Quote from: Inaba on February 20, 2012, 05:51:12 AM

Quote from: DeathAndTaxes on February 20, 2012, 02:08:41 AM

UNDERVOLTED. 250W is at stock. Actually w/ memclock reduced it is less. I run 3x5790s. Full system 2.25 GH/s @ 870W AC (at the wall). So the idea that it is impossible is just stupid.

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This statement is just laughable. You aren't getting a 5970 to spit out 750 MH/s for 150w... that is just a joke, right? Or are you, gasp, fudging your numbers to make them look legitimate, when they are, in reality, complete bullshit... just like you're accusing BFL of doing?

Your laughable. Please educate yourself.

https://bitcointalk.org/index.php?topic=58912.0

More than one person has gotten >5MH/W with UNDERVOLTED 5870/5970. Notice the prefix "under" in undervolted as in voltage less than stock. Power consumption decreases by the SQUARE of the voltage reduction so a decent voltage reduction (say 15%) reduces power consumption by a significant amount (27% power reduction on a 15% voltage reduction).

Yes you can get >5MH/W on a 5870 or 5970. You can do the same thing w/ 7970, (and likely a 7990 also). Can you run it at stock clock? No and nobody said you could.

Before your start insulting people how about your a) READ and b) MAKE SURE YOUR ARE INFORMED.

So I just read that whole thread, and now I'm pissed. Basically, either you just lied to me and I wasted my time, which is why i'm pissed, or I completely missed the post where someone achieved 750 MH/s at 150W on a 5970. The best I saw was 550 MH/s at 250w... that's not even close. NOT. EVEN. CLOSE. So please, point out where in that thread someone achieved 750 MH/s at 150w with an undervolted 5970. I'm all over the ability to run a 5970 at 150w and I will gladly retract my statement. After you do that, if you can produce the link that I missed, I want to see it run stable for 24 hours at that voltage and hashrate.

To add insult to the injury of that thread, it was performed with a single 5970's to measure the wattage. This is a false reading - you can't compare mining wattage with idle wattage on the primary card, since the primary card is engaged in the display, thus increasing it's "idle" draw. You have to perform it on an inactive card. You need two cards in the system. Measure idle, crank up the miner on the second card and measure mining wattage to get an accurate power draw per card. Additionally, I would like to see any of those numbers stable for 24 hours. I very seriously doubt the system would remain stable for long, making the whole experiment moot, other than to show the card will run briefly at those voltages. Hell, I can OC my CPU to 6 GH/s for a benchmark run... doesn't mean I have a magical 6 GHz CPU either.

I call complete bullshit until then. I call making up numbers to make the argument possible. I call the same tactics BFL is being accused of used to bolster a counter argument.

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Note I never said it the single "barely beats" a 5970. I don't undervolt. My electrical rates are cheap I simply experimented w/ 5970 to see if I COULD when the time came and 5970 reached end of life and difficulty increases made mining at stock voltage uneconomical.

I didn't say you did, I quoted Yochdog.

He can say +/- 40% on the mh/s and +/-400% on the power consumption. BFL did and apparently, I'm wrong for thinking that is bait and switch.