On 04/17/2013 04:32 AM, Herbert Fruchtl wrote: > > >>>> "Owned compute" has some advantages over "rented compute." In general, the >>>> control one has over one's owned resources enables applications to run with >>>> greater performance. Some optimizations just demand root access! >>>> >> As someone who has been Scientific Computing/HPC System Admin, I can >> tell you this is a complete myth. > You need at least access to the person with root access. If (s)he's a > colleague > who needs to keep 10 more users in the department happy, you can sit down and > find a solution if your program doesn't work. Fair enough. I agree with that.
> Try to convince Amazon that you > need SHMMAX increased, and that their default processor affinity settings slow > your code down. This is the part I'm not to clear on. I've never worked with AWS, but it's my understanding you do have root access, and actually install the OS yourself on your hosts. are you talking about SHMMAX on the virtual host, as opposed to the guest? To be clear, I'm skeptical about the widespread use of the cloud for HPC, so I'm all for having an in-house cluster and system admins with HPC expertise! Prentice _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
