Adjusting the Visum registry to speed up timetable-based assignment calculation

You can speed up the calculation of timetable-based assignment on computers with more than 12 kernels by changing the registry of your Visum installation.

There is no universally optimal setting, as it depends on the hardware of each user. The following section describes the registry keys whose configuration can help improve computation speed. We recommend that you test different settings. The following description is for Windows 7.

1.  In the Windows task bar, click the Start button.

2.  In the search box, enter Regedit.

3.  Press the Enter key.

The Registration editor opens.

4.  Navigate to HKEY_CURRENT_USER\Software\PTV AG\Vision\Visum\PTV Visum\240\Common\Misc.

5.  Enter the ProcessorInfo key.

6.  In the ProcessorInfo key, enter the keys AvoidMemoryDonationsToOtherProcessors, CoreEnumerationOrder, and NumberOfProcessors of the type REG-DWORD.

Registry key

Description

NumberOfProcessors

Enter the number of physical processors your computer has. The number of kernels is not relevant.

Note

If you enter a higher number of processors than your computer has, you will need more main memory during computation.

CoreEnumeration order

Specifies the distribution of real and virtual kernels across the processors.

  • The value 0 means that the real and virtual kernels are numbered alternately.

Example: A computer has 2 processors and 16 kernels.

Kernels 1 to 8 belong to processor 1. Thereby kernels 1, 3, 5, 7 are real, and kernels 2, 4, 6, 8 are virtual kernels. Kernels 9 to 16 belong to processor 2. Thereby kernels 9, 11, 13, 15 are real, and kernels 10, 12, 14, 16 are virtual kernels.

  • The value 1 means that real and virtual kernels are numbered in two halves. The first half consists of real kernels. The second half consists of the virtual kernels.

Example: A computer has 2 processors and 16 kernels.

Kernels 1, 2, 3, 4, 9, 10, 11, 12 belong to processor 1. Thereby, kernels 1, 2, 3, 4 are real kernels and kernels 9, 10, 11, 12 are virtual kernels. Accordingly, kernels 5, 6, 7, 8, 13, 14, 15, 16 belong to processor 2. Thereby, kernels 5, 6, 7, 8 are real kernels, and kernels 13, 14, 15, 16 are virtual kernels.

Notes

If you do not know your computer's architecture, you will have to try which value leads to the fastest computational results.

The free software CoreInfo, which belongs to Microsoft's SysInternals Suite, can provide information on the processors and kernels of your computer. The analyses results obtained with CoreInfo can help you determine the right settings for your computer.

AvoidMemoryDonationsToOtherProcessors

Specifies the memory exchange between processors.

  • The value 0 means that during computation free memory is exchanged between the processors. For some computers this can slow down the computation process.
  • The value 1 means that the exchange of memory is prevented.

7.  In the ProcessorInfo folder, right-click the key of your choice and from the shortcut menu, choose Edit.

8.  In the Value box, enter the settings of your choice.

9.  Confirm with OK.

The value of the key is changed.