I have tested some more. Release 74 is using more power and heat, so the card trottle and performance is lost.
My test was conducted in a closed case rig with a EVGA superclocked card (2x 6pins power)
but my dev card:
The gigabyte 970oc G1 comes with 1x8 pin and 1x6 pin and doesn't trottle and give bether performance in release 74 than 66.
SP_, all 5.2 maxwells do at least 1500MHz under load. In open case, limiting factor is TDP. Nothing to do with power pins.
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Testing how far I can go with reference 970. You need to give this baby almost +300 to get there (1500). Around 10500 kH/s mining lyra2v2.
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Same settings with quark, hitting TDP and only hashing about 17200 kH/s. TDP mod is all you need if you want to get all out of these.
It has to do with power pins: max TDP depends on how the card is powered. I have two kinds of 970 and the max TDP is higher on the one that has one 8 pin and one 6 pins instead of 2x6.
Furthermore, the power you need to reach a certain frequency varies based on a lot of variables like room temperature, efficiency of cooling, fan speed, the chip itself, etc.
Correlation does not imply causation. I have some cards with less pins that draw more power then ones with more pins.
the power is drawn (?) from the card, meaning it doesn't depends of the number of pins (however if there are not enough pins, the card won't be able to get what it needs to work... and/or the pins will try to carry a higher intensity than the one designed for...