PSU needed for basic overclocked i5 750 / 5850 crossfire rig?

Azhigher

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Jul 13, 2010
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Ok folks, I've been mulling this over for a while now and can't seem to find a clear answer...

The basic question is thus: Do I need a 650w PSU or 750 for a basic overclocked i5 750 / 5850 crossfire rig.

Rig:

ASUS P7P55D-E Pro LGA 1156 Intel P55 SATA 6Gb/s USB 3.0 ATX Intel Motherboard

Intel Core i5-750 Lynnfield 2.66GHz LGA 1156 95W Quad-Core Processor BX80605I5750

2x HIS H585FN1GD Radeon HD 5850 (Cypress Pro) 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card w/ Eyefinity

G.SKILL ECO Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL7D-4GBECO

Spinpoint F3 HD, Antec 900 case, dvd-RW, usb mouse/keyboard, blah blah blah

I'd like to overclock the i5 to around 3.5-3.6 ghz or so and overclock the 5850's as much as I can with the CCC (Not a whole lot, really)

So there it is, different PSU calculators have given me different answers. Seems like some say a good 650 will be fine, others warn I'm cutting it too close and need a 750. What say you forum?


Thanks for any input =)
 
Solution
don't worry about watts as much as amps among other things. you could go with any name brand such as corsair, Seasonic, XFX.... and you really cant go wrong at 650 or 750 watts.

sorry its not a clear "get this" answer but its good for you to make your own decision

wardy22

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Dec 20, 2008
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don't worry about watts as much as amps among other things. you could go with any name brand such as corsair, Seasonic, XFX.... and you really cant go wrong at 650 or 750 watts.

sorry its not a clear "get this" answer but its good for you to make your own decision
 
Solution
D

Deleted member 217926

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A single 5850 will run fine with a quality 450w PSU like the Corsair 450CX. If you are running 2 x 5850s a 550w CorsairTX will handle it fine. The 650TX is actually on sale for the same price as the 550 right now so you might as well give yourself some room to upgrade in the future. Now ATI lists this:

ATI Radeon™ HD5850 System Requirements:

PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard

500 Watt or greater power supply with two 75 watt, 6-pin, PCI Express® power connectors.

600 Watt or greater power supply with four 75 watt, 6-pin, PCI Express® power connectors for ATI CrossFireX™ technology in dual mode.


ATI Radeon™ HD5870 System Requirements:

PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard.

500 Watt or greater power supply with two, 75 watt, 6-pin, PCI Express® power connectors.

600 Watt or greater power supply with four, 75 watt, 6-pin, PCI Express® connectors for ATI CrossFireX™ technology in dual mode.

Corsair and other quality manufacturers actually provide more power than they are rated for. The above would be for a generic PSU not a high quality one.

http://www.newegg.com/Product/Product.aspx?nm_mc=AFC-SlickDeals&cm_mmc=AFC-SlickDeals-_-NA-_-NA-_-NA&Item=N82E16817139005