The 2560 blade nodes JS21 are interconnected through a high speed interconnection network called Myrinet. The different nodes are interconnected via fibre optic cables.
Four of the 44 racks in MareNostrum are dedicated to network elements which allow to interconnect the different nodes connected to the Myrinet network. These four racks are located in the center of the room and each node has a fibre optic cable. The network elements connect the different cables allowing the interconnection from one point to another from the different nodes.
The total Myrinet network is connected through:
- 10 elements Clos256+256
- 2 elements Spine 1280
