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about the limitation of RAM when using HFSS

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Full Member level 3
Aug 12, 2005
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My computer have 3.6GB ram,and having Win2000 OS
and I notice that when the HFSS using more than 2G, then it will buffer to disk, and making simualtion very slowly.
How to solve this problem?

Go to 64-bit XP.

Yeah, 64bits rock!
When I changed my OS from WinXP to XP64 I had three times the speed with the same hardware.

You should really use a 64bit machine when you simulate structures larger 3GB. I am not sure about HFSS9, but HFSS10 has the 64bit solver included. The usage is the same, simply install xp64 and HFSS. It will automatically use the full power.

HFSS11 has a new solver that seems to be much faster than the MCA from v10. If you are making Metamaterials or related things the version update could help you.

Alternatively, you have the option to reduce your model. Simplify the structures and use symmetry-planes if possible.

I just set up a simulation server with two 2.66GHz Xeon double core processors and 16GB RAM with Win2003Server64 and HFSS11. Hell, thats fast!


why Win2003Server64 instead of XP64?

The server Mainboard Intel S5000PSL does not support XP, but HFSS11 supports Win2003Server.
The board features a memory controller that can map all RAM-Chips to any CPU-core dynamically. So I can run a single simulation with almost 16GB, or one sim with 2GB and one with 12GB, for example.

with 32bit, Windows will limit the amount of RAM that can be accessed by applications to 2GB. You can increase this up to 3GB by changing the boot.ini file. Search google for /3GB switch to see how to do this.

In this case here the problem here is with HFSS. the older version can only handle the problem space to 2GB, i cannot say about HFSS10.

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