Ansys on 2 x Dual Core Machine?
Ansys on 2 x Dual Core Machine?
(OP)
Hi,
Does anyone have any suggestions for getting Ansys to fully utilise all the processing power of a 2 x Dual Core machine (4 x Xeon E5335's).
In Design Modeller it only ever seems to use 25% and in Simulation 50%.
I think this may be a limitation of the licensing/software. But I was wondering if anyone had tried to lump the processers together so windows only shows them as one processor and hopefully tricks Ansys into using all the processing power available.
Hope that makes sense...Rich
Does anyone have any suggestions for getting Ansys to fully utilise all the processing power of a 2 x Dual Core machine (4 x Xeon E5335's).
In Design Modeller it only ever seems to use 25% and in Simulation 50%.
I think this may be a limitation of the licensing/software. But I was wondering if anyone had tried to lump the processers together so windows only shows them as one processor and hopefully tricks Ansys into using all the processing power available.
Hope that makes sense...Rich





RE: Ansys on 2 x Dual Core Machine?
I've never seen design modeler utilze more than one processor for any process.
Best,
-Brian
RE: Ansys on 2 x Dual Core Machine?
There is possibly a work around as I just got off the phone with Intel tech support and there supposedly is an advanced bios setting which allows you to turn off the multi-core architecture and treat the entire cpu as one core.
If anyone else has tried this I would be interested to get some feedback. It's pretty ridiculous that the software limits the use of all available processing power.
Will feedback soon...
Cheers...
RE: Ansys on 2 x Dual Core Machine?
I switched the multi-core option off in the BIOS. Seemed to work. Unfortunately it still shows 2 cores - a function of an old bios but Design Modeller ran up to 50% of CPU rather the 25% usage it was showing with the quad core split.
Now limited by file I/O speed. If anyone else has tested this out please share your findings...
Cheers
RE: Ansys on 2 x Dual Core Machine?
1- of course it shows 2 processors if that's what is physically installed. "Cores" are a trick but physical processors are not. You can NOT combine two physical processors as being seen as only one by the O.S. However, having reduced to two processors you can now allow Ansys to take full advantage of them, for the processes which really are multi-proc-ready, without paying for the multi-proc license.
2- file swapping: in my experience, best performance is with SCSI subsystems. It doesn't matter if you have very fast SATA or things like that: The latest SCSI subsystems do are lightyears ahead. The fastest HD even nowadays are designed for SCSI subsystems. If you are already lucky enough to have the fastest possible SCSI system, then...
2a- expand RAM as much as you can (but max 3GB on Win32 systems, included Vista)
2b- use, if it's not already so, the /3GB switch in the "boot.ini" (only for Windows systems)
2c- consider using a 64bits architecture, and return to point 2a...
However, for many tasks ANSYS does write "a lot" on disk, independently from the RAM quantity. And if you have a 2GB result file, it will remain long to write even with 32GB RAM...
Regards
RE: Ansys on 2 x Dual Core Machine?
Which BIOS option allowed you to map both cores into one processor as seen by the OS? I have an AMD based workstation and don't have the parallel licensing option with Ansys. Perhaps I have this option as well in my system and just don't know about it yet...
Thanks,
-Brian
RE: Ansys on 2 x Dual Core Machine?
The BIOS setting on our machine was under
Advanced > Advanced Processor Options > Core-Multi Processing.
Although I can't say that we noticed a vast improvement. As cbrn pointed out the disk read/write times are a limiting factor for big analyses with big result files. Our machine does have a raid mirror which I think is affecting our runtime speeds.
Cheers, Rich
RE: Ansys on 2 x Dual Core Machine?