2X7970 Ultra low wattage

[lightlord]

Well if power costs a bit, and you happen to own a pair of 7970's

I have clocks at 850 Core Clock & 750 Memory Clock.
And voltage at 899 in Msi after burner down from 1174.

In total I pull 330 Watts at the wall. I have a wattage device that tells me.
Though not everything is tweaked completely, if I shut of 3 cores on my cpu,
and lower voltage in other areas I can properly lower it to 300 Watts.

In total I get 512M per card for total of 1024 Mhash, or 1.024 Giga hash, not bad for 330 watts.

I was just wondering, if anyone has a 7970 with better settings and lower power consumption.
Ultimately if anyone has done an equation on power consumption to bitcoin mining graph,
and where is the sweet spot.

[1714070983]

1714070983

[1714070983]

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[crazyates]

I've only got one 7970, but I ran tests to see how high I could OC it at 50mV increments. I measured the power draw and MH/s, and determined what was most profitable. I pay $0.15/kWh. This was a few months ago, so I've updated my maths to reflect the current PPS rates, and the higher price. Before, 1050/1050/375 was slightly ahead, but now it looks like 1100/1100/375 is.



I have this Gigabyte 7970, which runs at a high 1100MHz default, but with a higher than normal stock voltage as well. Undervolting made a huge difference. I didn't even include the stock 1100/375 @ 1250, as that was just too depressing.

[tacotime]

I will have to try this for LTC mining after and see if I can get big efficiency gains.  Right now I pull about 200W per 7950.

[monstrs]

For me it is now optimal settings:

mV   Engine   Mem     Mh/s   Powerdraw
962   890           160     533           232

However i would like to know how you guys determine the stability of choosen settings.
For me its hard to do, as i am doing on my computer everything else while mining, so its hard to tell when will it hang next time.

[crazyates]

For me it is now optimal settings:

mV   Engine   Mem     Mh/s   Powerdraw
962   890           160     533           232

However i would like to know how you guys determine the stability of choosen settings.
For me its hard to do, as i am doing on my computer everything else while mining, so its hard to tell when will it hang next time.

For me, it was standard OC procedures: Slowly move the clock up in 25MHz increments, until I found one that crashed. Move it back down 25MHz, and it was usually good.

[monstrs]

For me it is now optimal settings:

mV   Engine   Mem     Mh/s   Powerdraw
962   890           160     533           232

However i would like to know how you guys determine the stability of choosen settings.
For me its hard to do, as i am doing on my computer everything else while mining, so its hard to tell when will it hang next time.

For me, it was standard OC procedures: Slowly move the clock up in 25MHz increments, until I found one that crashed. Move it back down 25MHz, and it was usually good.

For me crashes are not constantly happening, it can mine a day and after that crash, how to stress test it to max for mining? I am using PC almost all the time.

[crazyates]

For me it is now optimal settings:

mV   Engine   Mem     Mh/s   Powerdraw
962   890           160     533           232

However i would like to know how you guys determine the stability of choosen settings.
For me its hard to do, as i am doing on my computer everything else while mining, so its hard to tell when will it hang next time.

For me, it was standard OC procedures: Slowly move the clock up in 25MHz increments, until I found one that crashed. Move it back down 25MHz, and it was usually good.

For me crashes are not constantly happening, it can mine a day and after that crash, how to stress test it to max for mining? I am using PC almost all the time.

Well of course crashes should not be happening. That's a good sign. You push your card until crashes DO happen, and then you back off a little. Do you know how to properly overclock?

[monstrs]

For me it is now optimal settings:

mV   Engine   Mem     Mh/s   Powerdraw
962   890           160     533           232

However i would like to know how you guys determine the stability of choosen settings.
For me its hard to do, as i am doing on my computer everything else while mining, so its hard to tell when will it hang next time.

For me, it was standard OC procedures: Slowly move the clock up in 25MHz increments, until I found one that crashed. Move it back down 25MHz, and it was usually good.

For me crashes are not constantly happening, it can mine a day and after that crash, how to stress test it to max for mining? I am using PC almost all the time.

Well of course crashes should not be happening. That's a good sign. You push your card until crashes DO happen, and then you back off a little. Do you know how to properly overclock?

Yes i know how to properly overclock
I just want to reach 100% stable clock, last settings i used had crashed yesterday, although it worked more than 24 H perfectly. Now i have to use it with 962/885 setting, so far, so good. I understand if it was standalone PC, it would be much easier to achieve.

[tacotime]

Okay, underclocking for LTC on 3x 7950s seems slightly less productive because the memory has to be run between 1200-1500MHz.  I can get my rig down to 450w (~95w per card) at 800MHz core / 1250MHz RAM / 880 mV vCore (450 KH/s/card) versus 580w (~170w per card) at 1000 MHz core / 1500 MHz RAM / 1037 mV vCore (580 KH/s/card).

450 KH/s over 95w = 4.74 KH/s/w
580 KH/s over 170w = 3.41 KH/s/w

Still, that's a pretty good power efficiency improvement.

[crazyates]

Okay, underclocking for LTC on 3x 7950s seems slightly less productive because the memory has to be run between 1200-1500MHz.  I can get my rig down to 450w (~95w per card) at 800MHz core / 1250MHz RAM / 880 mV vCore (450 KH/s/card) versus 580w (~170w per card) at 1000 MHz core / 1500 MHz RAM / 1037 mV vCore (580 KH/s/card).

450 KH/s over 95w = 4.74 KH/s/w
580 KH/s over 170w = 3.41 KH/s/w

Still, that's a pretty good power efficiency improvement.

Look at the right hand column of the excel sheet I posted. 650MHz @ 800mV got me 6.22MH/s/W for each 7970. This was the most efficient, but it was not the most profitable. Are those number you're posting the most efficient, or profitable?

[tacotime]

They're the most efficient; I calculated profitability and it was higher using higher clocks.

[crashoveride54902]

You could set your mem clock down to 700...7970's will let you do 150 from core my 7970 will do 850/700 @ 868mV...I tryed 850 but it crashed after awhile of mining so i wanted stable so i increased mV to next notch but i don't like the mh/s because end of days are near for gpus so i've been cranking everything up...dam the power bills...gimme da coins

Well if power costs a bit, and you happen to own a pair of 7970's

I have clocks at 850 Core Clock & 750 Memory Clock.
And voltage at 899 in Msi after burner down from 1174.

In total I pull 330 Watts at the wall. I have a wattage device that tells me.
Though not everything is tweaked completely, if I shut of 3 cores on my cpu,
and lower voltage in other areas I can properly lower it to 300 Watts.

In total I get 512M per card for total of 1024 Mhash, or 1.024 Giga hash, not bad for 330 watts.

I was just wondering, if anyone has a 7970 with better settings and lower power consumption.
Ultimately if anyone has done an equation on power consumption to bitcoin mining graph,
and where is the sweet spot.

[monstrs]

You could set your mem clock down to 700...7970's will let you do 150 from core my 7970 will do 850/700 @ 868mV...I tryed 850 but it crashed after awhile of mining so i wanted stable so i increased mV to next notch but i don't like the mh/s because end of days are near for gpus so i've been cranking everything up...dam the power bills...gimme da coins

Well if power costs a bit, and you happen to own a pair of 7970's

I have clocks at 850 Core Clock & 750 Memory Clock.
And voltage at 899 in Msi after burner down from 1174.

In total I pull 330 Watts at the wall. I have a wattage device that tells me.
Though not everything is tweaked completely, if I shut of 3 cores on my cpu,
and lower voltage in other areas I can properly lower it to 300 Watts.

In total I get 512M per card for total of 1024 Mhash, or 1.024 Giga hash, not bad for 330 watts.

I was just wondering, if anyone has a 7970 with better settings and lower power consumption.
Ultimately if anyone has done an equation on power consumption to bitcoin mining graph,
and where is the sweet spot.

You can do memory as low as 150Mhz on 7970, there s no need of those extra memory for mining anyways.

[crazyates]

As you can see according to my sheet, I'm running my 7970 at 375. I found it to be almost negligible power and heat compared to lower values, and actually gave me a more consistent hashrate.

However, Tacotime is mining LTC, while I'm mining BTC. He actually wants a higher mem clock, so he's doing the right thing for his situation.