In this post I will share about the details and factors that you should be looking at while Choosing Power Supply for a PC. PSU, the Power S...
In this post I will share about the details and factors that you should be looking at while Choosing Power Supply for a PC.
PSU, the Power Supply Unit of a Computer system aka SMPS, is an important part of every computer. Choosing power supply for a PC can be a difficult task if you fall for the jargon. It is one of the most important components that will go inside the Cabinet. If the CPU is the brain of the PC then the SMPS is the fuel source. It is that important!
Choosing Power Supply for a PC- An Overview
80 Plus ratings, 12v rails, wattage, OCP, OVP, passive cooling, fully modular.. These are the common terms that are thrown around while selling a PSU. For an average Joe, these terms are just stupid acronyms. But it is important to know about these terms because the whole power supply concept is based on these terms.
Buy PSUs on Amazon.in at best prices!
Buy PSUs on Amazon.com
The PSUs don't get the respect that they deserve. People buy the cheapest one with the highest wattage rating and later pay up more than they invested. They do not realize the problems of a low quality PSU until other components are fried by it. A small voltage fluctuation and BAM!!.. It takes the HDD with it. All your collection goes with it. I know this because I speak from experience. So that you don't go through the same hassles, I have compiled this guide to tell about the basic features that you should be looking for while choosing power supply for a PC.
Watts
The Power Supply Unit, as the name implies is the component which supplies power to your components. Its main function is to convert AC from the outlet to DC. On a side note, I wonder why they don't call it a Power Converter Unit. This power of the PSU is measured in Watts. So a power supply rated at 400W has the capacity to supply approximately 400W. Notice that I have used the word "approximately"; because in practical conditions this output may very. This output also changes drastically with the change in temperature.
The number of Watts gives a rough idea whether a particular PSU is capable of handling the power drawn by the whole system. A powerful graphics card setup can easily draw 200W whereas a small PC does not even need 200W of power. You see the difference here.
As a general suggestion- any modern single GPU based PC will not need more than 500W. This is just a rough estimate but still a strong one.
Always leave a bit of headroom when calculating the PSU output. This will help you when you will upgrade the components down the lane. Though they are not accurate, you can take help of the following resource to calculate the power draw-
Outervision Power Supply Calculator
But it is not the only important deciding factor..
Peak vs Continuous Output
This factor is very crucial now. Cheap knock-off PSU makers only label the Peak Output and not the Continuous Output. So what is the difference here?
The peak output here is the maximum output of a PSU. This means that a 400W PSU
transfer 700W but only for a very short period. It can do it for 1 sec or even an hour. After that just pray to God that the other components are alive.
Continuous power on the other hand is the maximum power that a PSU can sustain for a long period under the right conditions. A 500W PSU will continuously give 500W under the correct temperature and load.
READ This TOO Choosing a PC Case- A Short GuidePowered by Inline Related Posts
When going over through PSUs, stay away from the models which only provide Peak Output info. Don't even consider them and pray that they choke on their own cables and DIE!
Volts, Amps and Rails
The power from the outlet is not directly sent to the components. First it is converted into DC and then separated into different voltages like 12V, 5V, 3.3V. These are the common voltages on which the computer components run. The CPU, graphics card and maybe fans and HDDs are handled by the 12V and other peripherals are powered by the 5V and 3.3V line. Though this may vary among different PSUs.
A spec sheet from the CM Silent Pro 700W.
Notice the power and amps on different rails.
The voltage in a PSU remains constant; it is the current that is varied according to the requirements of the component. It is measured in Amps. This current passes through "Rails" or copper pathways on the PCB. Some rails handle the 12V and some others handle the 5V and 3.3V lines. This seems simple enough but this is where the confusion begins. There are multi-rail systems and single rail systems. The single rail will supply all of the current through this path whereas in a multi rail system, it is divided into more than one path.
Which is better then? There is no clear answer, but the basic convention says that if you are going for a high end PSU with more than 1000W of power, then a multi-rail system is the way to go or else modern single-rail designs from reputable manufacturers are great. There are no other benefits associated with a particular path distribution.
Now the question arises about how many amps do you actually need on rails. This requirement is usually listed on the power requirements of a graphics card, or a CPU. To put it in brief, for a single GPU setup you will need minimum 20Amps on the 12V rail. And as you increase the components, then this number will only go higher.
Efficiency
Remember I wrote earlier in the article that a 400W unit will supply 'approximately' 400W. This is where the efficiency factor comes into play. The power is converted and because the laws of the Universe suck, some of the power is lost in this conversion. Lower the power loss of a unit, higher is its efficiency.
The PSU manufacturers all around the world are using the 80Plus efficiency certification standard. A PSU is awarded a badge according to its efficiency. There are many levels. You might have seen the 80Plus bronze, silver, gold and platinum logos on PSU spec sheet. A bronze certified PSU is 83% efficient in conversion and other levels provide even higher efficiency, Platinum certified PSU is over 90% efficient. Keep in mind though, these efficiency levels goes on decreasing as you ramp up the load. High efficiency levels are reached in the 50%-70% load range.
Now do you really need the Platinum certification for a mid range unit? Well the answer is no. See, highly certified PSUs are expensive and to reap the benefits of bills saved by a high end unit is not completely justified for the price you pay. Still 80plus Bronze certification is the minimum you should be looking for in a PSU.
Protection Systems
The majority of the power of a system is transferred on the 12V line. For example, a 700W PSU will have almost 550-600W of power on the 12V line. Which is around 50A on the 12V line (V*I=P). Now if you put components here which draw more than this current, the OCP (Over Current Protection) will kick in and shut down the system to protect it. The same goes with the OVP (Over Voltage Protection). If somehow the voltage increases, the OVP will act. Some of the protection measures are-
READ This TOO Best Graphics Cards in India - 2016 GuidePowered by Inline Related Posts
Source- TomsHardware
There are many other protection systems present in modern PSUs. The more you have them, the better it is.The only thing you should be caring is the presence of the features. Some of the most basic ones might omit them but it is a rare case.
Ripple Filtration
Ripple is the equivalent to the noise in an audio line, or fireflies in a render, or everything that you don't need in the transferred power. The study of ripple suppression and filtering is a fascinating one and is beyond the scope of this article. So instead of explaining it here, I will let the pros do the talking. Here is a link to Overclock.net where this topic is explained in a thorough way.
Ripple Suppression- OCN
Still to tell you in a brief, ripples are
They are the reason for premature aging of components and cause problems in long run if they are left unfiltered.You don't want them in your system and unfortunately you cannot know about this feature just by looking at the spec sheet. You will have to do some research on your own side for this.
You can read professional PSU review sites like Johnyguru, HardOCP or HardwareSecrets. They are the best sites that will give you all the technical information of a PSU you need while choosing a power supply for a PC.
Cables and Connectors
In terms of cables, there are three types of PSUs. Non-modular, Semi-modular and Fully-Modular.
Non-Modular - The cables in this type of PSU, are hardwired to the PSU board. They cannot be removed and are usually reasons for ugly looking cable clutter, especially for bigger sized units with lots of cables.
A non modular PSU from Corsair value series
Semi-Modular - Only two or three cables are hardwired to the PSU board and others are modular that is removable. Only the absolutely necessary cables are hardwired, this mainly includes the 24-Pin, 8-Pin and sometimes the PCI Cables.
A semi-modular PSU from Corsair CX series
Fully- Modular - All the cables are removable. Though the interface between the PSU and the cables vary and have proprietary inserts.
A top of the line modular PSU from corsair's HXi line
There are many power connectors in a computer system. The major ones are-
20+4 pin Motherboard Connector- This is the biggest connector of PC and it supplies power directly to the motherboard and its components. Because of its size, this is the hardest cable to manage and hide. The 20+4 pin means that the pin can actually support both 20 and 24 pin motherboards.
24 ATX connector
4+4 pin CPU/EPS Connector- This is the cable that directly supplies power to the CPU. The 8 pin port is usually located in the top area of the motherboard and if your case is large then sometimes the cable may not reach the motherboard port at all. So if you have a large case, consider the length of this cable too. The 4+4 pin design denotes that it can support both 4 and 8 pin motherboards.
4+4 pin EPS connector
6+2/6/8 pin PCI Connector- This is connector cable is used for powering the PCI devices like the graphics cards. There are three variations- 6+2 design, supporting both 6 and 8 pin cards; 6 pin for 6 pin and 8 pin for 8 (duh!).
6+2 PCI connector
Molex Connectors- The molex name is a misnomer. Molex is a company which manufactures connectors and the real name is peripheral or accessory connector. It is used for powering up devices like fans, LED lights, fan controllers or even water cooling pumps. Even some graphics cards are powered by molex connectors using adapters.
Molex connector
Drive Connectors- This is a flat connector and is used for powering up drives like HDDs or DVD readers.
A SATA power connector
Other Factors to Consider
If you keep in mind the above mentioned factors, then you will definitely get a decent PSU. But if you want the best of everything, then here are some more features-
READ This TOO Choosing a Hard Drive for PC - A Short GuidePowered by Inline Related Posts
Cable design- The cables of a PSU can be naked, sleeved or flat styled. The sleeved cables look the best when sleeved properly. The flat styled cables are supplied with many high-end PSUs and they are easier to manage. But they look boring. And then there you have the naked ones.. the black, red, yellow spaghetti. The cable design has no performance value, it is just a personal aesthetic preference.
Digital Control- i line of Corsair PSUs are digitally controlled. The current conversion, switching, fan operation. many tasks are operated digitally. Though this is not absolutely necessary, but you know you need it!
The small port on the left side of the photo is used for digital monitoring.
Fan-less operation- if you are a anti-PC-noise person then this feature if for you. Fans spin and so create noise. So some manufacturers have zero decibel PSUs (load based or passively cooled).
OEM- this factor is an important one. Many manufacturers in reality do not produce their own PSUs, they source it whole from other manufacturers or simply provide the designs to the manufacturers. This is the reason why even manufacturers like Cooler Master were shamed because of their original GX line, which was manufactured by a not so good OEM. To find out about the OEMs, you will have to go looking for reviews for the particular model that you are interested in. A great place to start will be this: Who's Who of PSUs- TomsHardware
Wrapping it UP
So this was a small guide which I compiled for you guys to help in choosing Power Supply for a PC. Yes the article is long and NO, I don't intend to make it any shorter. In contrast, I wanted to add even more information, but that will be beyond the scope of this article.
The whole process can be boiled down to one step.
Read professional reviews, ask questions on forums, look for customer reviews and then repeat the steps. Do this until you are fully satisfied with the PSU you have chosen! The PSU may not be the most expensive part of your system but this is the guardian that protects those Titans and X99 Haswell-E.
Buy PSUs on Amazon.in at best prices!
Buy PSUs on Amazon.com
PSU, the Power Supply Unit of a Computer system aka SMPS, is an important part of every computer. Choosing power supply for a PC can be a difficult task if you fall for the jargon. It is one of the most important components that will go inside the Cabinet. If the CPU is the brain of the PC then the SMPS is the fuel source. It is that important!
Choosing Power Supply for a PC- An Overview
80 Plus ratings, 12v rails, wattage, OCP, OVP, passive cooling, fully modular.. These are the common terms that are thrown around while selling a PSU. For an average Joe, these terms are just stupid acronyms. But it is important to know about these terms because the whole power supply concept is based on these terms.
Buy PSUs on Amazon.in at best prices!
Buy PSUs on Amazon.com
The PSUs don't get the respect that they deserve. People buy the cheapest one with the highest wattage rating and later pay up more than they invested. They do not realize the problems of a low quality PSU until other components are fried by it. A small voltage fluctuation and BAM!!.. It takes the HDD with it. All your collection goes with it. I know this because I speak from experience. So that you don't go through the same hassles, I have compiled this guide to tell about the basic features that you should be looking for while choosing power supply for a PC.
Watts
The Power Supply Unit, as the name implies is the component which supplies power to your components. Its main function is to convert AC from the outlet to DC. On a side note, I wonder why they don't call it a Power Converter Unit. This power of the PSU is measured in Watts. So a power supply rated at 400W has the capacity to supply approximately 400W. Notice that I have used the word "approximately"; because in practical conditions this output may very. This output also changes drastically with the change in temperature.
The number of Watts gives a rough idea whether a particular PSU is capable of handling the power drawn by the whole system. A powerful graphics card setup can easily draw 200W whereas a small PC does not even need 200W of power. You see the difference here.
As a general suggestion- any modern single GPU based PC will not need more than 500W. This is just a rough estimate but still a strong one.
Always leave a bit of headroom when calculating the PSU output. This will help you when you will upgrade the components down the lane. Though they are not accurate, you can take help of the following resource to calculate the power draw-
Outervision Power Supply Calculator
But it is not the only important deciding factor..
Peak vs Continuous Output
This factor is very crucial now. Cheap knock-off PSU makers only label the Peak Output and not the Continuous Output. So what is the difference here?
The peak output here is the maximum output of a PSU. This means that a 400W PSU
can
transfer 700W but only for a very short period. It can do it for 1 sec or even an hour. After that just pray to God that the other components are alive.
Continuous power on the other hand is the maximum power that a PSU can sustain for a long period under the right conditions. A 500W PSU will continuously give 500W under the correct temperature and load.
READ This TOO Choosing a PC Case- A Short GuidePowered by Inline Related Posts
When going over through PSUs, stay away from the models which only provide Peak Output info. Don't even consider them and pray that they choke on their own cables and DIE!
Volts, Amps and Rails
The power from the outlet is not directly sent to the components. First it is converted into DC and then separated into different voltages like 12V, 5V, 3.3V. These are the common voltages on which the computer components run. The CPU, graphics card and maybe fans and HDDs are handled by the 12V and other peripherals are powered by the 5V and 3.3V line. Though this may vary among different PSUs.
A spec sheet from the CM Silent Pro 700W.
Notice the power and amps on different rails.
The voltage in a PSU remains constant; it is the current that is varied according to the requirements of the component. It is measured in Amps. This current passes through "Rails" or copper pathways on the PCB. Some rails handle the 12V and some others handle the 5V and 3.3V lines. This seems simple enough but this is where the confusion begins. There are multi-rail systems and single rail systems. The single rail will supply all of the current through this path whereas in a multi rail system, it is divided into more than one path.
Which is better then? There is no clear answer, but the basic convention says that if you are going for a high end PSU with more than 1000W of power, then a multi-rail system is the way to go or else modern single-rail designs from reputable manufacturers are great. There are no other benefits associated with a particular path distribution.
Now the question arises about how many amps do you actually need on rails. This requirement is usually listed on the power requirements of a graphics card, or a CPU. To put it in brief, for a single GPU setup you will need minimum 20Amps on the 12V rail. And as you increase the components, then this number will only go higher.
Efficiency
Remember I wrote earlier in the article that a 400W unit will supply 'approximately' 400W. This is where the efficiency factor comes into play. The power is converted and because the laws of the Universe suck, some of the power is lost in this conversion. Lower the power loss of a unit, higher is its efficiency.
The PSU manufacturers all around the world are using the 80Plus efficiency certification standard. A PSU is awarded a badge according to its efficiency. There are many levels. You might have seen the 80Plus bronze, silver, gold and platinum logos on PSU spec sheet. A bronze certified PSU is 83% efficient in conversion and other levels provide even higher efficiency, Platinum certified PSU is over 90% efficient. Keep in mind though, these efficiency levels goes on decreasing as you ramp up the load. High efficiency levels are reached in the 50%-70% load range.
An 80Plus certified (80% efficient) 500W PSU will actually pull around 600W from the wall socket.
Now do you really need the Platinum certification for a mid range unit? Well the answer is no. See, highly certified PSUs are expensive and to reap the benefits of bills saved by a high end unit is not completely justified for the price you pay. Still 80plus Bronze certification is the minimum you should be looking for in a PSU.
Protection Systems
The majority of the power of a system is transferred on the 12V line. For example, a 700W PSU will have almost 550-600W of power on the 12V line. Which is around 50A on the 12V line (V*I=P). Now if you put components here which draw more than this current, the OCP (Over Current Protection) will kick in and shut down the system to protect it. The same goes with the OVP (Over Voltage Protection). If somehow the voltage increases, the OVP will act. Some of the protection measures are-
- OCP (Over Current Protection): protection against power spikes
- OVP (Over Voltage Protection)
- OPP (Over Power Protection): overload protection, sometimes called OLP
- OTP (Over Temperature Protection): protection from overheating
- UVP (Under Voltage Protection)
- SCP (Short Circuit Protection)
- NLO (No Load Operation): this isn't exactly protection in the same sense as the other features, but it allows the PSU to power up and function normally, even with no load.
READ This TOO Best Graphics Cards in India - 2016 GuidePowered by Inline Related Posts
Source- TomsHardware
There are many other protection systems present in modern PSUs. The more you have them, the better it is.The only thing you should be caring is the presence of the features. Some of the most basic ones might omit them but it is a rare case.
Ripple Filtration
Ripple is the equivalent to the noise in an audio line, or fireflies in a render, or everything that you don't need in the transferred power. The study of ripple suppression and filtering is a fascinating one and is beyond the scope of this article. So instead of explaining it here, I will let the pros do the talking. Here is a link to Overclock.net where this topic is explained in a thorough way.
Ripple Suppression- OCN
Still to tell you in a brief, ripples are
BAD!
They are the reason for premature aging of components and cause problems in long run if they are left unfiltered.You don't want them in your system and unfortunately you cannot know about this feature just by looking at the spec sheet. You will have to do some research on your own side for this.
You can read professional PSU review sites like Johnyguru, HardOCP or HardwareSecrets. They are the best sites that will give you all the technical information of a PSU you need while choosing a power supply for a PC.
Cables and Connectors
In terms of cables, there are three types of PSUs. Non-modular, Semi-modular and Fully-Modular.
Non-Modular - The cables in this type of PSU, are hardwired to the PSU board. They cannot be removed and are usually reasons for ugly looking cable clutter, especially for bigger sized units with lots of cables.
A non modular PSU from Corsair value series
Semi-Modular - Only two or three cables are hardwired to the PSU board and others are modular that is removable. Only the absolutely necessary cables are hardwired, this mainly includes the 24-Pin, 8-Pin and sometimes the PCI Cables.
A semi-modular PSU from Corsair CX series
Fully- Modular - All the cables are removable. Though the interface between the PSU and the cables vary and have proprietary inserts.
A top of the line modular PSU from corsair's HXi line
There are many power connectors in a computer system. The major ones are-
20+4 pin Motherboard Connector- This is the biggest connector of PC and it supplies power directly to the motherboard and its components. Because of its size, this is the hardest cable to manage and hide. The 20+4 pin means that the pin can actually support both 20 and 24 pin motherboards.
24 ATX connector
4+4 pin CPU/EPS Connector- This is the cable that directly supplies power to the CPU. The 8 pin port is usually located in the top area of the motherboard and if your case is large then sometimes the cable may not reach the motherboard port at all. So if you have a large case, consider the length of this cable too. The 4+4 pin design denotes that it can support both 4 and 8 pin motherboards.
4+4 pin EPS connector
6+2/6/8 pin PCI Connector- This is connector cable is used for powering the PCI devices like the graphics cards. There are three variations- 6+2 design, supporting both 6 and 8 pin cards; 6 pin for 6 pin and 8 pin for 8 (duh!).
6+2 PCI connector
Molex Connectors- The molex name is a misnomer. Molex is a company which manufactures connectors and the real name is peripheral or accessory connector. It is used for powering up devices like fans, LED lights, fan controllers or even water cooling pumps. Even some graphics cards are powered by molex connectors using adapters.
Molex connector
Drive Connectors- This is a flat connector and is used for powering up drives like HDDs or DVD readers.
A SATA power connector
Other Factors to Consider
If you keep in mind the above mentioned factors, then you will definitely get a decent PSU. But if you want the best of everything, then here are some more features-
READ This TOO Choosing a Hard Drive for PC - A Short GuidePowered by Inline Related Posts
Cable design- The cables of a PSU can be naked, sleeved or flat styled. The sleeved cables look the best when sleeved properly. The flat styled cables are supplied with many high-end PSUs and they are easier to manage. But they look boring. And then there you have the naked ones.. the black, red, yellow spaghetti. The cable design has no performance value, it is just a personal aesthetic preference.
Digital Control- i line of Corsair PSUs are digitally controlled. The current conversion, switching, fan operation. many tasks are operated digitally. Though this is not absolutely necessary, but you know you need it!
The small port on the left side of the photo is used for digital monitoring.
Fan-less operation- if you are a anti-PC-noise person then this feature if for you. Fans spin and so create noise. So some manufacturers have zero decibel PSUs (load based or passively cooled).
OEM- this factor is an important one. Many manufacturers in reality do not produce their own PSUs, they source it whole from other manufacturers or simply provide the designs to the manufacturers. This is the reason why even manufacturers like Cooler Master were shamed because of their original GX line, which was manufactured by a not so good OEM. To find out about the OEMs, you will have to go looking for reviews for the particular model that you are interested in. A great place to start will be this: Who's Who of PSUs- TomsHardware
Wrapping it UP
So this was a small guide which I compiled for you guys to help in choosing Power Supply for a PC. Yes the article is long and NO, I don't intend to make it any shorter. In contrast, I wanted to add even more information, but that will be beyond the scope of this article.
The whole process can be boiled down to one step.
RESEARCH and REPEAT,
Read professional reviews, ask questions on forums, look for customer reviews and then repeat the steps. Do this until you are fully satisfied with the PSU you have chosen! The PSU may not be the most expensive part of your system but this is the guardian that protects those Titans and X99 Haswell-E.
Never ever go cheap with your PSU.
Buy PSUs on Amazon.in at best prices!
Buy PSUs on Amazon.com
So thanks for giving your time to this article. If you had a good time reading this article or felt that this post helped you in some way, then please leave a comment below or share it on social media and make me famous!
