How to Find out SMPS / PSU Requirement for your PC

SMPS or PSU is one of the most important parts of your desktop PC. A good and proper capacity power supply is required for providing sufficient power to all your computer components so that they function properly even at full load.

smps-2SMPS or PSU comes in different wattage (W) and with different amount of current listed on 12V Rail. The amount of current on 12V Rail is the most important and deciding factor when choosing a SMPS. It is so because all the major components like CPU, Graphics Card, Hard Disk, Fans etc. draw their power from 12V Rail. Every SMPS has different amount current listed on 12V rail but you should note that this current must be sufficient enough for a SMPS or PSU of certain Wattage. This means that a 400W SMPS should have at least 30A listed on its 12V rail, a 500W should have 40A or more and so on.


12V Rail and Current Listed on it

The 12V Rail in a SMPS may or may not be divided into smaller units and if it is divided then these types of PSUs are known as multiple 12 rail power supplies.

Click here to know about Multiple Rail and Single Rail SMPS

Finding out your Power Supply Requirement

You must know that every PC has its own power requirements and for that power supplies of different capacities are available in the market. So for different PC configuration, power supply having a particular capacity is generally used. For example a PC requiring up to 400 Watt, you can use a PSU of 400W – 450 Watt but if you use a PSU of 300 Watt for that then you should face many problems like restarting, reduced performance and also you will be at a greater risk of damaging your computer components. So it is safer to use the higher capacity PSU rather than using the lower capacity one for the given power requirements of your PC. So here in this post I will show you on how to select the proper capacity SMPS for your PC.

Components that Draws Major Power in your PC

Below are the components that draws or uses major amount of power from your SMPS.


Graphics Card

Hard Disk


From the above components, Graphics Card consumes or draws the maximum amount of power when playing games or running graphics intensive applications.

SMPS / PSU Power Requirement Table

Here is a useful table to find out a rough estimate on your SMPS requirement. Please note that here I am only talking of branded power supplies only.

  CPU / Processor Graphics Card Number of Hard disks RAM Number of Cabinet Fans SMPS Requirement
PC1 Dual Core None 1 2 GB – 4 GB 1 350W – 400W
PC2 Dual Core / Quad Core Entry Level to Mainstream Graphics Card 2 4 GB or more 2 400W – 450W
PC3 Mid-range Dual Core / Quad Core / Multi Core Mid-Range Graphics Card 2 4 GB or more 3 500W – 600W
PC4 High-end Quad Core / Multi Core High End Graphics Card 3 8 GB or more 3 – 4 650W – 700W or more

If you are still unsure about your SMPS requirement then you can ask me by leaving a comment below, clearly stating your PC configuration.

Read more:

  1. rohan
    • Akshat Verma
      • Bibek Thapa Magar
      • Sayan Chakraborty
      • Ashok
  2. Madara Uchiha
    • Akshat Verma
    • vicky
  3. albin
  4. Abhigyan
      • Shalabh
  5. Abhigyan
      • Abhigyan
  6. Daniel
  7. P K SAHA
  8. Roy
      • Roy
  9. Roy
  10. Sushant
      • Sushant
          • Sushant
      • Revnth
  11. Sushant
  12. Sushant
  13. Vicky
      • Vicky
          • Vicky
  14. Vicky
  15. vicky
  16. Sam
  17. Vicky
      • Vicky
          • Vicky
          • Vicky
  18. Rajesh Sharma
  19. Gourav
  20. Ankit
    • Ankit
  21. Ankit
  22. Ankit
  23. Ankit
  24. Ankit
  25. Ankit
  26. Govind Borgaonkar
  27. anand
  28. anand
  29. anand
  30. anand
  31. anand
  32. anand
      • anand
  33. anand
  34. anand
  35. anand
  36. anand
      • anand
  37. anand
  38. Naved Khan
      • Naved Khan
          • Naved Khan
  39. Ayan
  40. Hello Motto
      • Hello Motto
  41. Yash Thakare
      • Yash Thakare
        • Yash Thakare
          • Yash Thakare
      • Abhishek Raj
          • Abhishek Raj
  43. Vicky
      • Vicky
          • Vicky
  44. Vicky
  45. Vicky
  46. Amal
      • Amal
  47. Amal
  48. Vicky
      • Vicky
          • Vicky
  49. Vicky
      • Vicky
          • Vicky
      • Jivendra
  51. Surajit das
  52. Naresh
  53. Vicky
      • Vicky
  54. Vicky
      • Vicky
  55. Govind
  56. Jayanta Kumar Mandal
  57. Rahul
  58. kunal
  59. Rizwan alam
  60. shakil
      • shakil
          • shakil
  61. Swami
  62. Shubham
  63. Sahil
  64. vinod
  65. Dibya Kanti Mondal
  66. sanjeev
      • sanjeev
      • sanjeev ghotgalkar
  67. Sameer Das
    • Sameer Das
        • Sameer Das
  68. Sameer Das
    • Sameer Das
  69. Sameer Das
  70. Milanjeet Soni
  71. Lalrinngheta
  72. Rahul Hati
  73. Rohit
  74. Umesh
      • Umesh
      • Umesh
          • Umesh
  75. Paul Martin
      • Paul Martin
  76. Paul Martin
  77. Sanjay
  78. Surendar
  79. Shivam nath
  80. Kalpesh Bankar
  81. Kaushik Dey
  82. Gaurav
  83. Gaurav
  84. MS Pathan
  85. deep
      • deep
  86. Pravin
  87. Dhruba
  88. Rahul Kapoor
      • Rahul Kapoor
  89. Sanjeev
  90. vamsi krishna
      • Vamsi krishna
  91. Vijay
  92. Jison
      • Jison
  93. Vijay
  94. Asif
  95. Huidrom Dhananjoy
      • Mohammed Nawazish Pasha
        • Mohammed Nawazish Pasha
          • nawazish
  96. rajesh
  97. vipin tiwari
  98. Gaurav Sharma
  99. Aditya K
      • Aditya K
  100. James
      • James
  101. Mahesh Rajmane
      • Mahesh Rajmane

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.