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kb:parallel [2018/01/23 19:25] – enviadminkb:parallel [2021/04/21 09:38] (current) – [Practical Issues] enviadmin
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 Many people have a concept what parallel computing is, and they want to have it in their applications, but as this is a relatively new area of computing, it contains many misunderstandings and misleading expectations we try to clarify in this Knowledge Base. Many people have a concept what parallel computing is, and they want to have it in their applications, but as this is a relatively new area of computing, it contains many misunderstandings and misleading expectations we try to clarify in this Knowledge Base.
  
-===== Changed Pressure Solver  ===== 
-With the introduction of Parallel Computing, it was neccessary to rewrite the pressure-solver used to obtain the wind field. 
  
-However, it can be noted, that the new parallel solver produces slightly different results compared to the old, sequential solver. +====== Q&A on Parallel Computing with ENVI-met  ======
-If you want to keep the old solver for compatibility reasons, please add the followingg lines in your .SIM files:+
  
-[SORMODE] +Please read the following sections carefully to get most of the new options of ENVI-met.
-SOR solver (0: classic, 1:parallel)= 0 +
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-This will be more clearer in the next release of ENVI-met. +
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-So, please read the following sections carefully to get most of the new options of ENVI-met.+
  
 ~~QNA~~ ~~QNA~~
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 The larger the supermarket gets and the more complicated the items are to find (large models, complex calculation tasks), the more you benefit from the help of your friends. Ideally, they all require the same amount of time to fetch the items and come back to you in one block. That's the situation when parallel work will be most efficient.  The larger the supermarket gets and the more complicated the items are to find (large models, complex calculation tasks), the more you benefit from the help of your friends. Ideally, they all require the same amount of time to fetch the items and come back to you in one block. That's the situation when parallel work will be most efficient. 
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 +??? Can I run ENVI-met on any Supercomputer ?
 +Yes, if the Supercomputer runs under or supports WINDOWS. If the operating system is LINUX or other, you cannot run ENVI-met as there is no LINUX version so far.
  
  
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 ??? I started an ENVI-met without any specific CPU usage instructions. How many CPUs cores will it use? ??? I started an ENVI-met without any specific CPU usage instructions. How many CPUs cores will it use?
  
-The default setting is to use all available CPU cores.+The default setting is to use all available CPU cores, that are assigned by the operating system. How many cores this will actually be in the end, will not only depend on your computer, but also on the amount of other applications running parallel to ENVI-met. Also, the amount of cores is assigned dynamically by WINDOWS and is also requested dynamically by ENVI-met depending on the specific simulation task. In other words: If ENVI-met is operating in a model section that is not parallel, it will not request more than one core.