Understanding Altair Unit Licensing & Usage Display

Altair Unit Licensing – A Quick Guide

To clarify how Altair Units (AUs) work:

• Each Altair application or solver consumes a specific number of Altair Units (AUs).
• 1 AU equals 1000 license features.
• You can run any Altair product as long as enough license features are available and the required product license features are included in your license.

Examples:

• HyperMesh: 21 AUs → 21,000 license features
• OptiStruct: At least 50 AUs → 50,000 license features

Leveling Explained

Altair uses a licensing mechanism called Leveling, which optimizes license usage across multiple applications.

When running multiple applications under the same host and username, only the highest AU cost is drawn from the license.

Example:

• If a user starts HyperMesh (21 AUs) and then opens HyperGraph (6 AUs) on the same machine under the same username, the total draw remains 21,000 license features.
• The same applies to opening multiple instances of the same application—only the highest AU cost is considered.

Stacking Explained

Leveling does not apply in the following cases, and AU usage stacks:

• When different users run the same application (e.g., two users running HyperMesh = 21 + 21 AUs).
• For certain products—including APA applications—leveling is not supported.
  → In these cases, multiple instances on the same user/host will add up.
  Example: Running two instances of a 20 AU APA app = 40 AUs total.

Decay Explained

Altair implements a decay function when multiple solver jobs run concurrently from the same license server.

• This decay reduces total AU draw by applying a multiplier to secondary jobs of the same solver.

Example

1. Launch HyperMesh (21 AUs)
   → Draw = 21 AUs
2. Add Radioss (30 AUs)
   → Draw = 30 AUs (replaces 21 AUs since it's higher due to leveling)
3. Add OptiStruct (50 AUs)
   → Draw = 50 AUs (replaces 30 AUs due to leveling)
4. Add a second OptiStruct job
   → Total draw = 95 AUs
   (50 AUs + 0.9 × 50 AUs due to decay)

How Usage Is Displayed (Altair One & ALMUtil)

When checking license usage through Altair One or ALMUtil, you might see higher AU counts than expected.

This is because the displayed usage is before leveling is applied.

To view the actual AU draw after leveling, click:

"Collapse on Share String"

This option is available in both Altair One and ALMUtil (under the License Usage tab).

Before collapse:

After collapse:

Final Notes

• Both tools (Altair One & ALMUtil) show similar license usage info.
• Always use "Collapse on Share String" to get accurate post-leveling data.

For more detailed information, you can refer to the official Altair Licensing Guide linked below:

Recommended Sections:

• Unit draw per application: pages 11–18
• Solver unit draw: page 21

Altair Units Licensing Guide