> 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 <https://HALB-VIP/userportal/> 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 %}

<figure><img src="/files/N775Njkbw6QyIUYj18sZ" alt=""><figcaption></figcaption></figure>

## **250 users**

Parallels RAS was deployed on VMware vSphere 6.5 on Windows 2016 Server as follows:&#x20;

| 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: <https://download.parallels.com/ras/v18/docs/en\\_US/Parallels-RAS-Scalability-Testing-Login-VSI.pdf>

## **500 users**

Parallels RAS was deployed on VMware vSphere 6.5 on Windows 2016 Server as follows:&#x20;

| 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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