IBM BladeCenter delivers speed, power savings

Network World - Optimizing power consumption, CPU performance, and form factor is a never-ending battle in server design and IBM's Bladecenter HS22 succeeds on all counts.

How we tested IBM's Bladecenter HS22

Archive of Network World tests

The HS22 that we tested came with two eight-core Intel 5570 Nehalem processors, two 10Gigabit Ethernet network interface cards, 50GB SSD drives, 150GB 15k hard drives and 48GB of RAM.

Intel claims improved performance and power consumption with their new Nehalem processors, so we tested the HS22 against an IBM HS20 blade with Intel Core-based processors. The Nehalem-based blade delivered a 10x increase in performance, while the amount of energy per transaction was only 12% of the Core-based Xeon processor.

In terms of total overall power consumption, the Nehalem processors consumed 17% more power than the Xeon-based system, but that's a pretty good bargain when you're gaining a 10x boost in performance.

IBM claims that solid state drives (SSD) are desirable because of their increased power efficiency as compared with conventional rotating spindle hard drives. This makes sense because of the SSD's lack of power-consuming moving parts.

We compared the power consumption of the two drive types in the HS22 and found that the SSDs use 5 watts less power at idle than a conventional spindle drive and 5 watts less power under load than a conventional spindle drive.

However, spindle drives are able to sustain 37% more bandwidth with writes than SSDs. This translates to 30% more energy consumed per megabyte written for the SSDs than for the conventional spindles. In other words, spindles are more efficient than SSDs for high I/O rates; SSD drives are a better choice if the drives aren't under heavy load.

Our 10G Ethernet tests showed good network and I/O performance with a peak of 8Gbps and a sustained rate of 7Gbps of HTTP traffic out of the server. The 10Gbps daughter card in our HS22 has two 10G Ethernet ports. The onboard 1G Ethernet ports remain active with the 10G Ethernet card in place.

The 10G Ethernet ports are accessible from the rear of the BladeCenter chassis via a 10G Ethernet switch or a 10G Ethernet pass-through module. The pass-through module allows direct connection to a blade's 10G Ethernet port from outside the chassis. We conducted all our tests with the 10G Ethernet switch in place. The chassis has 10G option slots for a choice of connection methods to the two internal blade 10G ports if installed.

The HS22 makes a great virtualization platform because of the Nehalem processor, which implements Intel's virtualization technology, and for the large RAM capacity. This hardware combination opens the possibility of running many virtual machines on the blade. The number of virtual machines is only limited by the processor and RAM requirements of the VMs.