Dual 690

Sowexly

Gawd
Joined
Dec 4, 2011
Messages
544
Alright I can't tell if I'm taking myself seriously but just to double check would a AX850 be able to run two of these cards with a 2500k pulling around 100w
 
You will definitely want at least 1000.

I find it awkward though how power is processed on the 690. One 690 uses around 425 watts, where quad SLI would require 800+.

SLI 680s or 670s would fair ok on a 650 watt psu too. O well.
 
You will definitely want at least 1000.

I find it awkward though how power is processed on the 690. One 690 uses around 425 watts, where quad SLI would require 800+.

SLI 680s or 670s would fair ok on a 650 watt psu too. O well.

Why do you find that awkward?
 
It's interesting because it seems that the card uses only 350w so I would assume two would pull ~700w
Assuming all the GPUs are being used

Regardless thanks for the info guys I think I'm gonna stick with my gut and go with 3 7970/670s whatever I feel for at the time.
 
It's interesting because it seems that the card uses only 350w so I would assume two would pull ~700w
Assuming all the GPUs are being used

Regardless thanks for the info guys I think I'm gonna stick with my gut and go with 3 7970/670s whatever I feel for at the time.

I am pretty sure your power supply can't support 3 7970. Each 7970 is rated at 250W TDP, 3 of them will pull 750w and that would only leave 100W for rest of your system if your power supply can deliver 850W on 100% efficiency. In real test from anandtech, http://www.anandtech.com/show/6025/radeon-hd-7970-ghz-edition-review-catching-up-to-gtx-680/16 , the load power of one 7970 pulled 288W when playing metro 2033 (system load power 391W - system idle power 103W), and the load power of one 7970GHz draws 329W. Three of them would be 864W and 987W respectively. Considering a good power supply runs at 85% efficiency, and rest of the system requires 150W, you would need a 1200W power supply to trifire three 7970s, or a 1350W power supply to trifire three 7970GHz at minimum.
 
A quality 1200w PSU will handle three 7970GHz no problem. You can't just subtract system idle power from system load power to get the GPU requirement because there was also a 3960X and X79 motherboard under load in those Anandtech tests.
 
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I am pretty sure your power supply can't support 3 7970. Each 7970 is rated at 250W TDP, 3 of them will pull 750w and that would only leave 100W for rest of your system if your power supply can deliver 850W on 100% efficiency. In real test from anandtech, http://www.anandtech.com/show/6025/radeon-hd-7970-ghz-edition-review-catching-up-to-gtx-680/16 , the load power of one 7970 pulled 288W when playing metro 2033 (system load power 391W - system idle power 103W), and the load power of one 7970GHz draws 329W. Three of them would be 864W and 987W respectively. Considering a good power supply runs at 85% efficiency, and rest of the system requires 150W, you would need a 1200W power supply to trifire three 7970s, or a 1350W power supply to trifire three 7970GHz at minimum.

You can't really use those #s, that is system draw, which includes CPU load. You would need to look at a tri-fire / sli review to get a better idea of how much power the card will pull.

Here we have a better idea..
http://www.hardocp.com/article/2012/03/28/nvidia_kepler_geforce_gtx_680_sli_video_card_review/8 For SLI/Xfire

http://www.hardocp.com/article/2012/04/25/geforce_gtx_680_3way_sli_radeon_7970_trifire_review/8
for Tri-Sli/tri-fire.

As you can see, entire system load doens't exceed 900W, and that is at the wall with a 2600K @ 4.8ghz, give another 15% for psu efficiency. The cards don't pull anywhere near 250-300W each.
 
It's to run a 2560x1440 2B Catleap so I can get around 100 FPS in current gen games etc
Aiming for a minimum of 40 in most titles.

I am not sure if you would need double 690's for that, but also I am gaming on 1080p and do not know what kind of burden 1440p brings to the table.

I am also interested because, I am also looking in to the 1440p 120hz 100+fps setup for gaming and will definitely upgrade from the 6970 I have.
 
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