Applies to: @RISK 5.x and Up

 

Why does @RISK use only one CPU even though Multiple CPU is enabled?

 

@RISK may use only one CPU for several reasons:

Heuristic decision: @RISK estimates whether parallel processing will save time.

• If overhead of starting multiple Excel copies outweighs the benefit, it uses one CPU.

Trust macros: It's extremely important to trust the macros of RiskSimMultiCpu8.XLAM especially if you “Require application add-ins to be signed by Trusted Publisher“ in Excel’s Trust Center.

Demo Mode: If Demo Mode is selected in the ribbon or Simulation Settings » View, only one CPU is used.

• Deselect Demo Mode to enable multiple CPUs.

Microsoft Project simulations: Project-based simulations always use one CPU, though the accelerated engine can speed things up.

Disabled add-ins:

If RiskSimMultiCpu7.xla, RiskSimMultiCpu8.xla, or RiskSimMultiCpu8.xlam is disabled in Excel, multiple CPUs will not run.

• Check via File » Options » Add-Ins » Manage: Disabled Items.
• For XLAM files, ensure macros are trusted in the Trust Center.

Version changes:

Starting with @RISK 6.3, the software is more conservative.

• Small simulations that previously ran on multiple CPUs may now run on one, depending on recalculation time.

 

Related Article:

CPUs Used by @RISK 7.x