Author

Topic: Radeon 7970 (Read 2585 times)

legendary
Activity: 1666
Merit: 1000
February 28, 2012, 11:25:06 PM
#6
Speaking as someone with 2 4x7970 rigs  Tongue

Running Seasonic 1250 gold psu...

1050/900 :: 225-230 per card (1060-1080 for the rig).

1150/1000 :: 245-255 per card (1130-1150 for the rig).

Each rig has 2 x 120x35mm Delta fans that eat ~10W per - so you could drop these numbers by 20W, accordingly.

full member
Activity: 180
Merit: 100
February 28, 2012, 12:37:22 PM
#5
I was going to try and get four 7970 into one rig. Are they worth the money and would an 850 power supply work.  I currently run 2 5870', 2 5850's on one of these power supplies.  If not any suggestion on power supply. 

7970 require 8 pin and 6 pin connectors, two connectors per card.  Probably 150-200W on the 8 pin cable, another 50-100 on the 6 pin cable.

Now, you figure out the right PSU for your 4 card setup.

or PSU'S

As for them being worth the money, I'm running a single right now and am happy with the output. I plan on adding 3 more in the next month or so, unless the 7990's come out.
newbie
Activity: 38
Merit: 0
February 28, 2012, 11:36:10 AM
#4
Not saying you shouldn't have some breathing room; but for you consideration:
I ran 2x Radeon HD6990's (combined with: i5 2500K, 8Gb RAM, 1 SSD, 1 HDD, 5 Fans) 24/7 for a couple of months on a Seasonic PSU rated for 850W, before repurposing the system for everyday use. Works fine, still.

Granted, I did undervolt the GPU's; but they still pumped out 1520 Mh/s.
donator
Activity: 1218
Merit: 1079
Gerald Davis
February 28, 2012, 11:06:02 AM
#3
1200 or 1250W PSU should be fine if:
a) good brand
b) high efficiency (80-Plus Gold or better).

850W is a good way to kill a PSU or the hardware or you (when your significant other kills your for burning down the house).
legendary
Activity: 1372
Merit: 1003
February 28, 2012, 10:16:21 AM
#2
I was going to try and get four 7970 into one rig. Are they worth the money and would an 850 power supply work.  I currently run 2 5870', 2 5850's on one of these power supplies.  If not any suggestion on power supply. 

Each Radeon HD 7970 uses 250W under load so do the maths.  I think you would need at least a 1400W PSU if you were to run 24/7 and you wanted the PSU to last over twelve months.
sr. member
Activity: 308
Merit: 250
February 28, 2012, 09:59:28 AM
#1
I was going to try and get four 7970 into one rig. Are they worth the money and would an 850 power supply work.  I currently run 2 5870', 2 5850's on one of these power supplies.  If not any suggestion on power supply. 
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