User guide
Chapter 2. InfiniBand products for BladeCenter 25
2.6.2 InfiniBand DDR HCAs
Three recently added 4X DDR HCAs are also available, resulting from a partnership between
IBM and Mellanox. Software differentiates the three offerings, in that they use a common
CFFh base HCA, and then depending on what part number are ordered, will come with
support for different software.
These HCAs require that the InfiniBand Pass-thru Module (or other supported InfiniBand
switch module) are installed in bay 7 or bay 9 of the BladeCenter H chassis, or both bays 7
and 9 for redundancy.
The details on these options are as follows:
4X InfiniBand DDR Expansion Card (43W4423)
For this HCA the user must independently obtain drivers. This will initially offer limited
support from IBM, with OFED support being available from the OFED web site
Cisco 4X InfiniBand DDR Expansion Card (43W4421)
This version of the HCA will come with software and support from Cisco, and comes with a
license to use the Cisco OFED stack. The software is based on the OFED stack with
enhancements and improved support to interface with Cisco switches and gateway
products. In the future, Cisco plans to also support their Commercial stack for this HCA
Voltaire 4X InfiniBand DDR Expansion Card (43W4420)
This version of the HCA will come with software and support from Voltaire, and comes
with a license to use the Voltaire GridStack product. The software is also based on the
OFED stack with enhancements and improved support to interface with Voltaire switches
Key features include:
1.2µs MPI ping latency
Two 4x DDR capable (20 Gbps) InfiniBand ports; support auto-negotiation to SDR
CPU offload of transport operations
End-to-end QoS and congestion control
Hardware-based I/O virtualization
TCP/UDP/IP stateless offload
Based on Mellanox's new ConnectX InfiniBand to PCI-express bridge chip
Supports the OpenFabrics Enterprise Distribution (OFED) drivers and protocol support
Support for Cisco's and Voltaire's drivers stacks
Additional options include:
InfiniBand 3m DDR Cable (43W6742)
InfiniBand 8m DDR Cable (43W7243)
2.6.3 Compatibility with other InfiniBand options for BladeCenter
Initially the DDR expansion cards are supported only with the InfiniBand Pass-thru Module.
Similarly, initially, the InfiniBand Pass-thru Module is supported only when connected to DDR
Note: The QLogic Bridge modules are not compatible with the pass-thru module, because
there is no connectivity from the module to the bridge slots. Also, unlike other InfiniBand
switch modules for the BladeCenter, if InfiniBand communications are desired between
blade servers in the same chassis, some sort of external InfiniBand connectivity must be
provided.