DCN January 2017 | Page 28

cooling
Digital power has brought
hence offer more , faster , and better
represents the current state-of-the-
economies of scale for power supply
services for end users .
art , and software defined power
vendors , who can create platform
Digital power has been
is ready to unlock even more of
power supplies that can be configured
enthusiastically adopted across
the advantages of flexible , digital
for multiple applications or to suit
telecom markets and networking and
configurability .
individual end user requirements or a
data centre equipment . The flexibility
Software defined power is at the
variety of operating conditions . In a
of digital power allows the modules to
beginning of its development curve ,
data centre application , for example ,
be configured for optimum efficiency
and rapid improvements in application
a digital power supply can be
under a variety of operating conditions .
code are likely . Server OEMs can be
programmed with one set of values to
Power supply design is in the
expected to issue frequent power
maximise efficiency at or close to full
process of an even more exciting
application software updates early in
load , with the flexibility to change to
transition , building on the advantages
the lifecycle of deployed products ,
low load settings in order to maintain
of digital power and introducing real
which could be applied remotely
high efficiency . This contrasts with
time adaptability managed by an
and therefore transparently as far as
the efficiency of an analog supply ,
application running in software on
users are concerned : the only visible
which would be significantly reduced
the central controller . This evolution ,
effect being lower demand on the
at lower load .
known as software defined power
cooling systems and a corresponding
The digital power modules
architecture ( SDPA ), brings even
reduction in the utility bill .
are usually adjusted by a central controller , which communicates
greater flexibility and opportunity to fine
tune the power supply automatically
Summary
with module registers over a
in response to changes in load or
Data centre operators who are
Power Management Bus ( PMBus )
to accommodate slower variations
concerned about reducing their utility
connection as illustrated in Figure 2 .
such as the effects of component
costs can take a number of actions ,
PMBus is an industry standard
aging . Software defined power ,
including finding cheaper sources of
developed from the System-
and particularly the design of SDPA
energy where possible , combined
Management Bus ( SMBus )
applications , is at the beginning of
with various techniques to reduce the
specification , and defines a physical
a development curve that will drive
burden on cooling systems . These
connection and protocol for
significant increases in performance
include raising the restrictions on
exchanging data between power
and efficiency while also sharpening
acceptable operating temperatures ,
modules . In addition , digital power
responses and enabling greater power
where this is possible without impairing
Figure 2 . Digital power modules controlled by instructions delivered across PMBus connection .
supplies can be stabilised using fewer on board capacitors , which enables smaller power modules thereby liberating extra board real estate to host greater processing power and
density resulting in a further reduction
in module dimensions and demand for
board real estate .
Implications for data centre operators
reliability , and in some cases locating facilities in geographical locations where lower ambient temperatures effectively provide free cooling . More recently , configurable digital power modules have emerged bringing the
As far as data centre owners and
potential for greater efficiency and
operators are concerned , the power
reduced energy cooling costs .
supply strategies and on board
As digital power leads naturally
componentry is largely unseen .
to software defined power , higher
However , gaining some insight into
efficiency can be maintained across
the subsystems distributing power to
a wider set of operating conditions .
the hardworking computer servers
New server equipment featuring
can help understand how design
software defined power can help to
improvements here can contribute
reduce utility bills immediately , and is
to better overall efficiency and
likely to deliver further savings in the
also enable increased compute
future as the technology continues to
performance . Digital power
mature .
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