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Hi guys,


What do I need to power 4x 280x Gigabyte plus mobo? Is 1200W enough?


Thanks

1500

https://bitcointalk.org/index.php?topic=426845.0

1000W is MORE than enough for those cards. I have 1000W power supply running my 280x's just fine for months 24/7. Cheers!

Wtf? You have 4 280x running on 1000W? Are all are your cards able to reach 100% load?

...good single rail 12V PSU with more than 100A will do the trick...IMHO

Running 7950+7850 on crapy 650W PSU with two separate 12V lines 22A each

the 1200w is what you want.  The guy running the 1000w psu is likely going over 100% load.

4 280x use 1100 watts.. I got a killa watt meter

For a computer doing nothing but mining, I usually assume ~100W for the system. The best way to measure this is when the system is at idle, not mining, with 1 GPU installed. Most of our systems are usually around 75W, but I assume 100 just to be safe. This gives you some forgiveness when the HDD spins up, CPU actually does something, etc.

Our 5x 280x rig was pulling 1450W while mining. I undervolted them, and now they're drawing 1250W.

That means my kill-a-watt is telling me that my cards were running at ~270W/each, and now they're running at ~230W/each.

Whoever said 1500 didn't do any math. That's way overkill for 4 GPUs. As I said, I wasn't even pulling 1500W on my 5 GPU rig, at stock volts.

I think 1200W is your best bet. This will let you run all 4 at stock volts, or give you some headroom if you do undervolt.

I would say 1100W is on the low end, but is doable if you plan on undervolting, or if you just don't care about headroom and want to push your PSU to the max.

You MIGHT be able to squeak by with a 1000W, IF you undervolt the snot out of them, use a low power system, and don't mind pushing your PSU >100% load. I would no recommend this.

I would say this is your best bet: http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109

Another option that might be cheaper is two PSUs. Two of these would power all 4 GPUs + your rig + powered risers, and only cost you <$200, rather than >$300.

I was assuming that he was going to OC them to get the most hashing power out of them.

As I said, my 5 GPU rig was only pulling 1450 at the wall, and that was at stock volts, and overclocked. You'd be hard pressed to make a 4x 280x rig come anywhere close to 1500W. Maybe you could add a half-dozen HDDs, a few delta fans, overclocked FX-9590, and overvolt the GPUs for a balls-to-the-wall OC, and you might hit 1500W.