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Yet another 7770 & 400W PSU thread.

Tags:
  • Gigabyte
  • Corsair
  • Graphics
Last response: in Graphics & Displays
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October 4, 2013 4:31:06 PM

I have a Corsair 400CX 400w PSU, Gigabyte GA-970A-D3P, AMD FX-8320, 2 sticks of Corsair Vengeance DDR3 (2x4gb), a SSD, a regular SATA HD, and a PCIe x1 wireless NIC. Would I be able to run a
HIS Radeon HD 7770 GHz Edition 1GB 128-bit GDDR5 (etc etc blah blah blah) with my PSU? Its specs are as follows:

80 plus certified (yay me!)
+3.3V@20A, +5V@20A, +12V@30A, -12V@0.8A, +5VSB@2.5A
And it has a 6pin PCIe connector.

Thanks for any help.

More about : 7770 400w psu thread

October 4, 2013 4:34:53 PM

I don't see a problem.
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October 4, 2013 4:43:57 PM

You will be cutting it close but as long as you don't overclock and you don't add anything more powerful you will be just fine.
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October 4, 2013 5:03:41 PM

Thanks for the quick replies.

I used the eXtreme Power Supply Calculator (http://extreme.outervision.com/psucalculatorlite.jsp) and it came out to about 339 watts total (including my case fans, and a usb audio interface I use with my guitar). I know I'm supposed to leave maybe 10-20% overhead to play it safe (10% would be 378, 20% would be 417 - yikes!).

I have my CPU OC'd to 4GHz and its TDP is 125w. I know components rarely get to 100% wattage usage. So, I should be safe with that too? The only other thing I plan on adding is a MIDI pad controller which is powered from USB but that's practically an infinitesimal amount of power drawn.
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October 4, 2013 5:07:57 PM

Yeah you should be just fine with a 400W PSU even with the 8320 overclocked. I would suggest in the future upgrading your PSU to something around 750W so you have room to upgrade your graphics card, but with your current set-up you will be fine.
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October 4, 2013 5:13:24 PM

Awesome, thank you so much. I'm actually very relieved by this as I saw a 7770 on sale on eBay for only $74 and I just had to nab it, only to see "500w minimum power supply" everywhere.

I'll be definitely looking to upgrade my PSU. I'd love to get a modular one to cut down on the cable clutter. Even with my case, you open the back panel and it's like zombie guts spilling out. Kinda amusing, really.
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October 4, 2013 5:33:02 PM

One other thing to note. Aklthough the PSU wattage is somewhat important, when it comes to video cards, you need to not only have enough, but should have some decent headroom on the rails. For instance if the card calls for say, 32a on the +12v rail, then I would go to 40 or whatever is close to it. With Corsair, when you have the overhead on the rails, you generally have overkill on the PSU wattage.
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October 4, 2013 7:08:47 PM

I read that the 7770 needs 17A and mine is rated at 30A so I'm assuming I should be good to go as long as I don't try to overclock it, unless I get a beefier PSU.
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October 5, 2013 5:04:18 AM

You're fine with some good headroom. I had a card that required 18a on the rail and that is what I had. Did fine until I got into some intensive graphics stuff in a game and then had problems. Bought a new power supply with plenty on the rails and problem solved. With the Corsair 850w I have in here, it is overkill, but can add a second GTX 680 in sli with no problem.
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