[Mitgcm-support] RE: AIX/obcs/version questions

[mitgcm-support at dev.mitgcm.org]

Hi James,

 It sounds like it could be a parallelism with OBCS related problem. I
will check with Jake Gebbie who runs in parallel on an IBM with the OBCS
active. As far as I know everything is working for him, but there have
been some issues that he has had to debug.

Chris



> -----Original Message-----
> From: James B. Girton [mailto:jgirton at whoi.edu] 
> Sent: Friday, May 30, 2003 2:00 PM
> To: support at mitgcm.org
> Subject: AIX/obcs/version questions
> 
> 
> Hi, I've got a multi-part question, although there may be a single
> answer...
> I'm encountering problems with some runs on a Boston Univ. 
> parallel machine
> (twister.bu.edu: IBM p690 running AIX 5).
> The configuration has a dense inflow at the top of a N-S slope and a
> radiation boundary condition in the west. Closed walls 
> everywhere else. It
> runs fine on a 4-processor SGI (ceto.whoi.edu) but on the IBM 
> it does funny
> stuff at the boundary (creates dense water where there should 
> be none...at
> first this is confined to the boundary cells only but 
> problems occur later
> when the dense plume gets to the edge and wants to leave). 
> I've made a few
> modifications to the OBC calculation code, but it's the same on both
> machines. I've also tried using the same 16-subgrid 
> decomposition on the
> SGI and that still works. Using advection 77 on both machines.
> Two unresolved issues:
> 1) I'm not entirely sure that the genmake script I'm using is 
> really the
> right thing for this machine. Basically I've just stuck in 
> the AIX case
> Alistair suggested on 5/8/03 and it  mostly seems to work 
> except for this
> OBC thing. Would it be worth fiddling with this some more?
> 2) I'm not exactly sure which version of the code I am using 
> or which one I
> should be using (or even whether it's likely to make a 
> difference). I first
> downloaded to the IBM using "cvs co -d mit -P MITgcm" on May 
> 8. I think it
> was release1_beta1 that has been working on the SGI but I 
> can't get that to
> run on the IBM (although it might just be the older 
> genmake...) I did just
> download release1_p8, which the web page suggests is the 
> newest "official"
> version. I've compiled it (on the IBM) and my initial test 
> still appears to
> give weird behavior at the open boundary.
> ok, this is kind of a mess. Any hints about what to try next? Anything
> obvious come to mind? Why might the same code work 
> differently on the SGI
> vs. IBM?
> 
> cheers,
> james
> 
> 
>