most of the time and bursts briefly.
- Test, pilot and image-build pools, where cost matters more than steady performance.
- Jump boxes and admin hosts that sit idle between tasks.
The original B-series (Bv1) also has an announced retirement, planned for 15 November 2028, with Bsv2 as its successor.
How big within the family: 4, 8 or 16 vCPU
Once you've picked the family, pick the size. Microsoft recommends multi-session hosts between 4 and 24 vCPUs, and never above 32. The price per vCPU is the same up and down a family (a D8as_v5 costs exactly twice a D4as_v5 at $0.192), so the choice is about behaviour, not price:
- 4 vCPU suits small pools, where granularity matters more than headroom.
- 8 vCPU is the sweet spot for most pools: enough headroom for logon storms, small enough to scale in.
- 16 vCPU (D16as_v5 at $0.768) suits large pools with steady load. Microsoft says returns fall off at about 16 cores, so don't go bigger for multi-session.
Price a whole month for 10 hours a day, 5 days a week (216.5 hours) and the gap between families is clear: a D8as_v5 host costs about $83, an E8as_v5 about $109 and a B8ms about $72. Put your own users, hours and sizes into the AVD cost calculator to compare full estimates.
When the VM size turns out to be wrong
The first size is a hypothesis. The signals that tell you to change it:
- CPU high, memory free: lower the session limit, or move up a size in the same family.
- Memory paging, CPU free: move from D-series to E-series, or lower the session limit and compare cost per user.
- Both low at peak: you're paying for capacity nobody uses. Drop a size or raise the session limit.
- Graphics stutter at high resolution: CPU-only hosts encode the display in software, and Microsoft says users with more than 3840 × 2160 total resolution can see artifacts. That's a GPU question: see GPU VMs for Azure Virtual Desktop.
Changing a session host's size means deallocating it, so do it in a maintenance window, one host at a time, with the host in drain mode.
Atlas AVD watches for the third case. Adaptive SKU flags pools that consistently run well under the capacity their VM size provides and recommends a smaller size with the projected monthly saving, and Adaptive Density™ adjusts each pool's session limit from real demand so the size and the density stay matched.
FAQ
What is the best VM size for Azure Virtual Desktop?
For most pooled desktops, an 8 vCPU D-series VM such as D8as_v5 or D8s_v5, with 32 GB of RAM. Use E-series when memory is the bottleneck and GPU sizes for CAD, 3D and video work.
Should I use D-series or E-series for AVD?
Start with D-series. Move to E-series only when pilot data shows hosts paging while CPU has room. On an 8 vCPU host, E-series is cheaper per user once memory would otherwise limit a D-series host to fewer than about 15 sessions.
Can I use B-series burstable VMs for Azure Virtual Desktop?
For lightly used personal desktops and test pools, yes. For multi-session hosts, no: a busy pool drains the CPU credits early in the day, and the VM is then throttled to its baseline, which is 17% of CPU on a B8ms.
Are AMD or Intel VMs better for AVD?
Both work well. The AMD (Dasv5) and Intel (Dsv5) sizes are priced the same in our calculator, so pick whichever is available in your region and test it in the pilot.
Is 4 vCPU enough for an AVD session host?
For small pools, yes. Microsoft treats 4 cores as the minimum for a stable multi-session host. Most pools are better on 8 vCPU, which absorbs logon storms better and still scales in easily.
Do I need v6 or v7 VM sizes for AVD?
No, v5 sizes are fully supported. v6 and v7 can offer better price-performance, but they need Generation 2 VMs, Trusted Launch and an NVMe disk controller, so plan the move as a conversion rather than a simple resize.
Last updated 9 November 2026. Microsoft details are drawn from Microsoft Learn as of November 2026: Session host virtual machine sizing guidelines, the B-series CPU credit model, the Bv1-series and Bsv2-series size pages, and Azure VM sizes retirement. VM prices are approximate pay-as-you-go rates; check the Azure pricing page for your region.