COMPUTER
ARCHITECTURE
(for Erasmus students)
Assoc.Prof. Stasys Maciulevičius
Computer Dept.
stasys@ecdl.lt
stasys.maciulevicius@ktu.lt
1
Computer power supply
Computer power
supply is also
important for
computer their
design and
operational aspects
 Every computer
power supply has
filter:

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220 V AC
To monitor
FILTER
Converter –
stabilizer
2
Grounding

Plugging the computer into the AC outlet is
necessary to use grounding because it:

prevents a person from being damaged by capacitive
current,

reduces external noise influence on computer work,

reduces the transmission of noise into the power grid

ensure the normal operation of equipment connected to
computer network,

reduces high-frequency electromagnetic radiation
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Computer power supply

A power supply unit (PSU) is the component that
supplies power to the other components in a
computer

More specifically, a power supply unit is typically
designed to convert general-purpose alternating
current (AC) electric power from the mains (220240V in most of the world) to usable low-voltage
DC power for the internal components of the
computer
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Computer power supply
Standard requirements
for power supply:

voltage – 220 V,

tolerance – from
-15% to +10% (i.e.,
from 187 V to 242 V),

frequency - 501 Hz.
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Computer power supply


Typical power ranges are:

from 300 W to 500 W for ordinary home computers

from 450 800 W - for gamers and

from 800 W to 1400 W - for enthusiasts
The highest-end units are up to 2 kW strong and
are intended mainly for servers and extreme
performance computers with multiple processors,
several hard disks and multiple graphics cards (ATI
CrossFire or NVIDIA SLI)
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Computer power supply




Today's standard desktop PC PSU produces the following
DC voltages: +5V, +3.3V, +12V1, +12V2, -12V and a
standby 5V
Additional "point of load" DC-DC converters step down 12V
to the CPU core voltage and other low voltages needed for
motherboard components
All outputs should have a separate current limit to meet
240VA safety requirements of EN 60950
The PSU for high-end discrete graphics cards have an
additional connector to supply extra power to a graphics
card that require more than 75 Watts of total power
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Computer power supply




Power supplies for computers utilize switching mode
technology
Most of today's models are ENERGY STAR® compliant. In
the past it just meant they consumed <10% of rated power
in standby mode
However in active mode the efficiency of cheap computer
power supplies used to be 65-70%
Several years ago was introduced an electric utility-funded
incentive program called 80 PLUS® that requires PC and
server power supplies to demonstrate efficiency >80% at
20% to 100% of rated load and Power Factor >0.9 at rated
load
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Laptop power supply

Most portable computers have power supplies that
provide 25 to 100 watts

In portable computers (such as laptops) there is
usually an external power supply which converts
AC power to one DC voltage (most commonly
19 V), and further DC-DC conversion occurs within
the laptop to supply the various DC voltages
required by the other components of the portable
computer
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Power supply problems

In this age of electricity are two
incontrovertible truths:
 the
first - power network is unable to supply a
stable, high-quality voltage needed for sensitive
electronic equipment
 second
- the user must take care of his
equipment reliability and safety at work
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Power supply problems

Studies have shown that monthly average
of 120 times your computer is exposed to
the power network interference

Effects of power network interference range
from simple crash of operating system and
shortening of electronic devices’ life time,
complete data loss or components’ damage
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Power supply problems

High voltage disturbances (Surges):
 because
of the thunder (duration - up to tens of
ms), switching (length - up to hundreds of ms)
 short-term
(duration - a few periods) or longterm voltage increase over 110% of nominal
value
 short-term
(duration - a few periods, because
of the powerful load connection) or long-term
voltage drop below 85% of the nominal value
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Power supply problems

Voltage disappearance more than a 1 cycle

Radio or pulsed power supply units
interferences

Frequency deviation from nominal value

Form deviation from the sinusoidal
(harmonic distortion)
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Power supply problems



It is therefore very important to ensure reliable
power supplies for computers or (especialy)
servers
Unfortunately, the supply of electricity in the
foreseeable future, certainly not improve the
quality and construction of new power plants and
integrating the network takes a few or even
several years
Therefore, reliable electrical power remains to
take care of themselves
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Power supply problems’
consequences
The unexpected loss of power may damage
the hard drive and all of its data may be lost
 In the best case will be lost information
contained in the cache, in the worst - can be
damaged disk file allocation table (FAT)
structure and data on the disk
 This example - only an assumption, nothing
indicates that this may happen (or not
happen) with you

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Uninterruptible Power Supply
An Uninterruptible Power Supply (UPS)
takes its power from two or more sources
simultaneously
 It is usually powered directly from the AC
mains, while simultaneously charging a
storage battery
 Should there be a dropout or failure of the
mains, the battery instantly takes over so
that the load never experiences an
interruption

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UPS
 There
are several types of these
devices
 According to the principle of operation
uninterruptible power supplies are
divided into the following main
categories:
 Stand-By,
 Line-Interactive
and
 On-Line
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Stand-By UPS




The stand-by UPS (sometimes also called offline
UPS) is the simplest and least expensive UPS
design
In this type of UPS, the primary power source is line
power from the utility, and the secondary power
source is the battery
It is called a stand-by UPS because the battery and
inverter are normally not supplying power to the
equipment
The battery charger is using line power to charge the
battery, and the battery and inverter are waiting "on
standby" until they are needed
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Stand-By UPS
Power
supply
Switch
Filter
Battery
charger
=
Load
Inverter
Battery
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Stand-By UPS
 Advantages:
Low price
 Disadvantages:
 In
order to reduce the price of the UPS
devices, not all models produce sinusoidal
output voltage
 Not fully protection from network
interference
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Line-Interactive UPS



In this type of unit, the separate battery charger,
inverter and source selection switch have all been
replaced by a combination inverter/converter, which
both charges the battery and converts its energy to
AC for the output as required
AC line power is still the primary power source, and
the battery is the secondary
When the line power is operating, the
inverter/converter charges the battery; when the
power fails, it operates in reverse
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Line-Interactive UPS
 Advantages: The optimal price-quality
ratio
 Disadvantages:
Not fully protection
from network interference
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Line-Interactive UPS
Power
supply
Filter, surge
suppressor
Battery
charger
Automatic
voltage
regulator
=
Switch
Load
Inverter
Battery
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Example - APC UPS


Smart-UPS series devices (from АРС company)
have a capacity 420 VA, 650 VA, 1000 VA, 1400
VA, 2200 VA, 3000 VA, 5000 VA
Battery-powered run time:





420 Series - 4 minutes at 100% load and 10 minutes at
50% load
650 Series - 5 minutes at 100% load, 14 minutes at 50%
load
1000 Series - 5.5 minutes at 100% load, 14 minutes at
50% load
1400 Series - 7 minutes at 100% load, 19 minutes at 50%
load
At 176-282 V battery is not used
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On-Line UPS




The online UPS, sometimes called a true UPS, is
the best type you can buy
Paradoxically, it is both very similar to, and totally
opposite to, the least-expensive type, the standby
UPS
It is very similar to it in that it has the same two
power sources, and a transfer switch that selects
between them
It is the exact opposite from the standby UPS
because it has reversed its sources: in the online
UPS the primary power source is the UPS's battery,
and utility power is the secondary power source
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On-Line UPS
 Advantages: Full PC protection
 Disadvantages:High price
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On-Line UPS
Battery
charger
Power
supply
BYPASS
Inverter
 =
= 
Switch
Load
Battery
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Main UPS parameters





Output power (measured in volt-amps) - it must be higher
than the consumption of computer devices. It should also be
assessed at the maximum value
Output voltage form. Ideally - Sine. The best models have
harmonic coefficient less than 3%
Switching threshold - the voltage level, when UPS switches
to reserve power (battery)
Switching time - the duration of the switch to reserve power.
Typically equals 1-10 ms. It affects the stability of the
connected hardware
Battery working hours - depends on battery capacity,
charge level, load
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Cooling



Just a few years ago it was enough to cool a
processor by aluminum cooler, rotating at 2500
rpm.
However, with the emergence of powerful
processors and video accelerators, a number of
companies (for example, "Titan," Thermaltake")
launched a high-quality coolers made of different
metals, in particular – copper
Cooler is a radiator, mounted on the CPU (video
card chips etc.), plus a fan
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Cooling - fan




The main criteria for selection of the fan - the
number of revolutions per minute. The faster it turns,
the better aeration, but an increase in noise level too
Silent fans turn 3000-4500 rpm. Noisier fans - 50007000 rpm.
Radiator is important, too. It is attached to a chip,
which emitted heat must be absorbed and dissipated
into the air
The larger radiator surface, the more effective it
dissipates heat, so to increase the surface
manufacturers use vertical or obliquely tilted plates
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Foxconn CMI-775-1S






For Intel Pentium 4
LGA775 2,8-3,2GHz and
Intel Celeron D LGA775
Made of aluminium
Fun rotates at 2000 rpm
Weigth – 550 g.
Noise – 20 db
Foxconn CMI-775-4B is
made of aluminium, but has
cooper core
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Modern CPU cooler
Low-noise 120mm Blue LED
Zalman CPU cooler that has
powerful cooling
performance
CPU supported:
Pentium 4, Celeron D, Pentium D,
Core 2 Duo, Core 2 Quad, Core 2
Extreme, Pentium Dual Core, Core
i7, Core i5, Sempron, Athlon,
Athlon 64, Athlon FX, Athlon 64 FX,
Opteron, Dual-Core Opteron,
Phenom, Athlon X2, Athlon 64 X2,
Phenom II, Athlon II
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Silent CPU cooling





The quiet CPU coolers are made from more
expensive, but much more conductive copper
Copper is nearly twice as efficient at conducting
heat than aluminum
An important component of superior computer
cooling is the use of high quality thermal compound
when attaching heatsinks
Keeping computer free of dust contributes to
computer cooling
Air filters over the case front/rear airflow vents can
slow down airflow into and out of your case, thus
reducing computer cooling
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Cooling system „Silent Cool“
Asus company announced a passive cooling
system “Silent Cool” for graphic cards
 Company representatives claim that their
system set up will be much more effective
than similar decisions by other companies
 It uses passive cooling - such computer
cooling mode, when the fans are not used.
Their lack of substantially reducing the noise
in PC

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Cooling system „Silent Cool“
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Cooling system „Silent Cool“
Silent Cool system is essentially a heatsink
system, which consists of one main and two
additional heatsinks, interconnected by heatpipes
 The main heatsink is made of aluminum, but
has a copper base
 Two position of additional copper heatsinks
can be changed

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Liquid cooling

The water cooling
alternative with a
complete kit provided
by Gigabyte Technology
– the 3D Galaxy Liquid
Cooling System
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3D Galaxy Liquid Cooling System

Specifications:
 Waterblock:
68 x 92 x 30 mm / Copper base
with acrylic cover
 Pump: 61 x 60 x 46 mm / 400 Liters per hour
@ 20db
 Radiator: 125 x 197 x 64mm / Aluminum /
120mm fan with 3-pin header
 Reservoir: 75 x 75 x 92 mm / 300 cc capacity
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Cryogenic cooling
Classical household
refrigerator scheme: the
compressor pumps
liquefied gas (Freon or its
substitute), in capillary net
it intense evaporats and
freezes chamber.
The same compressor
sucks gas from the
freezing chamber and
compress them making
liquid
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Evaporator
Capillary
pipe
Compressor
Processor
cooler
39
Cryogenic cooling: VapoChill
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Cryogenic cooling: VapoChill
The CPU can
be cooled to
-400 C
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