Energy Efficient Computing Flashcards
Today, what does the processing world consist of?
Today, the processor world increasingly consists of the red (those high SPEC marks/watt) and the dead (those without).
What is the energy problem?
∙ our sources of energy are steadily decreasing, whilst our demand for energy is steadily increasing;
∙ the emission of greenhouse gases is now seem by most climatologists as being linked to global warming.
What is the best and worst case rise of electricity demand by 2030?
Electricity demand for ICT might rise to 8% of total electricity demand by 2030, in the best case, or 21% in the worst case.
What is the challenge of energy-efficient operation?
The challenge of energy-efficient operation is to achieve
computation rates subject to power dissipation constraints.
What is ACPI?
The Advanced Configuration and Power Interface (ACPI):
∙ defines per-system power states S0-S6;
∙ defines per-device power states D0-D3;
∙ defines per-device performance states P0-P15.
The S0, D0 and P0 states have normal power consumption;
others have successively lower power consumption.
How could a fan save power?
A fan could only spin when required (i.e. when PC is too hot) and only as fast as is necessary
How could a disk save power?
Switching off when not in use Defragmenting it (promoting reads delaying writes)
How could a processor save power?
Shut down the cores (turn off some functional units)
Lower the clock rate.
What is the problem with on-premises data centres?
On-premises data centres may have upto 25% unused
“zombie” servers that no one dare retire.
What is the problem with traditional cloud data centres?
Traditional cloud data centres using off-the-shelf components have a Power Usage Efficiency (PUE) of 2.0, far from a perfect 1.0.
What is a Hyperscale Cloud Data Centres?
Hyperscale cloud data centres using Open Compute Project components have a Power Usage Efficiency (PUE) of 1.2, close to a perfect 1.0. One Open Compute Project server replaces 3.75 traditional ones.
3 ways to lower power usage efficiency?
1 bespoke hardware;
2 smarter cooling;
3 mobile computing.
How does bespoke hardware lower the PUE number?
One way to lower the power usage efficiency number is by building bespoke hardware, stripping out video cards, USB connectors, blue lights, fixing screws.
How does smarter cooling lower the PUE number?
Another way to lower the power usage efficiency number is by smarter cooling, by location or by technology.
How does mobile computing lower the PUE number?
Another way to lower the power usage efficiency number is by letting mobile computing take on the work of larger devices (but worry about Netflix and high-definition camera phones)
