cooling |
Research into acceptable |
for the cooling system to handle . In |
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equipment operating temperatures |
practice this calls for improved energy |
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and data centre set points has allowed |
efficiency throughout the electronic |
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the industry to challenge established |
systems . These comprise not only the |
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notions on temperature . It is reckoned |
computer servers , but also the power |
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that energy costs can be reduced by |
distribution infrastructure . The drive to |
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four per cent for every degree increase |
increase server efficiency is already |
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in the set point . Intel found that the |
well entrenched , with techniques |
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effect was not as severe as it expected , |
such as server virtualisation helping |
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when operating temperature was |
to minimise the quantity of servers |
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increased in tests . Intel and several |
that are powered up but underutilised . |
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|
other companies raised their set points from the conventional 68-72 ° F range in order to save cooling costs without significantly impacting on reliability or equipment replacement rates .
Treat the symptom
|
Data centre managers are familiar
with the Power Utilisation Index
as the key metric expressing the
effectiveness of virtualisation .
Power supply advances tackle the cause
|
‘ pizza boxes ’ just a few years ago to
more than 2kW in many of today ’ s
servers , and continuing to increase .
This has two implications for the power
distribution components . The first is that
the increase in server board peak power
demand means that the difference
|
Figure 1 . Functional blocks of a typical distributed power architecture for data centre application . |
||
Allowing a higher operating |
Operators understand that more |
between actual converter efficiency and |
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temperature could be viewed as |
efficient power modules deliver a |
the unachievable perfect 100 per cent |
|||
moving – or , at least , reoptimising – |
higher proportion of the energy |
represents a more significant quantity |
|||
the goalposts . An alternative approach |
purchased from the utility supplier to |
of energy to be dissipated as heat . |
|||
is to treat the symptom by moving to a |
power the servers , while converting |
Keeping this dissipation to a minimum |
|||
location where ambient temperatures |
correspondingly less is converted into |
requires greater operating efficiency . |
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are lower , thereby reducing the |
unwanted heat . This results in an |
The second is the fact that conventional |
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load placed on the cooling system |
initial saving that is magnified by the |
power supplies can only be optimised |
|||
to maintain the target operating |
fact that reducing the heat dissipation |
for a small load range . When outside |
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temperature . Some data centres have |
also lowers the cost of energy |
this range , particularly at lower loads , |
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set up in cooler climates , such as in |
consumed by the cooling system |
the energy efficiency falls further below |
|||
Scandinavia or north-western USA |
needed to remove that waste . |
the maximum . |
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to cut the energy costs associated with cooling their servers . In some of these places , like Norway or |
Energy savings can be achieved
by improving the way power is
delivered to the servers . Figure 1
|
Introducing software defined power |
|||
Sweden in particular , there also often |
shows how the power distribution |
Power supply design has advanced |
|||
happens to be plentiful hydroelectric |
infrastructure typically connected to |
quickly in recent times , with the advent |
|||
or other renewable low carbon |
a data centre server comprises an |
of digital power . Unlike conventional |
|||
energy . Operating in such locations |
AC to DC supply that may power |
analog power supplies whose behaviour |
|||
not only cuts power consumption , by |
an intermediate bus ( DC to DC ) |
is determined by the fixed values |
|||
reducing the effort required from the |
converter connected to the array |
of components such as capacitors |
|||
cooling system to limit the equipment |
of point of load voltage converters |
chosen to ensure stable and predictable |
|||
temperature rise , but also allows |
powering server circuitry at the board |
feedback of the output voltage to power |
|||
further savings if the energy supply |
level . In some systems , the AC to DC |
supply control circuitry , digital power |
|||
situation allows lower utility costs . |
supply may power the point of load |
supply characteristics are determined |
|||
There is a third way . Treating |
converters directly , as shown . |
by firmware . The values of the registers |
|||
any problem at source is usually |
The power demands of server |
that govern the operating parameters |
|||
regarded as the smartest response , |
boards are growing with each |
can be changed more quickly and easily |
|||
and in the context of data centre |
equipment generation , rising from |
compared to using components such |
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cooling this is to generate less heat |
several hundred Watts for server |
as capacitors that have fixed value . |