A few Words about Siemens NX Perfomance – CPU, Graphics Adapter, Memory, Multi-Core

By | 10/28/2016

    Processor performance

    Although raw processor speed has a major impact on system performance, other factors also contribute to overall performance; for example, the type of disk drive (SCSI, ATA, or Serial ATA), disk speed, memory speed, graphics adapter, and bus speeds. The general rule is that “the faster the processor, the better the performance is,” but this only applies when comparing like architectures. For example, it is difficult to arrive at performance expectations for an Intel processor when compared to an AMD processor just by looking at their respective processor speeds. There is also a general trend today to de-emphasize processor speeds and move to multi-core processors, which actually can have lower processor speeds.


    Symmetric Multiprocessing (SMP) is supported in NX mostly via Parasolid, although a small number of NX capabilities have some threading. In general, it is not possible to quote a figure for the general performance improvement achieved by using SMP, since this improvement depends on the nature of the operations you are performing. You need to evaluate your actual performance gains using your own models. Functional areas that are SMP enabled in Parasolid include:

  • Validity checking
  • Boolean operations
  • Wireframe
  • Rendering
  • Hidden line rendering
  • Closest approach
  • Faceting
  • Mass properties

    SMP is enabled by default with the variable UGII_SMP_ENABLE, which is located in the ugii_env_ug.dat file.


    Multi-core processors are similar to SMP because there are two or more actual processor cores but they are delivered in single processor packages. Siemens PLM Software has found that multi-core performance characteristics are similar to SMP. The one advantage of multi-core processors over SMP is that this technology has proliferated much faster than SMP and is now common in workstations, servers, and laptops.

    parasolidMulti-core technology is complex and, depending on the configuration, can actually have a negative impact on performance. This is due to the potential conflict of multiple cores sharing system resources, such as cache, memory, and bus bandwidth, as well the need for the system to manage and control an increasing number of cores. Increasing the number of cores does not always translate into better performance. Although additional cores can improve NX performance, processor speed is still a vital measurement of NX performance. Many systems enable you to turn off cores via the bios, which can enable you to compare performance with a different number of cores that are active. Some users may find that turning off some cores will actually improve performance. One micro-architecture (Intel) even does this automatically, shutting down unused cores and increasing the clock speed of the others. The hardware vendors continue to improve their processor micro-architectures to better address the limitations of older multi-core technologies. New subsystems better integrate memory and other peripherals directly to the processors, resulting in major performance improvements. Buses are being eliminated, cores are better managed, and channel speeds continue to improve. In summary:

  • Turn SMP on only if you have an SMP system. Having it on in a single-processor system incurs a slight overhead.
  • Turn SMP on if you have a multi-core system.
  • Never assume that by simply adding more cores you will see better performance. Always test first.


    For Windows 7, the minimum amount of memory is 4 GB, but we recommend 8 GB or 16 GB of memory as a starting point. Large models and assemblies or running multiple processes concurrently could boost the required memory for adequate performance.

    Graphics adapters

    All the NX certified systems contain graphics adapters that meet all Siemens PLM Software requirements and are fully supported by our hardware partners. The graphics adapters supported are carefully selected by working with our OEM partners as well as our graphics vendor partners. We do not recommend low-end, consumer, or game cards, since these graphics devices are developed for the DirectX market and are not well supported under OpenGL.STEP

    Because a majority of platform/hardware problems are graphics related, it is critical that all the graphics adapters that NX supports are designed for OpenGL and have the highest level of support from our hardware vendors. We highly recommend that you only use supported graphics adapters and Siemens PLM Software certified drivers. If you are running Microsoft Windows 7 you will require graphics adapters with more on-board memory, especially when AERO (the enhanced 3D feature) is turned on. The minimum recommended graphics on-board memory is 256 MB, and although graphics adapters with less memory will work, the performance may not be adequate, even with AERO turned off. If you have high-end graphics requirements, you will need to consider graphics adapters with 512 MB or higher on-board memory.

This article is created based on the Siemens PLM materials.

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