Server Snapshots: IBM JS21 Blade Server

By Drew Robb (Send Email)
Posted May 14, 2007


The server market is flooded with loads of 1U and 2U blades from all the big hardware vendors. According to analysts, blades are the most dynamically growing area in the server marketplace. The two research heavyweights, IDC and Gartner, place IBM in the leading position in the blade marketplace, with its BladeCenter line of blades garnering a little more than a 40 percent share.

Think all server blades are cut from the same x86 mold? Then you haven't yet seen the BladeCenter JS21, a PowerPC-based blade aimed at the Unix market that can sit alongside an Intel or AMD blade in the same chassis.

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"IBM BladeCenter is the world's most popular blade computing system, with more than 42 percent share of the market according to IDC," says Doug Balog, vice president and business line executive for BladeCenter. "Since its introduction in 2002, IBM has installed more than a half-million BladeCenter systems."

But this is almost all Intel- and AMD-based blades. The IBM JS21, on the other hand, is one of those rare blades that breaks the mold. It uses an IBM POWER processor and is aimed at the Unix market.

"With the JS21, IBM is simply trying to bring more of its server lines into the blade form factor," says Gartner analyst John Enck. "Look for even more such offerings to be introduced over the next few years."

IBM first released this model a year or so ago to replace its first POWER-based blade, the JS20. The initial specs for the JS21 were up to two PowerPC 970 MP processors and up to 16 GB DDR2 SDRAM in 4 DIMM slots. This made it as much as three times faster than its predecessor with twice the memory capacity.

These specs haven't changed much in the interim. Processor choices are now one or two single-core (2.7 GHz, 2x1MB L2 Cache), dual-core (2.3 GHz, 2x1MB L2 Cache) or dual-core (2.5 GHz, 1MB L2 Cache) processors. These frequencies, though, hold only for IBM's newest BladeCenter H high-performance chassis. If the original BladeCenter chassis or the BladeCenter T chassis are used, a small drop in frequency — 0.1 GHz to 0.2 GHz ׫ may be experienced.

On the storage side, this blade has an integrated Serial Attached SCSI (SAS) Controller plus RAID-10 mirroring, and it can hold up to two 2.5 inch 10,000 rpm SAS hard drives for up to 146GB maximum of internal storage. Alternatively, the blade can have one 73 GB drive or no hard drives at all. An integrated Broadcom 5780 controller supports 17X PCI-Express connector and Dual Gigabit Ethernet.

Operating systems supported are AIX 5L (V5.2 and above), Red Hat Enterprise Linux AS 4 for POWER and above, and SUSE Linux Enterprise Server 9 for POWER and above. In addition, the JS21 can take advantage of IBM Advanced POWER Virtualization as an optional feature. This includes support for Virtual LAN POWER Hypervisor, Micro-Partitioning, shared processor pool, Virtual I/O Server, and Integrated Virtualization Manager. As each processing core can be subdivided into as many as 10 virtual servers, a 2-socket dual-core model can have up to 40 partitions.

IBM describes the JS21 as the premier blade solution for 64-bit UNIX, HPC Linux clusters and server consolidation. It is also targeted at WebSphere Web serving, grid, life and earth sciences research, seismic processing and other data-intensive or floating-point, compute-intensive applications.

When it comes to BladeCenter, though, it's really all about the chassis. The JS21 is compatible with the IBM BladeCenter, BladeCenter H and BladeCenter T chassis. The standard BladeCenter 7U chassis has two 2,000 watt power supplies for redundancy and two hot-swappable blowers. It can also hold other blades besides the JS 21. One chassis, in fact, supports up to 14 IBM HS20, JS20, JS21 and LS20 blades, or up to seven HS40 units. Thus, this structure can contain a mixture of Intel Xeon, AMD Opteron and POWER-based blades.

"An integrated solution like IBM BladeCenter can mix architectures and operating systems," says Gordon Haff, an analyst at Illuminata. "For example, one IBM retail customer runs a popular AIX application in its pharmacy department (using a PowerPC-based JS21 blade) — while using x86 blades for all the other retail functions."

With so many different features and options covered above, it's no surprise this IBM product comes in dozens of flavors. At the low end, a system with 2 single-core PowerPC 970 2.70 GHz processors, 2 MB Level 2 cache, 1GB memory and no hard drives is available for $2,499. Higher up the scale, 2 dual-core PowerPC 990 2.50 GHz processors with 4 MB L2 chase, 4 GB memory and one 73 GB hard drive is priced at $4,999. The newer 2.3 GHz JS21 blade option offers ways for some less-demanding shops to shave costs.

Hard Sell

Although IBM has bent over backward in terms of flexibility, Gartner analyst Enck believes the company will have a hard time gaining much sales traction for this box.

"I don't see a lot of clients purchasing these blades," says Enck. "The Unix clients are still more comfortable with the conventional rack and frame form factors."

The JS21 Close Up

Name BladeCenter JS21 The JS21
Vendor IBM
Platform PowerPC
Dimensions 1U Blade: 9.65 inches (245.2 mm) high by 1.14 inches (29 mm) wide by 17.55 inches (445.8 mm) deep; Weight: 9.6 lbs (4.35 kg)
Chassis (BladeCenter H): 15.75 inches (400 mm) high by 17.5 in (444 mm) wide by 28.0 in (711 mm) deep; Weight: 350.0 lbs (159.0 kg)
Processor Details 2-socket single-core or dual-core 64-bit IBM PowerPC 970MP
Hard Drives Up to two SAS drives per blade
Operating Systems AIX, Red Hat Enterprise Linux and SUSE Linux Enterprise Server
Configuration Options Two single-core processors with 1 GB memory and no hard drives; $2,499
Two dual-core processors with 4 GB memory and one 73 GB hard drive; $4,999
Availability Now shipping
Warranty 3 years

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