64-bit vs 32-bit THA output

[StuartRogers]

Hi,

I am running a time-history analysis of a large model. I have been running a number of different time-history inputs. To help to speed things up, I asked collegues to run some of the analyses for me.

Having unintentionally run the same analysis on a 32-bit and a 64-bit machine (both running ROBOT 2011). I noticed that we get slightly different time-hirstory outputs. This results in different secondary response spectra being produced between the two models.

The models are identical (same number of elements, loading, time step etc). The only difference is that one was run on the 64bit version and one was run on the 32-bit version.

Do the 32-bit and 64-bit versions use different precision? Are there other reasons why I would be seeing this descrepency in the time-history outputs between the two versions?

Thank you for your help.

Regards,

Stuart

[jad.dellel]

Hi,

Do the 32-bit and 64-bit versions use different precision?

No, you shouldn't have any differences, both of version use the same kernel.

Are there other reasons why I would be seeing this descrepency in the time-history outputs between the two versions?

Please, check the version of both, you should have 24.0.6 (see below)

[StuartRogers]

Jad,

Thank you for your reply.

You are correct. The results when run with 24.0.6.3598 and 24.0.6.3598 (x64) are the same. Are these the latest version of ROBOT? If not, would we expect significant differences, if the THA was run with the latest version?

One of my collegues was running version 24.0.0.3481.

Also, a number of runs were done by a collegue who has now left and his computer is no longer available. Is it possible to find out the version of ROBOT that was used to run the analysis? (I have the .rtd and .RT_ files).

Is there an update announcement facitily which will allow us to judge whether future updates may significantly change the results?

Thank you for your help.

Regards,

Stuart

[Artur.Kosakowski · Accepted solution]

You are correct. The results when run with 24.0.6.3598 and 24.0.6.3598 (x64) are the same. Are these the latest version of ROBOT?

SP6 is the last Service Pack for Robot 2011 however the last version of Robot is 2013.

Is it possible to find out the version of ROBOT that was used to run the analysis? (I have the .rtd and .RT_ files).

If you move your mouse over a rtd file you can see the version number in the displayed box. The last number indicates the SP number.

26 = 2013

25 = 2012

24 = 2011 ...

Is there an update announcement facitily which will allow us to judge whether future updates may significantly change the results?

The description of the corrections can be found in the readme file that is available for each SP.

http://usa.autodesk.com/adsk/servlet/ps/dl/index?siteID=123112&id=2334435&linkID=13140816

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