RDS Server Sizing Calculator: How Many Users Can a Remote Desktop Server Handle?
Companies that run ERP or accounting software over Remote Desktop (RDS) all ask the same question: how many users can one server handle comfortably? This RDS server sizing calculator estimates the number of session hosts, plus vCPU and RAM per host, from concurrent users, workload type and profile storage per user. The remote desktop session host sizing logic is based on Microsoft’s published guidance for multi-session hosts, and the formula is explained below so the result is a checkable estimate rather than a black box.
All calculations run in your browser; nothing you enter is sent to a server.
Turn the Result Into a Cloud Server Setup
Once the number of session hosts and resources is clear, the next step is the right server configuration. The MAV Cloud team can help refine the calculated values for your user count and software.
What is RDS, and why do companies run ERP over it?
RDS (Remote Desktop Services) runs applications on a Windows Server that users reach through a remote desktop session. It is also known as a terminal server: several users open their own sessions on the same machine.
Many Turkish SMEs use their ERP and accounting packages this way. Because the application runs close to its database, users connecting from branches or from home get acceptable performance even over a slow line. Updates happen in one place and data never lands on user laptops.
The weak spot of this model is shared resources. Every user on the host shares the same CPU and memory, so an undersized server slows everyone down during month-end close or heavy reporting.
How many users per vCPU can RDS handle?
How many users one vCPU supports depends on what those users do on the server. Microsoft’s guidance for multi-session hosts sorts workloads into four classes and gives a maximum number of users per vCPU for each (Microsoft, session host sizing guidelines).
- Light (6 users per vCPU): data entry, simple forms, command-line tools.
- Medium (4 users per vCPU): ERP and accounting screens, office apps, light browsing. Most ERP use falls into this class.
- Heavy (2 users per vCPU): heavy reporting, large Excel files, many browser tabs and development tools.
- Power (1 user per vCPU): graphic design, CAD, data analysis and other CPU- and memory-intensive apps.
The calculator works out total vCPU from the selected class. The minimum size for each session host is 8 vCPU, 16 GB RAM and a 32 GB OS disk; for power users the floor is 6 vCPU and 56 GB RAM.
Terminal server sizing: RAM and splitting hosts
RAM follows from vCPU: 2 GB per vCPU for light, medium and heavy workloads (at least 16 GB), and about 9.3 GB per vCPU for power workloads (at least 56 GB). Tying memory to vCPU this way keeps the host balanced.
Microsoft recommends keeping multi-session hosts between 6 and 24 vCPUs. When total demand goes above 24 vCPU, the calculator splits the load across several session hosts and rounds vCPU per host up to an even number.
The table below uses the calculator’s own formula:
| Concurrent users | Workload | Hosts × vCPU / RAM |
|---|---|---|
| 10 | Light | 1 × 8 vCPU / 16 GB |
| 25 | Medium | 1 × 8 vCPU / 16 GB |
| 60 | Medium | 1 × 16 vCPU / 32 GB |
| 150 | Medium | 2 × 20 vCPU / 40 GB |
| 40 | Heavy | 1 × 20 vCPU / 40 GB |
| 5 | Power | 1 × 6 vCPU / 56 GB |
In the first two rows the user count is small, so the minimum host size applies. 150 medium users need about 38 vCPU; that is above the 24 vCPU limit, so the load is split across two 20 vCPU hosts.
How to read the result
The result shows the number of session hosts, vCPU, RAM and OS disk per host, total profile storage, and total vCPU and RAM across all hosts. Treat these values as a starting size and confirm them with a pilot.
Profile storage is the number of users multiplied by profile size per user. With the default 30 GB, 25 users need 750 GB; Microsoft also recommends at least 30 GB of profile storage per user. The final note on the result screen is a reminder that the ERP database belongs on a separate server, not on the session host.
ERP server requirements: why the database needs its own server
The ERP database should run on a separate server, not on the session host. When user sessions and the database engine share the same CPU, memory and disk, a spike on one side slows down the other.
Databases generate heavy disk I/O; while a month-end report runs, session screens open slowly. Backups get simpler too: the database is backed up independently, and a restore does not disrupt user sessions.
ERP requirements differ from one product to another, so size the database server from the software vendor’s published system requirements, not with this calculator.
Before Moving Your RDS Server to the Cloud
Real usage data from your on-premises terminal server is the most reliable way to size the new cloud setup. Current usage can be measured and compared with the calculated values.
User profiles and storage
With more than one session host, user profiles should not be tied to a single server. Profile containers (such as FSLogix) or user profile disks keep the profile on shared storage, so users see the same desktop whichever host they land on.
When sizing profile storage, account for what builds up per user: desktop files, documents and mail cache. The default 30 GB is a reasonable start for most office users; raise it for users who keep a large mailbox cache.
Licensing reminder: RDS CALs
On top of the Windows Server license, every user or device connecting to RDS needs an RDS Client Access License (CAL). Choose per-user or per-device licensing based on how many devices your staff connect from.
If the same person connects from a laptop, a home PC and a tablet, per-user licensing usually fits better; where shift teams share the same PCs, per-device licensing comes forward. ERP user licenses are separate.
Pilot testing and monitoring
Confirm the calculated size with a short pilot using real users. Move part of the team to the new host and measure during busy days.
Three indicators matter most. CPU ready time shows how long the virtual machine waits for a physical CPU. RAM pressure shows when memory fills up and paging to disk begins. Login time exposes profile loading and group policy issues before users start to complain.
Common sizing mistakes
- Counting all staff as concurrent users: a company with 80 employees usually has fewer people connected at the same time; size for concurrent sessions.
- Putting the database on the session host: it looks cheaper at first, but becomes the most frequent source of performance complaints as users grow.
- Relying on one large server: above 24 vCPU a single host scales poorly and stops every user during maintenance.
- Picking too light a workload class: if ERP screens sit alongside heavy Excel and browser use, choose Heavy rather than Medium.
RDS and ERP servers at MAV Cloud
MAV Cloud’s cloud servers run in an Equinix data center on VMware infrastructure. Session hosts and a separate ERP database server can be sized to fit on this platform; options are on the cloud server rental page, and the differences between server types are covered in our VDS vs VPS vs cloud server guide.
When nobody can reach the ERP, the whole company stops. MAV Cloud’s service level agreement sets a monthly 99.9% availability target for cloud server and dedicated server services, with first-response targets of 15 minutes for critical, 1 hour for high, 4 hours for medium and 1 business day for low priority.
Accounting and ERP data are among a company’s most sensitive records. MAV Cloud is certified to ISO/IEC 27001, ISO/IEC 27701, ISO 22301, ISO/IEC 20000 and ISO 9001 (see our certifications). Ongoing patching and configuration after setup are handled under our Windows Server management service.
Frequently Asked Questions
How many users can one remote desktop server handle?
It depends on the workload. Microsoft’s guidance targets 6 users per vCPU for light, 4 for medium and 2 for heavy workloads. An 8 vCPU host with a medium workload supports about 32 concurrent ERP users.
Can the ERP database and RDS run on the same server?
Technically yes for very small setups, but it is not recommended. Because of disk load, locking and backups, run the database on a separate server sized to the vendor’s requirements.
Should I scale up the server or add another host as users grow?
A session host can grow up to 24 vCPU. Beyond that, adding another session host and spreading the load is the healthier option.
How accurate is the calculator?
The result is a starting size based on Microsoft’s guidance. Your software, reporting load and user habits change the real requirement, so confirm it with a pilot.
Is anything I enter stored?
No. The calculation runs in your browser and your inputs are not sent to a server.
Free Assessment of Your Current Setup
Share your user count, software and current server details, and the session host and database server layout can be reviewed together.
If the setup is already clear, the quote link on the result screen is the fastest route.