How many watts shopuld a decwent power supply have for a gaming PC

[fallenapples]

I'm going to buy a new psu for my new PC which will be used for gaming. Its current psu is 450 watts. Now I intend on buying a powerful graphics card...about 1GB DRR2 Memory, but I may even get one with less or a more powerful one in the future. How many watts should my psu be just to be safe? And how will I know it will be compatible with my MOBO? The website does not tell you how many watts the graphics cards require to run.

 

[masteroc]

For one powerful graphics card and (I assume) a dual-quad core cpu I would say a good 550-600 watt power supply would be good. If you are looking to do SLI either now or in the future I would go up to around 700. Just imo...there are some psu wattage calculators out there you could check on also.

 

[xGodlyPoison]

Newegg has a power supply calculator that suggests a wattage of a power supply that would support your build. All it requires is filling in a few things(general type of motherboard, video card, etc.) no personal details or anything.

Newegg - Power Supply Calculator

 

[EnToxication]

750 for decent gaming computer.

 

[Fat.Clown]

time after time, wattage calculators has proven themselves to be a joke
most of them are designed with lousy PSU's in mind

anyways...

how many watts your system requires really just depend on what you are putting in your system

obviously you aren't going to grab a power hungry not to mention expensive GTX 295 to go with your 450W PSU

respectively with 1000W PSU, nobody is going to pair it up with a 9400GT

that being said, for a single card configuration, 500W should be more than enough, even if you grab the power hungry HD 5870


on another note to OP, do not be fooled by the watts rating

now a days you should be looking at the amp rating on the 12V rails and build quality

a DYNAPOWER PSU won't come anywhere close to a Seasonic or Enermax

 

[Nubbleet]

Yeah, like said above, it's not only the watts what matter. The amount of amps on the 12V rail is very important, as well as the company that makes it. Also it is preferable to have a single 12V rail as opposed to multiple.

 

[S0ULphIRE]

^Don't know about that (the single vs multiple rail thing). In fact, I'm sure it doesn't matter. Whether you're pushing 100A on one 12v rail or 25A on 4 12v rails the output is the same and will power the same amount of hardware.

 

[zedman3d]

^Don't know about that (the single vs multiple rail thing). In fact, I'm sure it doesn't matter. Whether you're pushing 100A on one 12v rail or 25A on 4 12v rails the output is the same and will power the same amount of hardware.

Not exactly. If you know your video cards are sucking up the majority of the amps, and their respective PCIE power connectors run of say 2 of the 4 rails your PSU has, then it can only use what the 2 rails deliver to it. The other two rails go to cpu, harddrives, etc and most of the time, a bit wasted.

By having one rail, you can better distribute the amps/watts. The video cards take as much as they need, so does the cpu and everything else.

 

[S0ULphIRE]

Not exactly. If you know your video cards are sucking up the majority of the amps, and their respective PCIE power connectors run of say 2 of the 4 rails your PSU has, then it can only use what the 2 rails deliver to it. The other two rails go to cpu, harddrives, etc and most of the time, a bit wasted.

By having one rail, you can better distribute the amps/watts. The video cards take as much as they need, so does the cpu and everything else.

I guess the multi rail PSUs get around this by having rails that are not 'balanced' (e.g. one rail has 18A, one has 20A, and the other two have 24A). So the 18A rail is used for the cpu and hdds, while the higher amperage rails are for the GPUs.

Even with a single rail PSU you're not going to be utilising exactly 100% of the power available. Sure there's probably some loss with multi rail models when they supply so much to the cpu/hdds but that loss is still gonna be in the single rail models.

garh, I'm not so good at explaining stuff I guess I'd say the single rail design has a slight advantage if you're running a bunch of GPUs and then needed to connect 10 hdds as well, but honestly in real life application there's not that much difference IMO.

 

[zedman3d]

Yeah the balanced thing is true. There are for sure ones that have something like 2x 18a then 2x 24a.