Q: Is ArchiCAD multi-threaded?
A: ArchiCAD is not multi-threaded as a whole, but parts of ArchiCAD are - typically functions added recently. In ArchiCAD 10, these are the functions that support multi-threading:
*
LightWorks rendering engine
* File saving with data compressing option
* Placing PDF files as drawing (visual feedback when positioning the drawing)
Q: Is rendering with LightWorks twice as fast on a dual-core processor?
A: Creating a rendered image involves separate steps. When you start a "Photorender projection", first the 3D model of your project is generated in the 3D window, then the model is converted into LightWorks data format, and only the last step is the so-called "rendering", when the lines of the image are starting to appear on screen. Only this last phase is multi-threaded.
Q: Can LightWorks use 4 processors?
A: Yes. Theoretically, LightWorks can use as many processors as you have
Q: I never use LightWorks. Does it make any sense at all to buy dual-core computer?
A: Yes. Even though ArchiCAD will typically use only 50% percent of the CPU resources, you are always running other tasks as well - invisible (or not so invisible) operating systems tasks, or user tasks such as another copy of ArchiCAD, for example. During processor-heavy activities (e.g. 3D model or section generating, publishing, updating layouts) when ArchiCAD's CPU usage maxes out, your system will still be responsive when you try to use other applications. For example, when you are updating drawings that are linked into another ArchiCAD project, the Background ArchiCAD - which is another copy of ArchiCAD - will not keep you from working on in the open project.
Q: I have a dual-core computer, and when I am using ArchiCAD, the processors max out at 50%. They never reach 100%.
A: Due to Multitasking (see above), the operating system distributes program tasks evenly between processors, even if there is a single thread of tasks. So a single-thread application will behave like this on a dual core machine. On a 4-core computer all four cores will reach 25% instead of one running at 100% and three sitting idle - the latter would cause one of the processors overheating while there is plenty of resource left.
Q: I am rendering with LightWorks, but it still seems that both processors stop at 50%
A: There are areas in LightWorks that are not multi-threaded. Depending on settings, it is normal that LightWorks renders with only one thread. See more in the LightWorks article
Q: When will ArchiCAD be fully multi-threaded?
A: There are plans to include more multi-threaded features in future versions of ArchiCAD, but ArchiCAD will not be a fully multi-threaded application at any time soon. This is partly because re-writing the ArchiCAD code to support multi-threading is a huge task, and there are areas where it would not cause a dramatic performance increase. Graphisoft will focus on the areas where multi-threading brings the most benefit.
Q: Does the amount of memory (RAM) matter when using a multiprocessing computer?
A: Yes. You will only realize the full benefit of the power of the two, four or more processors in your computer if you have sufficient memory from which they will run programs and access data. With insufficient memory, too much time will be wasted obtaining information from the much slower disk drives. Even with the new disk drives that should arrive on the market in 2007 which will have much larger onboard memory caches (memory attached to the disk to speed access), main memory is still very essential to performance. For example, if you need 1 GB on a computer with a single processor... that same 1 GB would be quite insufficient on a four processor MacPro, as all four processors would be trying to fit their programs and data into that memory space, and would thus be using virtual memory (your hard disks) for the overflow, vastly slowing down all work.
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Szerkesztette: Hrváthg 2007. 04. 20. 15:02 -kor