
IBM BladeCenter

The IBM BladeCenter was IBM's blade server architecture, until it was replaced by Flex System in 2012. The x86 division was later sold to Lenovo in 2014. 
History.
Introduced in 2002, based on engineering work started in 1999, the IBM eServer BladeCenter was relatively late to the blade server market. It differed from prior offerings in that it offered a range of x86 Intel server processors and input/output (I/O) options. 
The naming was changed to IBM BladeCenter in 2005. In February 2006, IBM introduced the BladeCenter H with switch capabilities for 10 Gigabit Ethernet and InfiniBand 4X.
A web site called Blade.org was available for the blade computing community through about 2009.
In 2012 the replacement Flex System was introduced.
Enclosures.
IBM BladeCenter (E).
The original IBM BladeCenter was later marketed as BladeCenter E. Power supplies have been upgraded through the life of the chassis from the original 1200 to 1400, 1800, 2000 and 2320 watt.
The BladeCenter (E) was co-developed by IBM and Intel and included:
IBM BladeCenter T.
BladeCenter T is the telecommunications company version of the original BladeCenter, available with either AC or DC (48 V) power. Has 8 blade slots in 8U, but uses the same switches and blades as the regular BladeCenter E. To keep NEBS Level 3 / ETSI compliant special Network Equipment-Building System (NEBS) compliant blades are available.
IBM BladeCenter H.
Upgraded BladeCenter design with high-speed fabric options, announced in 2006. Backwards compatible with older BladeCenter switches and blades. Features:
IBM BladeCenter HT.
BladeCenter HT is the telecommunications company version of the BladeCenter H, available with either AC or DC (48 V) power. Has 12 blade slots in 12U, but uses the same switches and blades as the regular BladeCenter H. But to keep NEBS Level 3 / ETSI compliant special NEBS compliant blades are available.
IBM BladeCenter S.
Targets mid-sized customers by offering storage inside the BladeCenter chassis, so no separate external storage needs to be purchased. It can also use 110 V power in the North American market, so it can be used outside the datacenter. When running at 120 V , the total chassis capacity is reduced. Features:
Intel based.
Modules based on x86 processors from Intel.
HS12.
(2008) Features:
HS20.
(2002–6) Features:
HS21.
(2007–8) This model can use the High-speed IO option of the BladeCenter H, but is backwards compatible with the regular BladeCenter. Features:
HS21 XM.
(2007–8) This model can use the High-speed IO option of the BladeCenter H, but is backwards compatible with the regular BladeCenter. Features:
HS22.
(2009–11) Features:
HS22v.
(2010–11) Features are very similar to HS22 but:
HS23.
(2012) Features:
HS23E.
(2012) Features:
HS40.
(2004) Features:
HC10.
(2008) This blade model is targeted to the workstation market, Features:
HX5.
(2010–11) This blade model is targeted at the server virtualization market. Features:
AMD based.
Modules based on x86 processors from AMD.
LS20.
(2005-6) Features:
LS21.
(2006) This model can use the high-speed I/O of the BladeCenter H, but is also backwards compatible with the regular BladeCenter. Features:
LS22.
(2008) Upgraded model of LS21. Features:
LS41.
(2006–7) This model can use the High-speed IO option of the BladeCenter H, but is backwards compatible with the regular BladeCenter. Features:
LS42.
(2008–9) Upgraded model of LS41. Features:
Power based.
Modules based on PowerPC- or Power ISA-based processors from IBM.
JS20.
(2006) Features:
JS21.
(2006) This model can have the High-speed IO option of the BladeCenter H, but is backwards compatible with the regular BladeCenter. Features:
JS22.
(2009) Features:
JS23.
(2009) Features:
JS43 Express.
Features:
JS12 Express.
Features:
PS700.
Branded as part of IBM Power Systems. Features:
PS701.
Features are very similar to PS700, but
PS702.
Think two PS701 tied together back-to-back, forming a double-wide blade
PS703.
Features are very similar to PS701, but
PS704.
Think two PS703 tied together back-to-back, forming a double-wide blade.
Cell based.
Modules based on Cell processors from IBM.
QS20.
Features:
QS21.
Features:
QS22.
Features:
UltraSPARC based: 2BC.
Themis computer announced a blade around 2008.
It ran the Sun Solaris operating system from Sun Microsystems.
Each module had one UltraSPARC T2 with 64 threads at 1.2  GHz and up to 32 GB of DDR2 SDRAM processor memory.
Advanced network: PN41.
Developed in conjunction with CloudShield, features: 
Modules.
Switch modules.
The BladeCenter can have a total of four switch modules, but two of the switch module bays can take only an Ethernet switch or Ethernet pass-though. To use the other switch module bays, a daughtercard needs to be installed on each blade that needs it, to provide the required SAN, Ethernet, InfiniBand or Myrinet function. Mixing of different type daughtercards in the same BladeCenter chassis is not allowed.
Gigabit Ethernet.
Gigabit Ethernet switch modules were produced by IBM, Nortel, and Cisco Systems.
BLADE Network Technologies produced some switches, and later was purchased by IBM.
In all cases speed internal to the BladeCenter, between the blades, is non-blocking. External Gigabit Ethernet ports vary from four to six and can be either copper or optical fiber.
Storage Area Network.
A variety of SAN switch modules have been produced by QLogic, Cisco, McData (acquired by Brocade) and Brocade ranging in speeds of 1, 2, 4 and 8 Gbit Fibre Channel. Speed from the SAN switch to the blade is determined by the lowest-common-denominator between the blade HBA daughtercard and the SAN switch. External port counts vary from two to six, depending on the switch module.
InfiniBand.
A InfiniBand switch module has been produced by Cisco. Speed from the blade InfiniBand daughtercard to the switch is limited to IB 1X (2.5 Gbit). Externally the switch has one IB 4X and one IB 12X port. The IB 12X port can be split to three IB 4X ports, giving a total of four IB 4X ports and a total theoretical external bandwidth of 40 Gbit.
Pass-through.
Two kinds of pass-through module are available: copper pass-through and fibre pass-through. The copper pass-through can be used only with Ethernet, while the Fibre pass-through can be used for Ethernet, SAN or Myrinet.
Bridge.
Bridge modules are only compatible with BladeCenter H and BladeCenter HT. They function like Ethernet or SAN switches and bridge the traffic to InfiniBand. The advantage is that from the Operating System on the blade everything seems normal (regular Ethernet or SAN connectivity), but inside the BladeCenter everything gets routed over the InfiniBand.
High-speed switch modules.
High-speed switch modules are compatible only with the BladeCenter H and BladeCenter HT. A blade that needs the function must have a high-speed daughtercard installed. Different high-speed daughtercards cannot be mixed in the same BladeCenter chassis.
10 Gigabit Ethernet.
A 10 Gigabit Ethernet switch module was available from BLADE Network Technologies. This allowed 10 Gbit/s connection to each blade, and to outside the BladeCenter.
InfiniBand 4X.
There are several InfiniBand options:
Roadrunner TriBlade (custom module).
The IBM Roadrunner supercomputer used a custom module called the TriBlade from 2008 through 2013. An expansion blade connects two QS22 modules with 8 GB RAM each via 4 PCIe x8 links to a LS21 module with 16 GB RAM, two links for each QS22. It also provides outside connectivity via an Infiniband 4x DDR adapter. This makes a total width of four slots for a single TriBlade. Three TriBlades fit into one BladeCenter H chassis.