Types of Power Supplies

There seems to be a lot of different types of power supplies.(ATX/BTX , ATX12V, ATX12V/ EPS12V, ATX12V/ MicroATX ,EPS12V, MicroATX, SFX , SFX12V, TFX12V).

Does anyone know what they all mean? How do I know which one is best?

Also, what is the best way to calculate or measure the total power consumption of your PC. Why buy a 600watt PS if I only need 450?

Thanks

 

They mostly have all the same connectors,some will fit into different case geometries and have different mounts,other letters in the names are just gimmicks,you need to find out first what power supply you have,either by measuring it and the mounting screws,checking the manual of your computer or the manufacturer of your computers site or post the make and model here

You can also measure the dimensions of your power supply and its mounting holes,I cant find the link to the site that has power supply geometries ATM though, if anyone has one please post,theres 50% chance your computer has a micro atx or ATX if its a store bought computer but a 99% chance it has an ATX the most common standard if it was custom made

To work out how much power you need use this wattage calculator

http://www.jscustompcs.com/power_supply/

or post your system specs and I or another member will give you a guide as to the right size psu

Wattage doesnt really mean alot when shopping for a new power supply there are many tricks manufacturers use when specifying the amount of power the psu can give out a cheap 600 watt psu may be able to put out 600watts but only if you live in antarctica, its frozen to 0 degrees celcius and it can only give that 600watts for 5 seconds before it blows up,which is why its best to buy a quality psu from a recognized manufacturer

You also need that wattage in the right place ie mostly in the 12v rail to supply this is expressed in amps, all good psu's will have they'r Amp rating in the specifications for modern computers you want around 15- 20 amps on the 12v rail

If you post the rest of your computers specs a member will give you a link to good psu for your system

 

Double post