About memory allocation for Abaqus

[Sbrabra]

Hi all. I want to upgrade my workstation, but I need some information about how different OSs allocate memory, just to avoid useless money efforts... Are the following considetaions correct?

1) Windows 32bit + just one 32or64 bit processor => max memory available for a single process = 2 GBytes.

2) Windows 32bit + N multiple 32or64 bit processors => max memory available for a single process = N*2 GBytes.

4) Windows 64bit + N multiple 64 bit processors => max memory available for a single process = N*4 GBytes.

5) Linux 32or64 bit + any 32or64 bit processors => same considerations written for Windows 32or64 bit.

Is it correct? Thanx for any suggestion!

 

[JOJOMO]

I believe how it works is:

32 bit windows will only allow 2^32 different memory addresses(about 4Gb)

64 bit windows will allow 2^64 different memory addresses (about 1.8E19 bytes or 18exabyte?)

xp requires 2Gb for operating system for both I believe.

You'll be limited by the amount of memory available physically. I don't think there are computers w/ much more than say 8-10 Gb of ram available right now.

Am I wrong anyone?

 

[johnsmith2]

I am sorry, I can't quite understand. If my computer is 8G memory available, XP-64 bit window.

What is the max. memory that I can set up in abaqus job?

 

[JOJOMO]

I would say 6Gb with the memory policy set to "maximum". You may be able to get more out of it though. I've found it to be a trial and error thing.

I'm running large jobs with over 100k elements so I try to get the most memory out of my 64-bit machine (I also have 8 Gb).

I would start w/ say 7 Gb and maximum then slowly back off the memory until it works. Abaqus will abort fairly quick if it cannot allocate the memory requested.

 

[johnsmith2]

My current setting:

Analysis input file processor memory: 1500 MB
ABAQUS/Standard memory cap: 3000 MB
ABAQUS/Standard memory policy: Moderate

But it takes me 48 hrs to complete the analysis:

148106 elements with 836,406 d.o.f.

So, you think I can increase ABAQUS/Standard memory cap to 6000 MB. Let me try.

 

[JOJOMO]

Sure, don't feel bad about 48 hrs for a job. Try over a week for the stuff I do.