HP’s ‘Powerbar’ Blade Server: Benefits and challenges

Adria Ferguson

On Dec. 4, Hewlett-Packard introduced its blade servers, termed
"Powerbar." The servers are based on the open CompactPCI standard used
predominantly in the telecommunications and industrial markets. HP is the first
major vendor to market with a proprietary blade server, since Compaq is running
behind schedule with the release of its QuickBlade server. IBM has been
reselling RLX Technologies’ blade servers but has yet to release its
proprietary blade server (code-named Excalibur). Dell is scheduled to release
its server blades in the first half of 2002, followed by a release of its
"server bricks."

Server blades are essentially compute boards that operate on a common chassis
that enables reduced cabling, power and space requirements (read Defining
Server Blades and Bricks for more information on server blades). Until now,
the server blade companies have been startups, such as RLX Technologies and
Egenera.

Unfortunately, the startups have been facing many challenges – server blade
company FiberCycle recently went out of business and Amphus changed its strategy
from a direct sales model to licensing its IP to second-tier server vendors.
Given the economic slowdown, many companies have reduced their infrastructure
spending and are increasingly being risk averse and choosing well-established
vendors for their long term stability over newly established vendors (even if
the companies are first to market and have better technology).

While Compaq is still developing proprietary technology for its server blades
(which should be introduced within the first half of 2002), HP has shortened its
research and development (R&D) time and extended its potential partnerships
by using the CompactPCI standard for its server blades. HP’s Powerbar servers
will not be available for volume sales until January of 2002. The initial
version will run on Linux (Red Hat, Debian, and SuSE), a Windows version and a
HP-UX (RISC) version should be available in the first half of 2002.

HP’s Powerbar is NEBS compliant, has N + 1 hot swappable power and fans,
top to bottom cooling, front and rear access and can scale to 16 CPU slots, 16
I/O slots, and six networking/management blades per chassis and can be stacked
up to three chassis per rack, allowing for 48 servers per rack (compared to the
traditional 21(2U) to 42 (1U) servers per rack).

The blade design allows for improved cable management by using 15 cables per
two-meter rack compared to almost 200 cables in a traditional server rack. The
server density allows for lower floor space costs, and the reduced power
requirements (50 watts per slot) can decrease power costs.

However, the PCI Industrial Computer Manufacturers Group (PICMG) 2.16
CompactPCI standard has a power and bandwidth limitation of about 50 watts per
board and 1GB per/second. Due to the 50 watt per slot power limitation, HP’s
Powerbar will have performance limitations on a per slot basis. For example, the
initial release uses a Pentium III processor and the PA-RISC based server that
will be introduced in the first half of 2002 will require two slots due to the
additional power requirements. (Which equates to only 24 single CPU RISC-based
servers per (42U) rack, which is less than the 42 servers per rack that
traditional ultra-dense servers can provide and significantly less than the 24
servers in a 3U configuration that RLX Technologies offers.

However, RLX Technologies’ servers rely on Transmeta’s Crusoe chips,
which have ultra-low power requirements but lack error correcting code (ECC)
capabilities.) Additionally, because of the high-power consumption of IA-64
Itanium-based processors, Itanium will most likely not be released in blade form
by HP until at least 2003.

The HP Powerbar solution requires that customers purchase a chassis ($7,525),
CPU blades ($1,925 per blade), I/O blades ($400 per blade) and
networking/management blades ($1,375), which leads to a higher acquisition cost
than traditional entry-level servers, but the delta decreases as clients expand
the system. The benefits are in the form of improved cable management and
reduced power and space costs.

Power and floor space can each cost about 50 percent of the price of the
equipment in three years (i.e., power and space together can cost about the same
price or higher than the acquisition costs).The reduced floor print provided by
the density of the blade servers combined with lower power consumption can often
help reduce floor space and power costs by 25 percent to 50 percent in three
years. However, since the blade servers currently use about the same amount of
floor space as the ultra-dense servers, the majority of savings relative to
ultradense servers would be derived from reduced power costs.

Additionally, the pending HP-Compaq merger adds some uncertainty to the
future of the product line since Compaq will be releasing a blade server of its
own within the next few months. When or if the merger goes through, it is
doubtful that the combined entity will carry both blade product lines – one
product line will most likely have to go. To avoid incurring the higher
acquisition costs and then never realizing the long-term benefits because of
product discontinuance, we recommend enterprises receive support guarantees
particularly for ongoing blade replacement and upgrades for at least five years
after product obsolescence.

Companies are also encouraged to seek guarantees that stipulate should the
vendor discontinue the product line (within 12 to 18 months), the vendor will
provide a replacement product for approximately 100 percent of the value of the
purchase. Blade servers have the potential to ease management and reduce
long-term server costs; however, it is currently a fairly nascent market that
often requires higher acquisition costs than traditional servers and offers
limited interoperability and platform support.