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.
Yeah right...
I have 6 maxwells 5.2 + 3x 750ti and only 1 of them is able to do a stable 1500+. All of them are over 1400 but no way to do a stable 1500 without a vcore rise.
Each of them was slowly overclocked by 20Mhz step. When I have noticed any crash of a miner I put it 20Mhz back. Gigabyte G1 970 was also benchmarked in some Windows "gaming" benchmarks.
Those are the clocks I'm using 24/7 without any stability problem and temperatures from 65-74°C:
gigabyte G1 980 1450Mhz
gigabyte G1 970 1560Mhz
3x Asus strix dc2oc 970 1440/1450/1480 Mhz
960 1411 Mhz
3x 750ti 1400/1420/1440 Mhz
Btw I don't care optimizing H/W ratio, because the electricity price is still low at my location.
With the r.74 I get more or less the same speeds as in r.66.