Memory Utilization with Flow-3D

ck5285 · February 11, 2010, 20:31

All
noticed that by using SMP version the CPU utilization is high (without GMO option turn on) but memory utilization is always low at around 200MB-400MB. so I wonder why the program didn't fully utilize the memory size that my system have (32GB RAM) in order to provide additional speed up in simulation time?Thanks.

MuxaB · February 25, 2010, 12:25

Quote:

Originally Posted by ck5285

All
noticed that by using SMP version the CPU utilization is high (without GMO option turn on) but memory utilization is always low at around 200MB-400MB. so I wonder why the program didn't fully utilize the memory size that my system have (32GB RAM) in order to provide additional speed up in simulation time?Thanks.

The memory usage is largely determined by the mesh size and the selection of physical and numerical options. SMP parallelization in FLOW-3D does not add much to this, although it could have been done in a way that would consume much more memory - in proportion to the number of threads used, but this does not seem reasonable.

ck5285 · February 28, 2010, 23:50

Michael
so can you advice what physic, solver setting & mesh size will allow full memory utilization? btw, should i expected simulation time speed up if the memory utilization is 100%?

MuxaB · March 1, 2010, 11:22

Quote:

Originally Posted by ck5285

Michael
so can you advice what physic, solver setting & mesh size will allow full memory utilization? btw, should i expected simulation time speed up if the memory utilization is 100%?

I am not sure what you mean by 100% memory utilization. Do you want FLOW-3D to use all 32 Gb of memory? If you are asking rather what options have been SMP parallelized, please see this article http://www.flow3d.com/resources/news...fall07_06.html.

shstyle0 · May 12, 2010, 03:17

I don't think using more memory would speed up the simulation. memory is like a hard drive, a storage. Using 100% memory would mean you have 32 Gb for your computer to remember, which means your cpu would have more stuff to calculate.
If you use more cells (smaller cells), then your memory usage would go up, but the calculation time will be much longer I believe.

February 11, 2010, 20:31	Memory Utilization with Flow-3D	#1
ck5285 Senior Member Join Date: Mar 2009 Posts: 129 Rep Power: 17	All noticed that by using SMP version the CPU utilization is high (without GMO option turn on) but memory utilization is always low at around 200MB-400MB. so I wonder why the program didn't fully utilize the memory size that my system have (32GB RAM) in order to provide additional speed up in simulation time?Thanks.

February 28, 2010, 23:50		#3
ck5285 Senior Member Join Date: Mar 2009 Posts: 129 Rep Power: 17	Michael so can you advice what physic, solver setting & mesh size will allow full memory utilization? btw, should i expected simulation time speed up if the memory utilization is 100%? dbz112233 likes this.

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May 12, 2010, 03:17	re	#5
shstyle0 New Member Seunghyun Yoon Join Date: Jan 2010 Posts: 6 Rep Power: 16	I don't think using more memory would speed up the simulation. memory is like a hard drive, a storage. Using 100% memory would mean you have 32 Gb for your computer to remember, which means your cpu would have more stuff to calculate. If you use more cells (smaller cells), then your memory usage would go up, but the calculation time will be much longer I believe.