Computer configurations for best HFSS performance

I need a powerful computer for complicated HFSS simulations. I wonder if somebody knows what computer configurations can suffice the best performance of HFSS. I mean with what computer configurations I can get the HFSS simulation as fast and good as possible while not waste. Are there some suggestions or ideas?

Thanks in advance.

I would ask Ansys. It would of course depend to a huge amount on the complexity of the model. 8 GB RAM will be fine for many problems, but 800 GB will be insufficient for others. Depending on the license having more than two cores may be no advantage. You can get information about how much RAM and time a simulation uses from the program. I forget what it is, but something like HFSS -> Results -> Profile data.

Dave

what is your HFFSS project ? you know any suggestion from us is related to your project diversity , I have design several Antenna and I used to use this system : 1G byte RAM, Graphic 64M, CPU: 3MHZ Intel and the most time my PC needed was 10 minutes for processing the designs. but as I said I designed easy antenna like Yagi Yoda. so I think if we know what is your project level can guide you better

Thank you.
As the RAM gets larger, the simulations take less time. Is there a limit that only some RAM can be used by HFSS? I mean, if my computer has a larger RAM, the rest will be no use. If so, what's the largest RAM can be used by HFSS? Or how can I know it?

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My project is about closed cavity with complicated incide structure and with 1 or 2 ports for the microwave. I have simulated some, found it need about 7GB RAM. My computer has a RAM of 8GB, so the simulation became quite slowly. In the future we may simulate more complicated structures, so we want to configure a more powerful computer. We want to know if there exists a value of the RAM memory that if the RAM of my computer is larger, the rest of RAM is no use. Then we can consider how to configure the computer to implement the best simulation but with no waste.
Thank you and expect your guidance.

As drkirkby said, the amount of RAM depends of the complexity of your system.
But you should be aware that increasing memory doesn't decrease linearly the computation time.
There are some tricks to reduce the memory needs, like taking advantages of symmetries, splitting the structure into domains, using the FEBI solver...
And BTW, don't forget the processor !

The best advice I can give you is to contact Ansys; you will find some help configuring your hardware setup and maybe some help optimizing your simulations.
Regards

If you are low on memory, so swapping to disk, then adding memory will make a huge difference to the speed, simply because the access speeds of disk and RAM differ considerably.

However, once you have got to the point where you have sufficient RAM, then adding RAM will not decrease the run time.

I'm not aware of any limit on the amount of RAM HFSS will use if the operating system and hardware support it, but you would need to ask Ansys for a definitative answer.

Accoring to http://www.crucial.com/kb/answer.aspx?qid=3743

there's a limit of 192 GB in Windows 7 and Vista.

I know many linux systems which have more than 192 GB RAM. So if you want to access more than 192 GB in a single macinne, it looks like you would need to install the Linux and so the Linux version of HFSS.

I would imagine that if you have a lot of cores in your machine, and an HFSS license that supports it, then you could do use the Optimetrics to analyse multple variations of a model in parallel. I would assume that the amount of RAM needed would grow almost linearly with the number of variations which are simultaneously solved.

Note: On my workstation (a Sun Ultra 27), the machine is supported with a maximum of 12 GB RAM, but the speed the RAM is clocked at is reduced above 6 GB, as the RAM chips are further from the CPU, so can't be accessed as quickly. So the machine might be marginally faster with 6 GB than it is with 12 GB! In fact, I have fitted 24 GB RAM, which is supported by the Intel X3580 Xeon, but not by Sun. But it seems to work OK. (I've never used that machine for HFSS).

Dave

Looking again, it appears the 64-bit Enterprose and Datacentre editions of Windows 2003 server and Windows 2008 server supports 2 TB of RAM, so one is not limited to 192 GB on Windows as I thought.

Oracle sells boxes with Solaris that have 4 TB of RAM in them (SPARC processors), but recent versions of HFSS don't support SPARC. (Older versions did).