[MITgcm-support] Suggestions for making MITgcm accessible

[Samar Khatiwala]

Hi Jens-Olaf

This is a bit off topic, but just to follow up on your post:

I am currently running the MITgcm on an SX-8 at uni-kiel. This is a  
coarse resolution configuration (128 x 64 x 15).
Unfortunately, performance has not be so great and, I am told by  
other users of the SX, is significantly below its
theoretical peak. Even less than the 25-35% number you quote.

Perhaps you can advise, off-list, on how I can improve things.

Thanks

Samar

On Jun 7, 2007, at 2:28 PM, Jens-Olaf Beismann wrote:

> Dear MITgcm users,
>
>> This "philosphy" works fairly well for most single cpu and  
>> parallel computer architectures, although I am now struggling with  
>> a vector computer for which the MITgcm is only efficient if the  
>> horizontal domain size is fairly large (because the code generally  
>> excludes vectorization in the vertical dimension, and that's not  
>> likely to change).
>
> just a quick comment regarding the use of the MITgcm on vector  
> machines: I'm not familiar with Martin's application, but I know  
> several MITgcm configurations which are used very efficiently on SX  
> machines at other computing centres. These are "medium-sized"  
> regional ocean models, and they typically run at appr. 25-35% of  
> the theoretical peak performance.
>
> As Martin pointed out, it is necessary to have a completely  
> vectorised code to achieve good vector performance, but there is no  
> general problem in running the MITgcm on a vector machine.
>
> Best regards,
>
> Jens-Olaf
> -- 
> Dr. Jens-Olaf Beismann           Benchmarking Analyst
> NEC High Performance Computing Europe GmbH
> Prinzenallee 11, D-40549 Duesseldorf, Germany
> Tel: +49 4326 288859 (office)  +49 160 183 5289 (mobile)
> Fax: +49 4326 288861              http://www.hpce.nec.com
>
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