Watts

[Stephen]

I was just wondering how many watts I would need for my first build. I am planning on running a 7790, an 13 3220, an asus motherboard, and 4x2gb memory plus 2-3 fans.

[Stephen]

forgot to add an ssd and an optical drive to the list

[Guest]

youll be safe with a 500-760watts. get other peoples views too.

[Mdgtman91]

500-600 would be plenty but if you plan on upgrading later go a lil bigger like 750 or so just to give that room to put what ever you want in there

[Andi]

youll be safe with a 500-760watts. get other peoples views too.

 are you crazy? :D this system pulls under max load not even 150W...so 200W psu would be enough. But you can't buy so small PSU's so buy a good 300/350W

[Guest]

 are you crazy? :D this system pulls under max load not even 150W...so 200W psu would be enough. But you can't buy so small PSU's so buy a good 300/350W

 yes but you dont want to strap your system to such a tight power limit. im sure the guy want to have some kind of flexibility in the way that he can upgrade. by throwing in a beefier graphics card.

[blknight88]

If you aren't planning on upgrading anytime soon then I would recommend a lower wattage power supply.

Your systems needs roughly 200 watts so in order to stay within the efficiency rated for 80 plus power supply's you want to get a PSU 

that your system can stay within the 20-80% range.

So with 200 watts full load that would be 50% of the output of a 400 watt PSU and 20% of 400 watts is 80 watts which would make your system fairly efficient at idle too.

I would recommend at least an 80 plus bronze 400 watt PSU with your current system.

[Andi]

 yes but you dont want to strap your system to such a tight power limit. im sure the guy want to have some kind of flexibility in the way that he can upgrade. by throwing in a beefier graphics card.

 you need a 500W psu for a 3570k+ 7970. 750W "to be safe" would be enough for a SLI Setup....these numbers are so far from reality. And if he wanted to upgrade in the future he could tell us that and than we  could give him a higher watt number..

[Guest]

 you need a 500W psu for a 3570k+ 7970. 750W "to be safe" would be enough for a SLI Setup....these numbers are so far from reality. And if he wanted to upgrade in the future he could tell us that and than we  could give him a higher watt number..

Exactly man i agree, but all i was saying is that you shouldn't limit your build :)

[Silentsoul]

Here is the calculator that JonnyGuru uses

 

http://www.extreme.outervision.com/psucalculatorlite.jsp

[Andi]

Exactly man i agree, but all i was saying is that you shouldn't limit your build :)

a 3220 + 7790 would need something like 25W in idle and psu's are really inefficient with low loads - there is a downside to buying a way to big psu. I mean even a 300W unit runs at 10% with maybe 78% efficency if its a 80+Bronze psu. A 600W unit would run at 5% and 75% efficency or even less

[mgsstar]

I would get a 500W psu for your build. I would recommend the SILVERSTONE Strider Plus ST50F-P 500W.

[pierrelucsav]

I recommend going 650 or 750, so when you upgrade you won't need to worry about the power supply.

[Glenwing]

Just to be clear 750W is way overkill for your build as it is; however the power supply is something that never gets "outdated" or obsolete, it's something you can keep re-using in future builds, so if you have the money to spend a 750W would be enough for pretty much any future system up to two-way SLI/CrossFire.

 

As for your current system a 450W would be more than enough power, and that would be enough to handle any single GPU upgrade as well (although it won't be the most efficient hehe).  One of my machines is almost identical to that and running off of a 250W power supply.  Even 550W would be overkill.  Just make sure you get a reputable unit like a SeaSonic or something, most lesser brands' 450W power supplies are actually 300-350W units in disguise ;)