> For the complete documentation index, see [llms.txt](https://docs.parallels.com/landing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.parallels.com/landing/ras-reference-architecture/v20/capacity-considerations.md).
# Capacity Considerations
Parallels conducted in-house Parallels RAS scalability testing using a total of two HP DL360 consisting of the following hardware components:
| Component | Description |
| --------- | ---------------------------------------------- |
| CPU | 2x Xeon E5-2670 v1, 2.6GHz, 20 MB L3, 115W TDP |
| RAM | 128 GB, 16x 8 GB Micron DDR-4-2100 at 1600MHz |
| HDD | Western Digital Blue 1 TB SSD |
The following Parallels RAS lab environment was used:
* A farm consists of 1 site.
* Single hop DMZ.
* Each Secure Gateway can host 1200 sessions in Gateway SSL mode (enumeration and proxying RDP session in SSL + User Portal).
* Each Secure Gateway has User Portal enabled and balanced by HALB using the same port 443 (When using URL the incoming connections will be distributed appropriately because SSL session persistence is in a place).
{% hint style="info" %}
**Note:** To enable SSL and User Portal, a server certificate must be installed.
{% endhint %}
## **250 users**
Parallels RAS was deployed on VMware vSphere 6.5 on Windows 2016 Server as follows:
| Parallels RAS Component | Total VMs | vCPU in Each VM | RAM in Each VM |
| -------------------------------- | --------- | --------------- | -------------- |
| RAS Connection Broker | 2 | 2 | 4 GB |
| RAS Secure Gateway | 2 | 2 | 4 GB |
| High Availability Load Balancing | 2 | 1 | 2 GB |
| RD Session Host | 6 | 6 | 24 GB |
* All components doubled for redundancy.
* RDSH N+1 for redundancy.
The above configuration has been tested with both our internal tools and Login VSI. For more details, you could read the **Parallels RAS Scalability Testing with Login VSI** paper, which is available at the following URL:
## **500 users**
Parallels RAS was deployed on VMware vSphere 6.5 on Windows 2016 Server as follows:
| Parallels RAS Component | Total VMs | vCPU in Each VM | RAM in Each VM |
| -------------------------------- | --------- | --------------- | -------------- |
| RAS Connection Broker | 2 | 2 | 4 GB |
| RAS Secure Gateway | 2 | 2 | 4 GB |
| High Availability Load Balancing | 2 | 1 | 2 GB |
| RD Session Host | 12 | 6 | 24 GB |
* All components doubled for redundancy.
* RDSH N+2 for redundancy.
**1000 users**
| Parallels RAS Component | Total VMs | vCPU in Each VM | RAM in Each VM |
| -------------------------------- | --------- | --------------- | -------------- |
| RAS Connection Broker | 2 | 2 | 4 GB |
| RAS Secure Gateway | 2 | 2 | 4 GB |
| High Availability Load Balancing | 2 | 1 | 2 GB |
| RD Session Host | 24 | 6 | 24 GB |
* All components doubled for redundancy.
* RDSH N+4 for redundancy.
---
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