[Users] BenchIO_HDF5 questions

[Avi Purkayastha]

Thomas,

>> 2) Is there an order of preference based on importance, for these   
>> three
>> tests -- onefile, eachproc, and 8proc from the Cactus user   
>> community,
>> or all of equal importance?
>
> Nowadays we almost always output in parallel on each processor because
> it gives the best performance.

I understand from the message that yours and the communities choice  
for 'eachproc' is due to lack of fast disks in combination with  
parallel f/s not delivering the performance that you are getting from  
'eachproc'. But in the future if the other choices did deliver  
comparable performance in terms of throughput would that be  
preferable from the algorithmic and implementation standpoint?

>
> I don't have any results for these benchmarks. You could take a  
> look at
> the disk I/O scaling tests we have performed on our AEI clusters when
> they were delivered. They don't use Cactus but mimic Cactus behaviour
> during a parallel checkpoint.

I looked at www.cactuscode.org but did not find anything there. Maybe  
you can point me to where that data might be?

Thanks

	-- Avi