| If there is any one component that is extremely vital to | | | | BLUE -12 V |
| the operation of a computer, it is the power supply. | | | | RED +5 V |
| The power supply should be the highest priority when | | | | WHITE -5 V (May not be present on recently |
| choosing components; if working with a set budget, | | | | manufactured supplies) |
| invest in the power supply and make compromise | | | | BLACK GND |
| elsewhere. The power supply is perhaps the most | | | | GREEN POWER-ON (Active high -- must be shorted |
| significant module in every computer system as it | | | | to ground to force power up) |
| supplies stable, consistent power to every other | | | | GRAY POWER-OK |
| component in the system, | | | | PURPLE +5 V STANDBY |
| Power supplies must not produce and dissipate too | | | | BROWN +3.3 V REMOTE SENSING |
| much heat or noise. Bad power supplies are almost | | | | (please check with the specification of the |
| always overrated in their peak wattage number. A | | | | manufacturer which may vary) |
| thumb rule is that one should purchase as much good | | | | Ensure that the sockets fit into the components well. |
| quality power supply as one can afford to ward off | | | | Go for one with 20-pin/24-pin ATX Socket (as |
| sudden breakdowns, data corruption and possibly | | | | required) and enough 12V Molex Sockets (4-Pin Molex |
| physical component damage. If you are building a | | | | Connector/Serial ATA Connector/PCI-Express |
| brand new system, go for anything over 400 watts. | | | | Connector) to power different peripherals inside the |
| Select the power supply that fits into the cabinet you | | | | computer box. Now-a-days modular power supplies |
| have chosen. Also make sure that there is enough | | | | are available where the cable can be plugged and |
| clearance so that it does on interfere with other | | | | unplugged to many sockets provided in the power |
| occupants of the cabinet. Choose a Power supply | | | | supply. In this case one has to use only as much |
| compatible with the motherboard and the other | | | | cables as needed. This prevents the inside of the |
| components you are planning to fit into the case and | | | | cabinet from cluttering. It is wise to use sleeved cables. |
| also one that offers additional plugs in case of | | | | Go for the power supply with a cooling fan and lesser |
| upgrades of the computer later on. | | | | noise. Never trust a vender for his words. Go for a |
| Almost all computer power supplies have three | | | | more superior, trusted and reliable one, even if it costs |
| voltage rails (3.3V rail, the 5V rail, and the 12V rail). | | | | more. It will give you years of comfort. |
| Wiring coming off an industry standard circuit board will | | | | I must repeat again that the power supply should be |
| be: | | | | the highest priority when choosing components; if |
| ORANGE +3.3 V | | | | working with a set budget, invest in the power supply |
| YELLOW +12 V | | | | and compromise elsewhere. |