Specifications
cooling built for reliability
The Panaflo fans used in the rp8400 actually provide demonstrated reliability that is 10 times
better than that of the devices they are cooling (a reliability level that, considering the excellent
reliability history of PA-RISC processors, is extremely impressive). And consider this: To rate fan
life, fan vendors commonly use the “L-10” metric, which is the operating time when there is a 10
percent chance of a fan failure and a 90 percent probability that any given fan will survive. But
HP engineers use a more stringent “L-1” metric; this is the operating time at which there is a 99
percent probability of survival. For the Panaflo fans used in the rp8400, L-1 is over 100,000
hours (11.4 years). And for any rp8400 fan, the probability of successful operation for shorter
times is even greater—over 99.95 percent in the first year of operation.
built-in fan manageability
To further ensure that our customers will experience uninterrupted service through the life of the
product with no data loss or data corruption, HP engineers have implemented sophisticated fan
manageability and protection into the rp8400. Every turbo-cooler fan in this server is actively
monitored and controlled. A fail-safe embedded Smartfan controller is associated with each turbo-
cooler fan, affording active power management in four separate areas. These areas include two
control and two reporting protocols.
Fan control is accomplished in two phases through power metering. First, the controller monitors
fan speed to provide only enough power to meet cooling requirements. In this way, the fan is
never over-taxed and its life is further extended. Second, should a fan begin to slow (an early sign
of fan failure), this controller incrementally increases power to the fan, maintaining cooling
capacity. This sophisticated control extends the fan’s capabilities beyond its specified ratings and
squeezes the maximum useful life from the fan.
fan reporting
For reporting, a set of key indicators enables intelligent monitoring of fan health. Two levels of fan
health are detectable. First, well in advance of failure, the controller detects fan slowing. A
message is passed through system manageability tools to alert IT personnel that this fan should be
replaced at the next scheduled maintenance interval—which can be up to 100 hours later. There’s
no interruption in service.
Second, the embedded processor continues to monitor fan activity through the failing interval, and
it transmits a higher-level message to manageability middleware when this fan slows beyond a
fixed lower limit (generally after more than 100 hours). At that time, system manageability
firmware instructs the operating system to perform a graceful and orderly shutdown. HP’s highest
priority is the protection of data from both loss and corruption, and this graceful shutdown event is
the best way to protect valuable customer data. (We’ve built a significant margin into the selection
of this shutdown threshold so that even unlikely corner cases are protected.)
why turbo-coolers are best for high availability installations
Using turbo-coolers in high availability servers may be a new concept for some customers. Older
fan designs, it is true, often caused single points of failure, where unreliable components caused
system downtime and even data loss. But HP engineers have taken an intelligent approach that
capitalizes on the positive aspects of turbo-coolers, such as improved system density and efficient
component cooling, and they have reduced any issues with reliability and or availability to the
point of insignificance. The turbo-cooler is a natural choice for mission-critical server products such
as the rp8400.
The rp8400’s combination of superior reliability and robust system manageability protocols result
in extremely high-availability cooling. And HP engineers have done extensive testing to ensure this
mission critical availability comes at minimal cost.
crossbar backplane
The second basic rp8400 building block is the crossbar backplane. The crossbar backplane
contains two crossbar chips that provide a non-blocking connection between four cells and their
associated memory and I/O. Also located on the backplane are two PCI bus converter chips that
support core I/O and internal peripherals.
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