High-Performance Computing at the NIH

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Connecting to Helix with FastX

About FastX

FastX, from StarNet Communications, is an X server that allows users to connect over the Internet and work with even the most demanding remote hosted Linux/Unix applications at LAN speed. It is recommended for users who telework or are on the go, because FastX sessions are persistent and it utilizes integrated secure shell (SSH). The secure shell is also compatible with PuTTY.

Installing FastX

Helix users can download and install a licensed version of FastX on their Windows PC or Mac by following these one-time instructions.

1. Obtain FastX Activation Key

Obtain the FastX activation key by logging on to Helix and type the command fastxlicense at the helix prompt. The output from this command will be used in step 3 and is necessary to activate FastX on your PC.

helix% fastxlicense

If you do not already have a way to login to Helix to run this command you should first install PuTTY, a free SSH terminal client for Windows.

NOTE: Your helix username and password are the same as your NIH account and password.

2. Download the FastX Client

Follow this link to download the FastX installation archive to your Windows computer:


Follow this link to download the FastX image file to your Mac computer:


3. Install the FastX Client

For Windows:
Locate where fastx_current.exe was downloaded. One way to do this is to go to the Start menu, click Find -> Files or Folders and type fastx_current.exe and click Find Now.

Once you have located fastx_current.exe, double click the file to start the InstallShield Wizard. The Wizard will guide you through the installation process.

For Macs:
Locate where FastX.dmg was downloaded. Double-click on file to mount the image, then drag the FastX icon to the Applications folder.

4. Start FastX

To start FastX for Windows, click on Start -> All Programs -> StarNet -> FastX

To start FastX for Macs, navigate to the Applications folder and double-click on the FastX icon.

IMPORTANT: On start-up, you will be prompted for the FastX activation key, you should see a window similar to the image below. Be sure that "License Server" is showing before entering the information obtained in step 1, then click "ok".


5. Creating a FastX Connection

IMPORTANT FOR MAC USERS: When creating a connection, please use "Single Application" mode because Gnome is not optimized for the MacOS. It will slow down performance by FastX.

Launching a FastX connection is a 2 step process. First you must create a connection to the FastX server, then reconnect to an existing session or start a new session:

Creating a Connection

Windows Users: Start -> All Programs -> StarNet -> FastX
Mac Users: Double-click on the FastX icon in the Applications folder

Click on the green PLUS icon in the left hand corner to create a new session.


The "Edit SSH Connection" Window should display. Click the "General" tab and enter the following:

  • Name* = helix_fastx (or the name of your choice)
  • Host* = helix.nih.gov
  • Port* = 22

fastx_config1 (40K)

Next, click the "Advanced" tab and enter the following:

  • SCI = /opt/fastx_server/bin/fastx_sci]

fastx_config2 (40K)

Click the "Save" button. The following window should appear:


Double-click on the session name to login:


6. Starting a Session

Once connected, your running sessions will appear on the right hand side of the window. Sessions listed continue to run on the server unless terminated by the user. You can reconnect to a running session by double-clicking on the session or you can start a new session.


You can start a new session as either a desktop window or a single application. A gnome-session works best in a desktop window. If you just want an xterm or application window, such as mathematica, the single application window is best.

Ex. Gnome-session 1

For a terminal window in a gnome-session, click on Applications -> System Tools -> Terminal

Ex. Gnome-session 2

Ex. Single application xterm session 1

At the helix prompt, you can issue any command, such as, matlab& to get started.

Ex. Single application xterm session 2

Helix X Applications

Once FastX is installed on your machine, you can try some Helix X applications such as matlab, mathematica, quest, etc, by logging in to helix/biowulf. If you have questions about or problems using FastX, see the FastX before contacting the Helix staff.