| The power supply keeps things in your computer | | | | no more than 10W each, optical drives even less. The |
| running smoothly. When they run well, you won't | | | | motherboard itself uses some too. The other major |
| even think about them, but when things go wrong, it | | | | user of power are graphics cards. |
| can become very annoying. | | | | As graphics cards have become more powerful, and |
| The power supply doesn't just run the power to the | | | | with the advent of Graphical Processing Units (GPUs), |
| different parts of the computer. It needs to run | | | | which are like CPUs which are dedicated to graphics |
| different voltages to different parts, and besides | | | | work, and situated on the graphics card, they can |
| that, it has to deliver them within a very tight range | | | | now use more power than a CPU. If you are running |
| set out in the ATX standard. | | | | a very fast PCIe graphics card or a pair of them, you |
| Power supplies went through a phase of being | | | | will need more power. |
| extremely unreliable. This is because the actual parts | | | | At the most basic a 300W power supply will be more |
| are very cheap and standard and the profit margin in | | | | than enough for most day to day use desktop |
| the power supply business is higher than almost any | | | | computers, even if they have a small AGP graphics |
| other computer part. The flooding of the market | | | | card. Only get more than 300W if you know you |
| with poor quality power supplies led to lots of failures | | | | need it, or expect you will need it in the future after |
| and complaints. | | | | upgrades. 500W will more than suffice for even the |
| More recently, the problems in that sector have | | | | most demanding system with 2 graphics cards, but it |
| decreased, the general quality and build of power | | | | needs to be a reputable brand. |
| supplies has increased to a level where nearly any | | | | Enermax, Antec, Fortron and Seasonic are good |
| power supply will deliver what it claims it will and | | | | names in the power supply business, you will not go |
| within specs. Most, but not all. | | | | wrong with their products. Even though there is a |
| As with computer monitors, power supplies are one | | | | small price premium, the security in knowing that |
| part that does not need to be upgraded very often. | | | | nothing will go wrong is worth it. Another power |
| The only additions have come from SATA specific | | | | supply I like is the X-connect from Ultra. Each of the |
| power plugs and the additional P4 plug in recent | | | | cables that come from the power supply are |
| years and even those are not always necessary. | | | | removable, so only the ones you are using need to |
| So what do you actually need from a power supply? | | | | be in the box. Very convenient and neat, as long as I |
| The most basic requirement is that its power output | | | | don't lose the cables. |
| can match the power needed by the components | | | | Pre-assembled computers are known for having the |
| inside your computer. Each part has its own | | | | cheapest power supplies in them. As no-one really |
| requirement and its own maximums and minimums on | | | | checks the power supply when buying they just put |
| what it needs. The claimed maximum power for each | | | | the minimum inside. These are usually fine, but will |
| voltage are added together to give the power rating | | | | often buckle under the load of extra upgrades you |
| for the power supply. | | | | may make. Bear in mind that you might have to |
| The main power user in the computer is the CPU. | | | | upgrade the power supply when installing those new, |
| Some Pentium 4 processors are known to gobble | | | | really cool graphics cards. |
| lots of power. Hard drives use some power too, but | | | | So, keep these things in mind... |