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Hi Folks,

How best to power x2 Radeon R9270's? Do I need to spend the extra bucks on 1000w psu? Cards arrived today off to get proc in the morning. Any recommendations/tips?

Thanks guys!

Icobur

I always go for the reviews to see what kind of power consumption I can expect:

http://www.tomshardware.com/reviews/radeon-r9-270-review-benchmarks,3669-9.html

One card on its own seems to draw a bit less than 150W (which makes sense given the one PCI-E connector). Therefore with 2 cards, you're looking at 300W. Add an overclocked CPU and other stuff gets you at still less than 500W. Therefore, in my opinion, no, you do not need a 1000W power supply. However, you still want a GOOD power supply, not the 250W PSU that claims to be a 600W PSU.

http://www.coolermaster.outervision.com/PSUEngine

you can use that website to calculate the wattage you need

Indeed, a decent brand 600watt PSU should be enough. If you want to be certain, then take a 750watts.. Then you should definatively be safe, IF you use a good brand. Try to do some research on the internet because there's a lot of difference between the PSU's

PSU are fairly cheap right now, just throw in a 1000w which will allow you to upgrade later on.
Always better to have too rather than not enough

R9-270s draw slightly less than their 7870 counterpart (http://www.anandtech.com/show/7503/the-amd-radeon-r9-270x-270-review-feat-asus-his), so about 150W-180W. If you're powering two of them, you'd need a ~700W power supply to be safe. 1000W is not necessary, but it of course depends on what else you estimate to be drawing from the power supply (e.g. a CPU, motherboard, hard drives, etc.).

Liberal estimate of power required:

CPU + motherboard ~100W
Other components (hard drive, USB, etc.): ~30W
Fans: ~20W
Graphics cards: 300 - 460W:
---------------------
 = 610W, nowhere near 1000W.

Not necessarily: Check out a good review and look at the efficiency curve of a PSU. Normally they're the most efficient (least wasted energy) at about 50% of their rated load. If you get a 1200W PSU for instance, you may get less efficiency because you're not drawing enough.

When you're counting energy consumption over several months of mining as part of your calculation for profit, every percentage point counts! If your plan is to buy more cards later, that may be a different story. However, I have never done my "upgrade plan" exactly as I thought.

I think it's enought about 600 or 650 Watt PSU for 2 this cards.

My 3x7870 cards run with 750W.

But it must be fair watts. And not very hot CPU.

if you had more cards you could also get multiple cheap power supllies (e.g. 750-1000W) and connect them with with special connector, e.g. ADD2PSU. add2psu.com

I recon the cards will be running hot and using juice. It's not quite the conventional gaming they're usually designed for.

And remember that Seasonic X-series Gold are the best cost/effective PSU's it's very reliable on the long term and are great energy savers :) (Have the 1250W myself for three 7950)

Currently running 2 LEPA 700w bridged together ... think I paid about $85 each and the bridge cable was $5. So for 2 80plus Gold PSU's at $170 for a guaranteed 1120w of juice isn't too bad.