*img.photobucket.com/albums/v449/ROSHANASHRAF/untitled-6.jpg
Scaring the woolies out of people with this pic. So I thought I would make it more dramatic and scary using my silly little paint skills and my camera.
Nothing great, but its a shame to run those fine hardware on a stupid psu. Issued in public interest.
Alternate Link to this pic if you cant see it:
*www.imgx.org/pfiles/8081/untitled.JPG
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What is a power supply?
In a nutshell, power supply converts AC into DC and distributes power to the power according to the pc's needs. There are 2 types of psu- the first is irrelevant and non feasible for a pc- even for an enthusiast. Second one is the one we use-switching mode power supplies AKA SMPS. I'll try to keep this advice as "non- technical" as possible, but if you cant understand, please make efforts to google it.
Before we continue let me clarify 2 things-
#1. just because a power is a 700 watt based psu which gives a 60 amps- doesnt mean it will consume all of it- If a pc requires less, it will take less or else more. If you buy an overpower psu and your system utilises 1/4 part of its potential, its a waste. As a good friend of mine told- the system should use atleast 75% of the power supplies' potential.
#2. Just because full form of smps is switching mode power supplies- doesnt mean there's a switch behind. If you want to know what do they mean by switching, make some efforts and google for it.
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What should you expect from this guide?
I will not use any formulas and I will try to prevent any technical jargon as much as possible- but for God's sake make efforts to use google. Even I have a book knowledge. "Wattage = Voltage * Amperage" is something which even a 6th standard school boy knows. We are living in a section of the society run by economics. Very few manufacturers actually tell the truth on the specs on the side panel. Book knowledge is accessible by many, but street smart is something that is is acquired. This is just a guide but a ball in your court. Some people ask me via PM with great fascination about power supply, while there are certain individuals questioning something which is fact. Knowledge is meant to be spread- that is why I am being in number of forums I try to help what I can- but at the end of the day nothing beats research. Besides the ball is in your court- your money your wish.
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Why think about power supply now?
More systems becomes sophisticated but it will need a proper supply for pc's long term health. In reality- psu is responsible for more than half of the pc hardware problem. After the days of AMD 64 athlon, power supply is the vital part of the system. Till those days, l&c, VIP, ZEBRONICS, intex and some el cheapos like odessey. In those days, zebronics and l&c (now VIP) WERE good power supplies. Then came cm extreme 500w and the way we look at power supplies has changed a bit.
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What are the problems from using underpowered power supply/el cheapo power supply?
Anything. A low-quality power supply can cause several problems, which are mostly difficult to be solved. A defective or bad-intentioned power supply can lock the PC, can result in hard disk bad sectors, can result blue screen of death errors and random resets and freezings, added to many other problems. There have been cases that spikes have fried southbridge, northbridge and even onboard graphic and sound chips. Hard drive and ram are usually the first victims. People eventually spend 1000-5000 (depending on their system) to get it working. But in reality it works barely but its a damaged wreck. Prevention is better than cure, dont you think?
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How do you judge a power supply?
Not by watts- change that mentality if you have that. There have been cases that unethical dealers and even idiotic people give away the ones which bundle with silly cases. When you talk about these so called high performance power supply- they say its over exaggerated. Its a fact that dealers will try to sell away things which they have in stock and people have a bad habit of buying anything cheap. They need to learn some new set of words- VALUE FOR MONEY. People with half knowledge of computers claim that an average 800 watt can topple a "high performance" power supply with a rating of 400w. Tell them to wake up and smell the coffee- using half the knowledge is more dangerous than no knowledge at all. Power supply manufacturers over exaggerate- its a marketing gimmick. Most probably it pulls 800w from the socket but it will definatly give theoratical supply of 390w to the pc.
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Why would an el cheapo rated 800w give only 390w? Where are the rest going to? How do I judge a power supply?
There's something very important called efficiency. Higher the efficiency, lesser the power wasted. As I said before (if you read properly) power supply converts AC into DC. If you want to know what is AC and DC power- make efforts to google. When AC gets converted to DC- heat is produced. Major chunk of power is wasted on this heat. Its a reality that there wont be 100% power conversion for a feasible smps unless something ground breaking is invented. Quality of the pcb circuit board, quality and thickness of cabling, cooling, capacitors and other electric components with a good casing assures proper efficiency. Companies makes big promises but its an inevitable process that a well known pc enthusiast, reviewer and in some cases ethical and knowledgeable dealers will give you proper advice.
In order to get a good enough power supply, you need to make efforts to google and use some common sense. Over the years have passed and the importance of +12v rails have come out. Its always necessary that you proper amps for your system. There An average system can survive with 19 amps on +12v rails.
Oh yeah this is also another very important point that many so called technical sound leave. Many companies brand themselves as 80+. But that's not all true. You see when AC is converted to DC, no matter how good a cooling is there will be a level of heat. On top if it, ambience can also add up to temperature on the power supply as wek. Do note that if the powersupply gets hotter, rated/proven efficiency is will drop tremendously. This is called operational temps. Many reputed brands are well known are veterans because of transparency of details. Some do not reveal the operational temp details. By today's standards the efficiency is calculated on operational temps of 40 degrees celcius~50 degrees celcius. If the operational temps are not mentioned, most likely its tested under operational temps of 25 degrees celcius, like in older generation power supply like the coolermaster 600w extreme series. On top of it, substandard powersupplies create sound when they are stressed on. A good power supply with active pfc, good wiring, caps, MOVs, cooling, casing worksmanship, etc. contribute to really good thereshold to endure stress and making sure there's no sound at the same time. Afterall, they are temperature controlled and they arent just any cheap fans. It is therefore vital to check a series of reviews and see if all the details are mentioned- as there are reviews which is used as, in reality more effective form of advertisement. If the details are not mentioned, better off taking the alternate one which has all the details. Besides why would a company hide the details if a power supply is good- unless its bad in reality.
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Why do you eve need a thick pcb board for a power supply? Why not just use best quality caps and cooling and deal with it?
How will a building be strong if the foundation is not? Better quality PCB board with equivalent thickness will help to have a better layout and components will be arranged pretty easily. Lets also not forget that better components will need good soldering, so good pcb matters, which is a main reason why one should go for a good psu. Dont be under the impression that big brands have good power supplies, learn the art of google in such scenarios.
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What do you mean +12v rails?
In a nutshell it powers majority of the system through many types of connectors. Here are the following connectors:
Main motherboard connector- in old system its a 20 plug connector- in the new ones, they are 24 power connectors. It powers major chunk of your your motherboard. In most of the new age good performance power supply- 20 pin can be detatched from the 4 pin. That is why many companies call it as 20+4 connectors. But not all companies who say 20+4 connectors necessarily means 20 pin can be split from the 4.
ATX12V connector- Its a 4 pin connector which powers another part of the motherboard. Its also a vital connector and must be connected at all times.
EPS12V connector- Same purpose as the ATX12v connector. But it gives more power which is used by high end motherboards. It has a 8 pin port. Most good reputed power supplies can split EPs 12v connector into 2 atx12v connector. Other either have one EPS 12v connector or atx 12v connector.
There are idiots out there (including so called engineers) who put atx 12v on a eatx12v plug (Note: some motherboards call the 8 pin plug on the mother either mention atx12v or eatx 12v) on the motherboard and expect it to run on full capacity. Its not that you cant do- but its best if you dont.
PCI-E connector- Its a connector which powers your graphic card. Some use 6 pin, some use 8 pin. This is another scenario where you need to do justice to the system. If you are assembling it on your own, make efforts to read the manual. Through some miraculous effort some people manage to connect 8 pin EPS12V connector on a PCI-E plug on the graphic card. This is where people make another great mistake and a possibility of a short circuit increases. For once, make efforts to read the power supply's manual- they are with a power supply for a reason. Some psu manufacturers engrave the type of connectors on the connectors itself. Welcoming for many, but if its not- it doesnt hurt to read a power supply. Many power supply come with multiple pci-e connector. It means that they can power up more than one mid range-to-high end graphic cards. But its recommended if you have atleast 50 proven amps on the +12v rails- or else a burnt power supply will be the last thing in your mind.
4 pin molex- This powers components like dvd writers, hard drives, 4 female pin molex connector based fans, fancy LED/cold cathode lights (used to decorate their system like a christmas tree) and stuff. In case of IDE type drivers, they connect the molex directly. But in case of sata- you need a sata power connector. While the new and proper have direct sata power connector, if you have old you can use molex to sata power converter. I doubt it costs more than 50 bucks, but you need to make sure that you get ample amount of sata power connectors and also molex connectors. Same thing applie for molex to pci-e converter. Majority of the companies gives this as an add-on with their graphic card. I would still recommend the direct ones.
Sata power connector- A welcoming and a useful add-on on new age power supply. They are thin and it connects to sata based drives.
Floppy connectors- Its a smaller sized connector which usually powers up floppy disks. However there are certain type of devices which requires floppy connectors- like sound cards. Asus have sound cards that require extra power. It makes sense than implementing a new type of connector. Something which you always get in standard supplies.
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What is pfc?
Long story made short- power factor correction. They simply contribute in regulating AC power input in the power supply. The modern ones we get are active pfc- or else they are obsolete and not recommended. If you want to know the difference, best if you meake efforts to google it.
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How a cooling of a power supply is maintained?
Fans and small heatsinks in certain components inside the psu. Usually the fans on the power supply suck air from inside to outside. Some fans are on the side where the cables come out from and others are on the base- usually with 120mm or even 140mm fan.Certain suck air from out to in and some blow air from in to out. Both are right but based on the pc case. The cases I prefer is where I can mount the powersupply on the base and there are air vents on the bottom. In any blow-suck air scenario fresh air is supplied and vented out- so there's always fresh air coming in and blown out. However there are also top mounted cases. If your room temps is around 27-28 degrees celcius in an average and ambience in the case is around 35 degrees Celcius and the power supply pushes air from inside to out- there's nothing to worry about. But if the air is blown from out to inside the case, there might be some disturbance. Overlockers will have some problems since the hot air from the power supply can interact with the heatsink which will disturb the basic air flow distribution funda.
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What about dual/multiple rails
There has been lots of confusion and misunderstanding about multiple +12v rails and honestly to figure it out is a time consuming work. So this is how it actually sounds like.
According to the new ATX standard, +12v rails are divided into +12v1, +12v2 and list goes on. Based on the standard, 12V1 is the 12 volt rail powers everything except the CPU. 12V2 and anything more are the +12 volt rail which powers the CPU. They aren’t real +12v rail in the first place because almost always the power supply has only one circuit to generate the +12 V outputs. So in other words one +12v rails are split into 2 or more rails. Its like plugging a device with multiple on a single power socket. The worst possibility on a split +12v rail is balanced power distribution on the DC output. This is again where company's ethics and product quality and worksmanship comes into question. A single +12v rail does work in our system, but just to fulfill the criteria of the atx standard, rails are split.
When building a high-powered computer, people (not just in India, but in other international countries) are often told misinformed that they should get a multi +12 volt rail PSU. The reason that they give is that multi 12 rail PSUs provide more power at 12 volts than single 12 volt rail PSUs. But that's not true AT ALL. If you think about it, they say that one must have a larger capacity of amps given on the +12v rails. As the point is true that demand of power on +12v rails that started making people to think about buying proper psu, there are more headaches using a multiple rail compared to a single rail. The confusion started when the standard says that 240 W in a DC output. They havent specified that it was actually supposed to be 240w per wire. Be warned- not all split +12v rail based psu doesnt follow the 240w per wire limitation. Intel has made certain efforts to display certain information about the power supplies they were able to get in hand. The power supplies and their OEMs mentioned here are only in regards to split +12v rails based. Although they werent able to put all of them due to the overwhelming brands of psu available all over the world.
Intel® Boxed Products Technical Center - ATX12V Tested Power Supply List
Unless the power supply with multiple +12v rails are tested properly and proven to be a good product, one should prevent dual/split +12v rails at all costs. Hopefully a day with come when the +12v rail funda will be back to normal with more clear information
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So the money that I pay is only for the power supply?
Nope. You also pay for the power cable as well. Some provide really good power cable for the power supply which has a blow fuse on the socket itself. If they are damaged due to a spike during power distribution- they will prevent. Note that the blow fuse on the surge protectors and on the power supply's power cable (if it has) will help only to prevent- not stop- any unexplained spike in power distribution. Sleeving and wire quality is also pretty important.
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Is there anything wrong to go for modular
Nope. Nothing wrong with it. You have to be sure that you plug in the wires properly though. That doesnt mean they will come out or anything.
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Why do companies rip people off by putting fancy wattage
I advise people- I dont work for manufacturers. Some small manufacturers pass under the scanner. Some manufacturers claim that it s a theoratical wattage calculation that us pulled from the power socket at maximum load and not the theoratical wattage on the DC output power so they get away from potential lawsuit. However not all are cheaters- some are very conservative in putting the wattage chap. This is where you need to learn to do research- nothing beats google....yet.
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What about watts calculator- are they recommended?
They calculate either maximum, average or minimum output- that's why calculations vary from one watts calculator to another. So it depends on the calculators you use. Besides the watts that are calculated are accurate. Mathematically they are, but you need to acknowledge that power supply will only pull more power from the socket if it needs to. If the system is idle- it takes low power- if you are using cpu or gpu intensive based programs, it will pull out more power.
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But I have been using el cheapos for a long time- why should I make the change now?
I would suggest to read the whole guide properly. Systems always change so certain precautions are needed. If you open your improper power supply, dont be suprised if you see some capacitors start to look like that picture. If you do, consider yourself lucky that your whole precious investment didnt come up in smoke.
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Yeah but there are people who are claiming (with photos as proof) that they can run new hardware for months and still play games which put heavy load on the machines, if this is true, why should I pay for so much?
No1 can fight or argue against human stupidity, but in this scenario one can make a sane argument.
All hardware uses capacitors and resistors which can handle such bad supply of power for a limited amount of time and load. That purely depends on the quality and type of the caps. However, no matter how good/reliable caps/resistors your hardware has, it will get damaged, eventually.
*img69.imageshack.us/img69/2101/humanstupidity.png
During the course of such damage, multiple issues are inevitable, anything from multiple BSODs, sudden over/under voltage which stresses the hardware and therefore heat and causing irreversible damage. When you send a dead hardware for replacement, they check for any visible damage- burn marks, bulging and leaking capacitors, burnt resistors, etc. If any of these damages are present, warranty will be voided and thus money is wasted. At the end of the day, its your call if you want to waste your hardware in such manner. Just to let you know that there are many who make wild and rave claims, out of which few will claim they did it their obsolete systems.
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How can you compare x brand power supply with another? There still have to be more than just amps on +12 v rails right?
El cheapos PSUs have a over-rated and under powered- most 400w probably they are actually 100w-200w at most 300-320w lasting for 5 minutes if lucky. If you use your calculators and bit of imagination about the future- its still a bigger rip off- considering the risks and the contents. Poor design, ametuer soldering, bad and thin cabling, loss of certain caps and temperature de-rating largely accounts for a system to die faster. Dropping a high-end graphic card or large capacity hard drives into your rig will prove this point. Efficiency is something does make a difference especially running 24 x 7. There's no better way of saying this with another set of words: all the wasted power is dumped as heat, which means a hotter running PSU. Every power supply has its own wear and tear cons so it will eventually die- DEAL WITH IT. Something that you should also look for its life-span is the quality of components used. An el cheapo PSU when subjected to the abuse of a demanding system will be lucky to survive more than 2 years. Capacitors, pcb boards, fans, wiring, sleeving, soldering, caps, cooling and also casing does cost a lot of time, research and effort. Besides it is logic that any elctronic device generating heat is hamper its life. So you can say more efficiency= less power loss due to heat+ longer life. An el-cheapo PSU will often skip a few nice additions like: input EMI filter, power factor correction, surge suppression, thicker gauge cables, MOVs, all solid japanese Main caps, etc. It looks more like a fancy way to connect live electricity to your pc. They come with the case for crying out loud and cost 500 bucks-1000 bucks. They have to do something to earn profits afterall this is a world that earning Rs. 50 bucks on retail is pretty cut throat. Another thing you need to know is Voltage ripple. Every PSU has voltage ripple on its outputs. A higher amount of voltage ripple = hotter it runs = sooner it can fail. How does one test if a power supply has lower ripple or not- an oscilloscope and a load tester- AKA Automatic testing equipment. The oscilloscope used to make the measurement should be set to the proper bandwidth limit. In other words, lesser ripple it shows on load, better the psu. Load tester is a big bulky machine which separates men from boys. It is used to check how powerful a psu can be. If this test doesnt pass, its a crappy power supply.
Don't expect el cheapos PSUs to have low voltage ripple- its just not feasible. Another thing you need to know is voltage regulation. If a PSU cannot regulate its outputs well, there is a much higher possibility that the psu will have a stability issue if the output drops too low under heavy load, or smoked hardware if an unloaded output shoots too high. El cheapo PSU's either do not include/have less amount of over-voltage and over-current circuit protection. In other words, if in case one of the wires or on of the rail goes spikes up, salvaging the power supply will be the last thing on your mind
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Why do I have to worry about EMI in a power supply?
Isnt your computer equally important? Every power supply MUST have a emi filter- something that all el cheapo psu will never have at all. The filter makes sure that it wont interfere with other components, and at the same time wont damage the internal component of a system- especially the hard drives. Prevention is better than cure- dont you think?
Its just not feasible for me- come on there must be a better way- right?
Here's the thing- cant afford a proper equally worthy psu, dont buy an equally worthy system. For people claiming that its better to buy 4 psu in 4 different occasions if it fails- rather than one psu, this is something that you will understand using a calculator. As said before a good power will have better effiency and power is lost. So a good PSU gives you double the power at 5 times the cost, making it effectively 2.5 times more expensive. Then my following point conveys a message that you'd probably end up replacing your generic PSU 3-4 times more over a 5 yr period than a good unit. Which effectively makes your expense the same. Not to mention the additional bits/better components that are thrown into a better PSU making it a better value! Besides, there could be a chance that replacing psu wont be the only thing to be replaced.And then comes the poor quality output from an el cheapo PSU, your components can either die a slow death due to high voltage ripple or be taken out in one swoop whenever the PSU malfunctions (or it just smoke out of cause an explosion. Factor in the cost of replacing additional hardware, and the el cheapo PSU doesn't sound feasible in the long run- compared to extra investment in advance.
If you still find it hard to believe- let this video (Credit goes to our member SURAJSPAI)
*www.corsair.com/cinema/movie.aspx?id=622747
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So can we buy any power supply with 80 plus certification with our closed?
Absolutely NOT! You will still have to read reviews and see if the 80 plus certification holds any credibility in the real world tests. Do note that power supplies tested for getting this certification are tested on labs in a controlled environment. A possibility exists that in "real time" temps, humidity and conditions (some have dusty or "dry" environment) will give out very different results which can contradict with the 80 plus certification. Do also note that Ecos Consulting, the company giving out the 80 plus certifications, tests power supplies at a room temperature of only 23º C. If you have observed, many companies brag about running this power supply on operational temps of 40~50 degrees and put this certification label on the box inorder to make a quick sale. There have been majority of the scenarios that peers with limited technical knowledge and experience, without reading a proper unadulterated review give rave advices and recommend to buy a psu solely for the certification- unfortunately its these people who don't know the difference between lab environment and real world environment- let alone the difference between 23 degrees celcius and the labelled operational temps between 40~50 degrees mentioned on the bo these days. If this is the case, even power supplies with obsolete design can get 80 plus certification very easily.
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How will I identify good power supply from bad supply? Moreover- how will I identify a good supply from another supposedly better power supply with the same cost?
This is where you need to learn the art of research and development.
# Google it out- Check the efficiency on 40- 50 degrees operational speed nothing less than this. Remember that efficiency must be tested on 40-50 degrees celcius operational temps because many places in India are hot- summers are much hotter.
# Check if its multiple rail or single rail- preferably single rail. Find out the OEM and check the OEM's reputation- websites like hardware secrets and hardwareocp usually rip the psu to the last bone.
# Check if the wires are used 16AWG and 18 AWG.
# Check if it has really good cooling, long enough cables.
# Active pfc is a must.
Note: For UPS users, certain type of ups have bit of a conflict with active pfc. However in newer systems, best if you get psu with active pfc. I am not an expert in UPS since I didn't need one.
# Check the voltage fluctuations on rails on load.
# Certain reviewers use a pc system to test a load but usually that's not the right way since it does not stresses the rails which is needed to prove the reliability of the psu and besides good power supplies usually give more - and gives an idea about fan noise. They test it with a load tester and some of them also put the videos on the same article as well to give a good idea.
# Warranty- more the warranty, more expensive the psu it is. Warranty is usually charges more by the manufacturers if the warranty period is high. Dont be under the misconception that good psu will live forever. Although psu has much better life and resistance against voltage spikes, every unit has its own breaking point. So if you find a good psu with 3-5 years, buy it.
# Any psu missing any information from the above highlighted points is something which shouldn't be ignored at all costs. If the companies or reviewers (if the reviewers didnt mention it then its most probably its an ad in a form of a "professional" review) didnt reveal the finer details- OEMS will and they have to.
Note: Powersupply advice and "myths" shouldn't be over-exaggerated unless its a bad powersupply or if there is a better psu available for the same price. Do note there have been cases of burnt computers which have been very serious such as the link below:
Techie found dead in front of burnt computer - The Times of India
Its important to have proper wiring, earthing, sockets, UPS, surge protector at the same time as well. More advance the technology gets, so must the source. Electricity is a double edge sword, respect it and you get respect. You play around with it and you will learn that electricity has a pretty electrifying sense of humour the hard way.
. I can wait till September for the further price drops, heck I'll even wait till 15th of October as Battlefield comes out on 25th October. 
