I need help pick a power supply for my new computer. Can anybody help?

Question

I'd like to know how many watts I'd need for my new computer to be running best. Here's what the computer contains.

Western Digital VelociRaptor 300GB 10000 RPM SATA 3.0Gb/s

EVGA 896-P3-1264-AR GeForce GTX 260 SSC Edition 896MB 448-bit GDDR3 PCI Express 2.0 x16 HDCP

ASUS Rampage Extreme LGA 775 Intel X48 ATX Intel Motherboard

CORSAIR XMS3 DHX 4GB (4 x 1GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)

Intel Core 2 Quad Q9550 Yorkfield 2.83GHz LGA 775 95W Quad-Core

Answer 1

Assuming you have the manuals for each option you can just add up the power consumption for each adding overall, 10 to 25 percent more power than needed as a safety factor. It sounds as if you have money to spare so why don't you just go by the rule of thumb and buy the largest supply that will fit your case. Cutting corners on the supply means you might overwork a smaller supply causing a catastrophic failure. The larger supply gives you extra capability for future add-on devices.

Answer 2

Yes, I like to calculate a minimum requirement by heading over to a decent psu calculator like http://www.extreme.outervision.com/psuca... - after plug-n-chug your specs I get 279W which is the maximum worst-case scenario.  Maybe 325W to have some overclocking headroom and / or longevity for 24x7 over a few years :)

So I usually recommend a power supply that can handle at least that much power on the combined +12v rail(s)

Even this unit should have no problem handling that setup

Antec earthwatts EA380

http://www.newegg.com/Product/Product.as...

As you can see it has a +12v combined max of 324W, and is based on seasonic OEM manufacturer so it has decent quality for a budget unit (the high-rated reviews speak for themselves).

http://www.newegg.com/Product/ShowImage....

That is a good minimum unit to use, of course the more the merrier...   The 430w (+12v@360w) and 500w (+12v@408w) are also decent choices that won't break the bank

http://www.newegg.com/Product/Product.as...

http://www.newegg.com/Product/Product.as...

Another favorite of mine, Corsair's CMPSU-450VX (+12v@396w), 550VX (+12v@492w) and 520HX (+12v@480w)

http://www.newegg.com/Product/Product.as...

http://www.newegg.com/Product/Product.as...

http://www.newegg.com/Product/Product.as...

The corsair brand has legendary quality and reliability (also based on seasonic OEM with better component & build QA than Antec) and not to mention are focused on quiet performance (due to their excellent fan and controller choices).

PC Power & Cooling also make top of the line units, and the 'egg also has some killer deals on the 610W and 750W units, these are nearly 1/2 price with the instant & mail-in rebates!!

http://www.newegg.com/Product/Product.as...

http://www.newegg.com/Product/Product.as...

http://www.newegg.com/Product/Product.as...

I hope this info helps you out.

Cheers!