1. 1 COMPUTER ARCHITECTURE (for Erasmus students) Assoc.Prof. Stasys Maciulevičius Computer Dept. stasys@ecdl.lt stasys.maciulevicius@ktu.lt

2. ©S.Maciulevičius2 2009 Computer power supply Computer power supply is also important for computer their design and operational aspects Every computer power supply has filter: FILTER Converter – stabilizer To monitor220 V AC

3. ©S.Maciulevičius3 2009 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

4. ©S.Maciulevičius4 2009 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 (220- 240V in most of the world) to usable low-voltage DC power for the internal components of the computer

5. ©S.Maciulevičius5 2009 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.

6. ©S.Maciulevičius6 2009 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)

7. ©S.Maciulevičius7 2009 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

8. ©S.Maciulevičius8 2009 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

9. ©S.Maciulevičius9 2009 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

10. ©S.Maciulevičius10 2009 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

11. ©S.Maciulevičius11 2009 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

12. ©S.Maciulevičius12 2009 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 long- term 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

13. ©S.Maciulevičius13 2009 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)

14. ©S.Maciulevičius14 2009 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

15. ©S.Maciulevičius15 2009 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 Power supply problems’ consequences

16. ©S.Maciulevičius16 2009 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

17. ©S.Maciulevičius17 2009 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

18. ©S.Maciulevičius18 2009 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

19. ©S.Maciulevičius19 2009 Stand-By UPS Filter Battery charger Switch Load Power supply Battery  =  =  Inverter

20. ©S.Maciulevičius20 2009 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

21. ©S.Maciulevičius21 2009 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

22. ©S.Maciulevičius22 2009 Line-Interactive UPS Advantages: The optimal price-quality ratio Disadvantages: Not fully protection from network interference

23. ©S.Maciulevičius23 2009 Line-Interactive UPS Load Filter, surge suppressor Battery charger Switch Power supply Battery  =  =  Inverter Automatic voltage regulator

24. ©S.Maciulevičius24 2009 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

25. ©S.Maciulevičius25 2009 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

26. ©S.Maciulevičius26 2009 On-Line UPS Advantages: Full PC protection Disadvantages: High price

27. ©S.Maciulevičius27 2009 On-Line UPS Load BYPASS Switch Power supply Battery  = Inverter =  Battery charger

28. ©S.Maciulevičius28 2009 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

29. ©S.Maciulevičius29 2009 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

30. ©S.Maciulevičius30 2009 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 - 5000- 7000 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

31. ©S.Maciulevičius31 2009 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

32. ©S.Maciulevičius32 2009 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

33. ©S.Maciulevičius33 2009 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

34. ©S.Maciulevičius34 2009 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

35. ©S.Maciulevičius35 2009 Cooling system „Silent Cool“

36. ©S.Maciulevičius36 2009 Cooling system „Silent Cool“ Silent Cool system is essentially a heatsink system, which consists of one main and two additional heatsinks, interconnected by heat- pipes The main heatsink is made of aluminum, but has a copper base Two position of additional copper heatsinks can be changed

37. ©S.Maciulevičius37 2009 Liquid cooling The water cooling alternative with a complete kit provided by Gigabyte Technology – the 3D Galaxy Liquid Cooling System

38. ©S.Maciulevičius38 2009 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

39. ©S.Maciulevičius39 2009 Cryogenic cooling Compressor Evaporator Capillary pipe Processor cooler 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

40. ©S.Maciulevičius40 2009 Cryogenic cooling: VapoChill

41. ©S.Maciulevičius41 2009 Cryogenic cooling: VapoChill The CPU can be cooled to -40 0 C