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Stu Maxwell July 23, 2006 20:49

CFX and XP64
Hi all, I have a machine which has 4GB ram and runs a dual core Athlon. I only have a single processor license for CFX (thus, only one core of the processor runs at present), but am looking to add a 2nd processor license to use the 2nd CPU core. Given that XP32 can handle 2GB per processor (forget about the 3GB switch - tried it, XP32 wouldn't go above 2GB), is there any benefit using XP64 with this setup? The problems with XP64 are that it doesn't support iges import with workbench, and there are driver compatability issues with other applications. Thanks!

Joe July 24, 2006 06:48

Re: CFX and XP64
There isnt a xp64 solver executable afaik. Use a linux 64 bit OS.

Bian July 24, 2006 08:11

Re: CFX and XP64

Download CFX-11 Preview for XP64 from customer portal. Official release will be after Oct.

Bian July 24, 2006 08:16

Re: CFX and XP64
XP64 benefit:

1) One solver process can use more than 2GB RAM. 2) A little faster speed has been reported, but not sure. 3) Patitioner can handle much bigger case

So, download XP64 from MS, download CFX11-preview from ANSYS, then get your own feeling.


Glenn Horrocks July 24, 2006 17:36

Re: CFX and XP64
Hi Stu,

In CFX10 there is no real advantage in WinXP 64 bit. If you run it will run in 32 bit mode anyway. CFX11 will fully support WinXP 64 bit in the next release and as Bain said a preview version of it is available from the ANSYS Community Portal.

If you run single processor you will be able to access the full 4GB in 64 bit mode. If you run local parallel in 32 bit you will be able to access 2GB (or close to it) with one process and 2GB (approx) with the other one so can also access 4GB.

You should get a small performance increase by going 64 bit (10% or so is the figure I hear), and I also hear CFX11 is about 20% faster than CFX10. Having said that it is not even at beta state yet so it is strongly recommended not to use this version for serious work. Use it for testing only

The Athlon should scale fairly well in local parallel so providing it is a suitable simulation you should get local parallel speedup factor around 80-90%.

Sounds like your best best is to go local parallel on WinXP 32 bit. Then you will access the full memory, get a healthy speedup and not rely on alpha testing software.

Glenn Horrocks

Stu Maxwell July 24, 2006 18:00

Re: CFX and XP64
Thanks for the replies, guys. I'm not sure if I posed my question correctly, though. My point is, I now have a 4GB RAM machine with a single processor running XP64 - I went for XP64 as I was told it was the only way to access that much RAM with windoze with a single processor lincense. It is able to access all that memory but according to task manager, which shows both CPU cores' usage, only 50% usage max is occurring due to the single processor license (yes, we're on a shoestring here, it's embarrassing enough to have to use windozzzzze). I have found some driver issues with XP64 with other programs and would like to revert to XP32 to solve them. If I do so, and get a 2nd processor license, will XP32 be able to assign 2GB to each processor, so that all 4GB are being used? Basically, is there a benefit from using XP64 (other than a slight speed increase)? I have noticed than on a bare system, XP64 needs alot more RAM to operate itself. I guess dual booting is an option to solve driver issues with other progs, however, as I have built the XP64 system up, I would most likely need to wipe it and install XP32 first (just a guess) with 2 partitions (or a 2nd HDD) then reinstall XP64 - not a very productive way to spend my time! Thanks for any input.


Jeff July 28, 2006 19:48

Re: CFX and XP64 *NM*

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