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770 SLI...Same cards, different power..Problem?

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  • 770
  • SLI
  • Windforce
  • Graphics
Last response: in Graphics & Displays
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December 23, 2013 8:53:56 PM

I'm tossing this out here cause I may be missing something...

Picked up a second gtx 770 windforce 4gb to go with my new viewsonic vp2770.

I ordered it from the same page on amazon as my first 1, and yes, both sold and shipped by amazon..

Before installing it I compared boxes, inspected them visually. Both identical.

Popped open the case, grabbed my other 6+8 pin connector, slipped the card in, and went to plug in the power and ..what! the card takes 2-8 pins...

Looked at the box, what i thought to identical, in the fine print at the bottom, sure enough it says 2-8 pin, my original 1-6, 1-8.

Installed it anyways. Booted, activated sli, ran some tests.

The new card, installed in the top slot is getting hotter, by far, than the bottom one.
Yeah, I know the top card will run hotter. but at max load were talking 86c vs 70c.
I'm also aware the cards are rated at 95c max.

As I type, both cards are idling at 27c

Using Nvidia inspector, the card with 2-8 pins is at 1267mhz max clock, the old card is 1228mhz.
Also under overclocking the power and temp target ranges are different.
the new card 44-138%, old card 53-102%.

Is this normal? Should I get a new one? Be happy my new card seems to have higher overclocking potential?

My system:

http://pcpartpicker.com/p/2p45a





More about : 770 sli cards power problem

December 23, 2013 8:58:01 PM

you got a different card. all of those model numbers are so similar that its very easy to get 2 confused
better change them to the same clocks so you dont get micro stuttering
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December 23, 2013 9:19:28 PM

Funny, everything about the cards is identical. Besides the power connectors.

Even the boxes are identical. Besides the 1 small line on the back of the box where it states what power connectors are needed.
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December 23, 2013 9:22:17 PM

what about the model numbers?
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Best solution

December 23, 2013 9:31:51 PM

It's not a problem.

I personally wouldn't overclock them as heat/noise can go up significantly with two of those cards in a case for a rapidly diminishing return as the cards are already near the top maximum clock speed. As for micro-stutter caused by a small difference in GPU frequency, that's not likely going to happen.

*It's also possible Gigabyte discovered overclocking their ALREADY overclocked cards could run into power issues hence they may have done a "revision 2" of the same card with two 8-pins to give more power. So, another reason NOT to overclock further IMO.

Proper placement:
The card can vary the GPU frequency between the Base and Boost range which is about 5% of max (i.e. 1000 to 1050MHz), however this is affected by TEMPERATURE.

I recommend putting the card with the HIGHER frequency on top where it's likely to get warmer and thus be throttled slightly more than it would be on the bottom so both cards should perform as close as possible.

If you want to REALLY get anal about it you can monitor the GPU frequencies while benchmarking and slightly overclock and/or underclock until BOTH GPU frequencies are showing nearly the same (i.e. 1250MHz).

I don't know what kind of DIFFERENCE in GPU frequency would result in micro-stutter that otherwise wasn't there but you don't have to be exact on this. If anyone has any LINKS on this specific issue it would be nice to know.
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December 23, 2013 9:37:01 PM

throttling a card due to temps is not a good idea since you will shorten the life span considerably if you make it throttle
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December 23, 2013 9:40:46 PM

see, it is a different card :p 
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December 23, 2013 9:41:34 PM

airplanegeek said:
throttling a card due to temps is not a good idea since you will shorten the life span considerably if you make it throttle


No.
Every modern graphics card now does this automatically. NVidia calls it "GPU BOOST", AMD calls it "Powertune" I believe and it's similar to Intel's TurboBoost.

You can not turn this feature off. Here's a good explanation: http://www.anandtech.com/show/6760/nvidias-geforce-gtx-...
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December 23, 2013 9:43:23 PM

its not throttling, its making the card run faster rather than slower
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December 26, 2013 2:34:19 AM

airplanegeek said:
its not throttling, its making the card run faster rather than slower


If you are referring to my "slightly underclock" comment then be aware that a LOWER frequency makes a card last LONGER.

Throttling means to LIMIT the speed. This is the OPPOSITE to overclocking so I don't quite understand your point.

This is all academic anyway, as I suggested a SLIGHT underclock and/or overclock as needed to make the GPU frequencies be similar under load.
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December 26, 2013 7:04:43 AM

You said to throttle the top card, which is never a good idea because you want to keep components as cool as possible.
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