Alright Im building a new PC right now and I have a question about the power supply. Well I need to know if 680 watts will be enough to power this or not, I don't know how it all works, I do know the graphics card im getting requires a minium of 540 watts, but like i dont know if that means i only have 140 left to power the rest??? and if that does i don't know if thats enough, please help.

• POWERSUPPLY: 680 Watts Power Supplies [+60] (SLI/CrossFire Ready Power Supply)
• CPU: (Sckt775)Intel® Core™ 2 Duo E8600 CPU @ 3.33GHz 1333FSB 6MB L2 Cache 64-bit [+134]
FAN: INTEL LGA775 CERTIFIED CPU FAN & HEATSINK 
• MOTHERBOARD: MSI P7N SLI-FI 750i SLI Chipset LGA775 Supports LGA775 FSB1333 DDR2/800 Mainboard w/GbLAN,USB2.0,&7.1Audio [+77]
• MEMORY: 8GB (4x2GB) PC6400 DDR2/800 Dual Channel Memory [+79] (Corsair or Major Brand)
• VIDEO: NVIDIA GeForce GTX275 896MB 16X PCIe Video Card [+226] (Major Brand Powered by NVIDIA)
MONITOR: 19" TFT Active Matrix LCD Display [+138] (Brand-Named LCD Display) 
• HDD: 500GB SATA-II 3.0Gb/s 16MB Cache 7200RPM Hard Drive
• CD: (Special Price) LG 22X DVD±R/±RW + CD-R/RW DRIVE DUAL LAYER (Black Color)
• CD2: 16X DVD ROM [+17] (BLACK COLOR)
SOUND: 3D WAVE ON-BOARD 5.1 SOUND CARD
• FLASHMEDIA: INTERNAL 12in1 Flash Media Reader/Writer [+10] (BLACK COLOR) OS: Microsoft® Windows Vista™ Ultimate w/ Service Pack 1 [+105] (64-bit Edition)

If you are using a site to build and order from, I doubt the site itself will let it pass without giving you a warning if it isn't enough.

Basically TDP(Thermal Design Power) gives you a measure of peak power requirement of a component, so you add up the TDPs of all your components. The power supply has to have twice the max. Wattage of your Total TDP to work at optimal efficiency, and keep the fan noise down (rule of thumb).

Geforce Card 275  ___  219W TDP (wikipedia)
Core2Duo E8600   ___ 65W TDP (wikipedia)
+ Chipset + HDD + 2x CD-Drives + Memory (lets say 20W each for a total of 100W)

Sum                        ___  384 W total ---(optimal PSU would be ~750 W yours is 680W)

I think your power supply will be alright. You can check out efficency grafs for PSUs at Anandtech.
 

k thanks, Well, I can get an 800 watt for only $20 more, so I think I will just do that. Thanks for your helps.

I'm pretty sure 500 would be enough.

If that 680 watt power supply is a quality one and not a cheapo it should handle the load fine.
I recommend one that is 80+ certified, bronze or silver if possible. They don't really save a ton of power, but the quality of the components they are constructed from is a big plus.

Here's a friendly suggestion: http://www.newegg.com/Product/Product.aspx?Item=N82E16817171032

700 watts 80+ Certified Silver. For $99 with the code at the top of the page and free shipping is a steal

680 seems OK to me for the setup you have in mind. Just make sure it's good quality and not some weird, cheap solution, like Lepuke said.

Go for PC Power & Cooling or Corsair brand :)