How much W for a rig like this one?

[ShitFace]

Hey guys!

So my rig is:

I5 2500K 3.3Ghz
8Gb (2x 4 RAM) 1600Mhz
Sapphire hd 6950 2Gb GDDR5 (it will be flashed to 6970, and later I will do a Crossfire with the same card)
Asus P8Z68- V/ GEN3 Socket 1155

There's a lot of saying around the bottleneck problem and i'm a little worried that that might happen because of the CPU, so I chose the K version to keep it overclocked a little so it won't be to stressfull for the CPU.

With this rig (of course with the hard drive, and DVD burner..) I need to know how much wattage i'm gonna need to run this rig?

650W or 750W? because if i choose 750 its 30-50 more dollars and i'm kinda on a budget so I don't wont to overreact and pay more for wattage i'm not gonna need... I'm asking if 650W is enough to run crossfire and all these components?

Also can you tell me if a bottleneck is even possible with my rig?

Thanks

 

[joedastudd]

650W from a good brand should be more then enough.

 

[hotthree]

You won't have a bottleneck..your parts are pretty high end so you'll be fine for a while especially if you end up overclocking down the road. Bottlenecks usually only occur when you have outdated parts or super high in gpu's with low end cpus or vice versa.

600-650watt is good...stay with corsair/xfx/antec/silverstone they have some good quality cheaper end model's (around $40-100). Other good brands include seasonic and the higher end models of the previoiusly mentioned, but they will cost you $100+.

 

[amuffin]

You will need a better psu if you plan to flash to a 6970, get 1333mhz ddr3 ram and put more towards a quality power supply. In fact if you want to crossfire you'll need even a higher end power supply which will be roughly $80. I recommend the corsair tx750w or 850w for this scenario.

 

[ShitFace]

I ran a lot of online PSU calculators, and they always trow at me a 950-1200W Power supply!! ?? why?

 

[kitsunestarwind]

Calculators always over-estimate
Same as parts manufacturers always say you need more power then what is required it's called covering their asses
Power is easy to calculate , For CPU usually estimate 20% higher then it's TDP (for safe margin) for GPU's, its each PCIe GPu can draw 75w from the PCIe bus, 75w per 6pin connector, 150w per 8pin connector (according to standards)
(so if it has 1x 6pin + 1x 8pin plugs on it, its will pull 300w (75w pcie + 75w 6pin + 150w 8pin)

That gives you your basics then go up another 100-200w depending on how much margin u want for o/c or lots of HDD's etc..