On Nov 7, 2011, at 12:44 PM, Robert Horton wrote: > Hi, > > Most of what I know about Infiniband came from the notes at > http://www.hpcadvisorycouncil.com/events/switzerland_workshop/ > agenda.php > (or John Hearns in his previous life!). > > On Mon, 2011-11-07 at 00:01 +0100, Vincent Diepeveen wrote: >> Do i need to connect both to the same switch? >> So in short with infiniband you lose 2 ports of the switch to 1 >> card, is that correct? > > You probably want to just connect one port to a switch and leave the > other one unconnected to start with.
What's the second one doing, is this just in case the switch fails, a kind of 'backup' port? In my naivity i had thought that both ports together formed the bidirectional link to the switch. So i thought that 1 port was for 10 gigabit upstream and the other port was for 10 gigabit downstream, did i misunderstood that? > >> CARDS: >> Do all switches work with all cards? >> Can you mix the many different cards that are out there of 4x >> infiniband? >> If not, can you mix from mellanox the different cards theirs? So mix >> from 1 manufacturer cards? > > They will (or at least should) all work to a point but depending on > what > combination you are using you may not get some features. If you > want an > easy life keep it all from the same manufacturer I will load the switch (es) to the maximum number of messages a second it can handle, > >> Does infiniband 4x work for x64 machines? > > The 4x bit is the number of links aggregated together. 4x is normal > for > connections from a switch to a node, higher numbers are sometimes used > for inter-switch links. You also need to note the data rate (eg SDR, > DDR, QDR etc). > >> DRIVERS: >> Drivers for cards now. Are those all open source, or does it require >> payment? Is the source released of >> all those cards drivers, and do they integrate into linux? > > You should get everything you need from the Linux kernel and / or > OFED. > >> MPI: >> The MPI library you can use with each card is that different >> manufacturer from manufacturer? Free to download >> and can work with different distro's? Does it compile? Is it just a >> library or a modified compiler? > > There are quite a lot to choose from but OpenMPI is probably a good > starting point. > > Hope that's some help... > > Rob > _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
