how do i know how much my pc power supply need ? some said that if it more power i have the pc will go smoother but there other said that i need the equal power or else the pc will be broken.

Originally Posted by zerozone

other said that i need the equal power or else the pc will be broken.

First and foremost, that is absolutely, positively, no doubt about it, wrong!! The PC will attempt to draw all the power it needs - not all that is available. So, if your computer only needs 275 watts, and you have a 1000 watt power supply, the computer will only pull 275 watts. The only waste is in the money you spent for the extra power.

Certainly, if your PSU is failing or underpowered/strained, you may encounter strange PC behavior - odd graphics problems, or sudden reboots/freezes.

There are many PSU calculators - but I really like the new Antec eXtreme PSU Calculator. Do note when making your purchase decision, that a good power supply can carry you through several hardware upgrades, if chosen carefully. When plugging in your values, think ahead 2 or 3 years for what you might have then - such as more RAM, bigger graphics card (or 2!), more drives, etc. Don't limit your thinking to your current case as a good ATX compliant (almost all are) PSU will fit in a new ATX case. BTW, Antec is one the most trusted names in PSUs and cases (one of the reasons I trust their calculator) and I would much rather have a 500W Antec than a 600W no-name/off-brand/generic.

Note too and avoid those that say "bigger is better" - although you certainly want some buffer (you don't want the PSU to be maxed out most of the time) and growing room (for new HW), today's current crop of CPUs consume much less power than previous generations. However, today's top video cards make up for that! And if you plan on using two video cards, you will need to make sure the PSU supports that (look for SLi and Crossover support). 550W - 650W is typically plenty for all but the extreme systems. A better made supply will offer "cleaner", consistent, stable power over a wide range of demands.

Side note - if you live in an apartment, or have a toaster, refrigerator, microwave, clothes dryer, hair dryer, or stove/oven in your home, you need a good UPS with AVR (automatic voltage regulation) to protect your PSU and PC from anomalies on the power line.

ok thanks.