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Adding Graphics Card - PSU Still Enough?

  • Homebuilt
  • Overclocking
  • Graphics Cards
  • Systems
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Last response: in Systems
February 25, 2010 8:46:09 PM

Overclocking and PSU Analysis

I've decided I want to put a bit more juice in my system, so I plan to Crossfire my SAPPHIRE 100282SR Radeon HD 5850 1GB. I've plugged these into this calculator, but some of the values I was unsure about in regards to overclocking and capacitor aging. This is what I have, and if I decide to add another graphics card, should I consider upping my PSU? Thank you in advance!

Intel Core i7-920 Bloomfield 2.66GHz ($288.99)

Cooler Master 212

Lian Li Lancool PC-K62

ASRock X58 Extreme

G.SKILL 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600

Graphics Cards
SAPPHIRE 100282SR Radeon HD 5850 1GB

Hard Drives
Samsung Spinpoint F3 1TB (x2)
Intel X25-M SATA II 80GB

Power Supply
OCZ ModXStream Pro OCZ700MXSP 700W ATX12V V2.2

DVD Burner
LITE-ON Black 24X DVD+R 24X DVD-R SATA Black 24X DVD Writer LightScribe Support

Card Reader
Koutech IO-RCM620 USB 2.0 3.5" Card Reader

Will 700W be enough? Thank you! :) 

More about : adding graphics card psu

a b B Homebuilt system
a b K Overclocking
a b U Graphics card
February 25, 2010 9:00:42 PM

Yes-- you will be fine with the 700w modstream. The second card adds no more than 160w to your system--and you had a lot more than that to give.

(I edited to 160 after seeing the difference between 305w and 469w ... lol. )
a b B Homebuilt system
a b K Overclocking
a b U Graphics card
February 25, 2010 9:04:35 PM

This might help-- this is the full system power usage in the Tom's 5850 review article:

Test system: (your system will use quite a bit less-- as you havent yet overclocked to 4ghz.)
Intel Core i7-975 Extreme (Bloomfield) 3.33 GHz, 6.4 GT/s, 8 MB L3 Cache, power-saving settings disabled
Overclocked to 4 GHz (25 * 160 MHz)
Asus Rampage II Extreme (LGA 1366) X58/ICH10, BIOS 1504
Corsair Dominator 6GB (3 x 2GB) DDR3-1600 8-8-8-24 @ 1,600 MHz
Intel SSDSA2MH160G2C1 160 GB SATA 3 Gb/s
Realtek RTC8111C, 1 Gbps
Graphics Cards ATI Radeon HD 5850 1GB

Full article :,2433...
Related resources
a b B Homebuilt system
a c 171 K Overclocking
a c 247 U Graphics card
February 25, 2010 11:01:45 PM

For the calculators:

-The 920 you can OC to 4 Ghz at 1.35 volts
-If you use a hig quality PSU (9.5 or better at, use 10% capacitor aging ....add 5% for each 0.5 drop in performancerating .....not really scientific but it seems reasonable .... :) 

If you must go OCZ, at least get the Z series....the *stream's have not been reviewed very well:

I'd get a Corsair 650TX or Antec EA-650

Intel 930 supposed to be out before Monday.
a b B Homebuilt system
a b K Overclocking
a b U Graphics card
February 25, 2010 11:35:29 PM

Hey Jack... hes listing what he already has--not shopping.

While there are definitely better PSUs out there, I think this one will work for him.
a c 122 B Homebuilt system
a c 197 K Overclocking
a b U Graphics card
February 26, 2010 7:42:04 AM

It's better than you think. That 560 watt figure is from the wall. Figuring 80% efficiency, the computer is using about 450 watts from the PSU. That means the PSU is running at about 65% load (450/700).