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-   -   FloWorks and CPU usage? (http://www.cfd-online.com/Forums/floefd-floworks-flotherm/73555-floworks-cpu-usage.html)

cvp_dk March 11, 2010 03:47

FloWorks and CPU usage?
 
Hi all
I using FloWorks together with SolidWorks, And I have just received a new computer, itís a dual CPU configuration (total 8 cores, 12Gb ram etc.)
Now I was of course hoping that my simulation would run faster with this new computer.
But running the simulation only results in max 50% CPU usage? (And that is max. most of the time it shifts between 13-41%)
When starting the simulation it is asking how many CPUís (Cores)to use and is suggesting 8 by itself, but I donít see that happening.
Any one that can help getting the CPU usage up?


OS.: Windows7 X64
SolidWorks Premium 2010 X64 SP2.1
Flow Simulation 2010 SP2.0 Build:1148

BR.
Christian

kskong December 8, 2010 14:00

Hi, I am facing exactly the same problem as yours. Just wondering if you have figured out how to solve the problem so that we can maximize the CPU usage?
Thanks! :)

cvp_dk December 13, 2010 02:01

Hi kskong
No sorry i have not been able to solve the problem.
We have purchased a new CFD tool instead J, we are only using Flowoks for some simple backpressure calculations now.
And AVL Fire for the more advanced calculations.

BR.
Christian

Vader January 2, 2011 12:17

I've found that I can load up all the threads by starting multiple sessions of Flow Sim. This works well for me since I've usually got a solution space to work through trying different features and values of the parameters.

Scott

JZB March 23, 2011 10:17

Quote:

Originally Posted by cvp_dk (Post 249502)
Hi all
I using FloWorks together with SolidWorks, And I have just received a new computer, itís a dual CPU configuration (total 8 cores, 12Gb ram etc.)
Now I was of course hoping that my simulation would run faster with this new computer.
But running the simulation only results in max 50% CPU usage? (And that is max. most of the time it shifts between 13-41%)
When starting the simulation it is asking how many CPUís (Cores)to use and is suggesting 8 by itself, but I donít see that happening.
Any one that can help getting the CPU usage up?


OS.: Windows7 X64
SolidWorks Premium 2010 X64 SP2.1
Flow Simulation 2010 SP2.0 Build:1148

BR.
Christian

Hi
I'd check to see if you CPU's are using hyperthreading. I had a problem with a different CFD code when hyperthreading was enabled on an i7 duo core CPU. Effectively the computer had two physical cores but the machine could see 4 cores and the software could not cope with hyperthreading technology. Would try asking the vender as well
JZB :)

Boris_M March 25, 2011 03:46

Hi all,
there shouldn't be a problem like that. If this exist you should contact your support.
In any case Hyperthreading shouldn't be used with any CFD or FEA code as the code tries to use all the cores you tell him which are physically not there and this is causing problems. Imagine a teacher tells you you have an imaginary second brain and now use it for your math homework to get it done faster. Good luck with that too.
This is basically tricking the processor while he waits for input and another programm could use the computation power to do something in that time. So you can compare it to the following real life case of: You are waiting for some customer to call you back for some information for his consulting work you do for him but in the mean time you'll do some other things instead of sitting dead in front of the phone waiting.

So you can use CPU power if a process is another process is waiting for example to get data from the slower hard drive but if all processors are used by the same programm then you can expect that the programm is programmed to work that way efficiently and therfore using all the cores more or less equally so you cannot tell it that it can use double the cores that in reality don't exist.

@ cvp_dk: may I ask what applications you use AVL and Floworks for?

Regards,
Boris

cvp_dk June 20, 2011 08:57

Hi Boris
Sorry for the very late reply.
Yes you may ask. We are using AVL fire for multiface simulations involving Urea and exhaust gas.
And we are using Floworks for the more simple stuf like pressure drop calculations of silencers.

Br. Christian


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