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Topic: 7970 from newegg $405 (Read 5462 times)

zvs
legendary
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https://web.archive.org/web/*/nogleg.com
May 01, 2012, 07:04:57 PM
#61
1) I agree here if you were a dedicated miner who just vents their air outside, but undervolting makes sense who pay electrical and cooling costs (ie. their cards are in a gaming machine). At that point your net revenue may come pretty down close to 0 after cooling costs unless you undervolt.

That is nonsense.  Gross revenue is currently ~4x electrical cost.  Even with 30% overhead for cooling it is >2x.  Undervolting doesn't improve profits.  Undervolting is useful in large farms where you simply can't handle the heat.  I updated post above to show that.
Yeah, not quite sure why some of these ppl seem more concerned with efficiency than profitability.  *scratch*   But, then, I guess you also have people loading up with 7970's that will decrease in value like nobody's business, so..

Couple months ago, I never undervolted.   Now I do so during the day only, because of heat issues (considering different solutions as to where I wouldn't have to do this).  Then, I'm speaking from a perspective of anyone that gets electricity for, oh, I don't know, probably 15-20c or so or less.  I pay ~8-9c per kwh.
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Activity: 213
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May 01, 2012, 08:56:03 AM
#60

>1 GH/s @ >5 MH/W will be interested.  The other good news is NVidia is being aggressive on performance & pricing.  AMD probably would have released it at $850-$900 had 890 flopped.  I don't think they can support that price anymore.  <$800?  Well a guy can hope.


Didn't the 6990 launch at $699?  I'm hoping the 7990 is in that ballpark when it comes out.  And $799 isn't in that ballpark Smiley
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Activity: 1218
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Gerald Davis
May 01, 2012, 08:03:45 AM
#59
For your first card it looks like 221-73 = 148W. So for that card it is 3.77 MH/J.

For your second card it looks like 380-221 = 159W. So for that card it is 3.51 MH/J.

Oh wrd.  So that is roughly the same as a 7970 on air I believe.  I can't wait to see what the 7990s will do!

My 7970s undervolted do about 570Mhash and 4.94Mhash/Watt at the wall  Wink
They do even better than that if I drop the volts all the way to <0.9V, but I lose another 50mhash/s or so in the process and my electrical rates aren't too bad as is.

7990s I'd be offended if they did worse than 5.5Mhash/Watt Tongue

>1 GH/s @ >5 MH/W will be interested.  The other good news is NVidia is being aggressive on performance & pricing.  AMD probably would have released it at $850-$900 had 890 flopped.  I don't think they can support that price anymore.  <$800?  Well a guy can hope.
sr. member
Activity: 336
Merit: 250
May 01, 2012, 05:14:52 AM
#58
For your first card it looks like 221-73 = 148W. So for that card it is 3.77 MH/J.

For your second card it looks like 380-221 = 159W. So for that card it is 3.51 MH/J.

Oh wrd.  So that is roughly the same as a 7970 on air I believe.  I can't wait to see what the 7990s will do!

My 7970s undervolted do about 570Mhash and 4.94Mhash/Watt at the wall  Wink
They do even better than that if I drop the volts all the way to <0.9V, but I lose another 50mhash/s or so in the process and my electrical rates aren't too bad as is.

7990s I'd be offended if they did worse than 5.5Mhash/Watt Tongue
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Seal Cub Clubbing Club
April 28, 2012, 10:14:57 AM
#57
For your first card it looks like 221-73 = 148W. So for that card it is 3.77 MH/J.

For your second card it looks like 380-221 = 159W. So for that card it is 3.51 MH/J.

Oh wrd.  So that is roughly the same as a 7970 on air I believe.  I can't wait to see what the 7990s will do!
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Activity: 238
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★YoBit.Net★ 350+ Coins Exchange & Dice
April 27, 2012, 10:00:30 PM
#56
Quote
No-load: 73W (not sure if I'm doing this right, but all I did was remove my video cards and power the system up and let it sit for a couple minutes)
That looks like it should be right.


Quote
So.. whatever that works out to per card in MH/j.

For your first card it looks like 221-73 = 148W. So for that card it is 3.77 MH/J.

For your second card it looks like 380-221 = 159W. So for that card it is 3.51 MH/J.

Quote
What temps were you guys running when you tok those measurements?  Azn seems to be water cooling, which apparently helps with efficiency quite a bit.

About 55C load. But when the cards are undervolted water doesn't help that much with power. I only saved 50W per card when I maxed out the voltage to 1.3V and ran 1350 MHz clocks.
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April 27, 2012, 06:51:49 AM
#55
Sapphire 5970s 899mv, 610/167MHz.  All watt readings are at the plug via Kill-a-Watt meter.

No-load: 73W (not sure if I'm doing this right, but all I did was remove my video cards and power the system up and let it sit for a couple minutes)
1-card: 122W idle
1-card load: 221W @ 558 MH/s
2-card: 171w idle
2-card load: 279W @ 558 MH/s (only 1 card mining)
2-card load: 380W @ 1116 MH/s (both cards mining)

So.. whatever that works out to per card in MH/j.

What temps were you guys running when you tok those measurements?  Azn seems to be water cooling, which apparently helps with efficiency quite a bit.

I just want to see an apples to apples comparison.
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April 27, 2012, 03:40:05 AM
#54
Sapphire 5970s 899mv, 610/167MHz.  All watt readings are at the plug via Kill-a-Watt meter.

No-load: 73W (not sure if I'm doing this right, but all I did was remove my video cards and power the system up and let it sit for a couple minutes)
1-card: 122W idle
1-card load: 221W @ 558 MH/s
2-card: 171w idle
2-card load: 279W @ 558 MH/s (only 1 card mining)
2-card load: 380W @ 1116 MH/s (both cards mining)

So.. whatever that works out to per card in MH/j.
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April 26, 2012, 11:26:11 PM
#53
Loop drained and cards tested:

No-load (remoted in with RDP to make sure system was idle and then logged out and left to idle for 2 minutes): 253W
1-card : 356W (delta 103W)
2-card load: 460W (delta 104W)

550MH/s / 104W = 5.29 MH/J card efficiency.

0.95 VCore.
Diamond Reference 7970s.

Now all that's said and done, please post some no-card, 1-card, 2 card numbers for 5970s @ 550MH/s. Please dont use idle system power with cards plugged in, because it will skew the results since you will be measuring the efficiency of idle to full-load power, not the 0 to full-load power.

I have been mining at said settings for 3 days and there are no signs of errors. All measurements are taken with Kill-A-Watt and verified with the power meter built into my APC BX1500G.
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April 26, 2012, 10:33:46 PM
#52
1) SEER 13 (min legal standard since efficiency standard) is a COP of 3.4.  Units as high as SEER 20 ( COP of 5.2)  even AC units sold in the 1980s had to be at least SEER 9 (~2.4 COP).

2) Anecdotally I know at least my home system required ~30% extra for AC consumption.

3) Still lets assume COP of only 2 (1970s era technology).  You added the AC cost to the first but not the second.

Apples to Apples would be increasing both electrical costs by 50%.  So $3.75 for full voltage rig and $3.00 for undervolted rig.  So it does save $0.75 (instead of $0.50) but still loses $2.00 in revenue.

If you have any other ridiculous claims which need refuting it will have to wait till tomorrow. Smiley

1) SEER-13 is only applicable to central air, and also doesn't take into account system-wide inefficiencies (caused by duct works, leaks, underinsulated window panes, etc etc). The overall COP of the ENTIRE system is clearly under 2.

2) That's great, not everyone has super-efficient cooling as you do. BTW if you run anything else in your house (Air-conditioner? Microwave? Electric water heater?) of course your overhead wont be 50%. You're not comparing the overhead of air-conditioning to cool ALL your appliances, some of which do not generate heat in the form of infrared radiation and thus is not exercising your air-conditioner.

3) I was talking about having it clocked so high you need to turn on A/C where the 2nd case doesnt need A/C.
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April 26, 2012, 05:22:18 PM
#51
The lower voltage really helps the 5970 keep the power usage down since switching power use rises exponentially with the voltage.  I really want to see what a 7990 with cherry-picked chips can do...

+1.  I may ditch my 5970s when the 7990s finally come out.
full member
Activity: 213
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April 26, 2012, 05:19:17 PM
#50

Where do you see 50W less per card at the same hashrate?

Code:
7970 phoenix @ 1.175V/1150/1070, 363W, 676Mh/s
5970 cgminer @ 1.05V/820/300, 377W, 761Mh/s

The 5970 & 7970 is roughly the same performance at high clock.  The 7970 has slightly higher efficiency at a modest undervolt but not this game changing nonsense you keep talking about.  Only at significantly lower clock/voltage the 7970 pulls ahead.  Of course at that significant of an undervolt the 7970 doesn't make much economical sense given FPGA still beat it in MH/W and underclocked it gives up a lot of MH/$.


The lower voltage really helps the 5970 keep the power usage down since switching power use rises exponentially with the voltage.  I really want to see what a 7990 with cherry-picked chips can do...
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Gerald Davis
April 26, 2012, 04:03:51 PM
#49
4x5970 rig
820/300 @ 1.05V
3.2 GH/s
1050 W (at the wall)
Daily revenue gross = $10.50 (current price/difficulty)
Electrical cost = -$2.503.75 (@ $0.10 per kWh)
Net Revenue = ~$8.006.25

4x5970 rig
680/300 @ 0.95V
2.6 GH/s
840W (at the wall)
Daily revenue gross = $8.50 (current price/difficulty)
Electrical cost = -$2.00 (@ $0.10 per kWh)
Net Revenue = ~$6.50



1) SEER 13 (min legal standard since efficiency standard) is a COP of 3.4.  Units as high as SEER 20 ( COP of 5.2)  even AC units sold in the 1980s had to be at least SEER 9 (~2.4 COP).

2) Anecdotally I know at least my home system required ~30% extra for AC consumption.

3) Still lets assume COP of only 2 (1970s era technology).  You added the AC cost to the first but not the second.

Apples to Apples would be increasing both electrical costs by 50%.  So $3.75 for full voltage rig and $3.00 for undervolted rig.  So it does save $0.75 (instead of $0.50) but still loses $2.00 in revenue.

If you have any other ridiculous claims which need refuting it will have to wait till tomorrow. Smiley
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April 26, 2012, 03:24:09 PM
#48
4x5970 rig
820/300 @ 1.05V
3.2 GH/s
1050 W (at the wall)
Daily revenue gross = $10.50 (current price/difficulty)
Electrical cost = -$2.503.75 (@ $0.10 per kWh)
Net Revenue = ~$8.006.25

4x5970 rig
680/300 @ 0.95V
2.6 GH/s
840W (at the wall)
Daily revenue gross = $8.50 (current price/difficulty)
Electrical cost = -$2.00 (@ $0.10 per kWh)
Net Revenue = ~$6.50

donator
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Gerald Davis
April 26, 2012, 03:14:45 PM
#47
1) I agree here if you were a dedicated miner who just vents their air outside, but undervolting makes sense who pay electrical and cooling costs (ie. their cards are in a gaming machine). At that point your net revenue may come pretty down close to 0 after cooling costs unless you undervolt.

That is nonsense.  Gross revenue is currently ~4x electrical cost.  Even with 30% overhead for cooling it is >2x.  Undervolting doesn't improve profits.  Undervolting is useful in large farms where you simply can't handle the heat.  I updated post above to show that.
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April 26, 2012, 03:12:22 PM
#46
1) It doesn't make economical sense to undervolt (at this time) given the price of Bitcoins.  I make more at full clock full voltage than I do undervolting.

2) 5970 can go much higher than 600 Mhz @ 0.95V.  I have test 680 Mhz @ 0.95V and 750 Mhz @ 1.0v.  But as I said above it actuall results in LESS net revenue (after electrical cost) to undervolt.

1) I agree here if you were a dedicated miner who just vents their air outside, but undervolting makes sense who pay electrical and cooling costs (ie. their cards are in a gaming machine). At that point your net revenue may come pretty down close to 0 after cooling costs unless you undervolt (and dont need to turn on your A/C as a result)

2) It's not valid to compare clock frequencies/voltage between different architectures. What IS valid is comparing power usage at the same hashing performance. So what power usage can you achieve at 550MH/s? Feel free to suggest any other point of reference up to ~700MH/s. Seems most 7970s can't get above that even though 5970s might.
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Gerald Davis
April 26, 2012, 03:03:33 PM
#45
The last couple of posts in this thread have been talking about mining with efficiency (ie. You pay ~10c/kwh).

Quote
5970, linux amd64, cat 11.12, sdk2.5
cgminer @ 0.95V/600/150, 273W, 542Mh/s

7970, windows 7, cat 11.12 7970 edition, sdk 2.6
phoenix @ 0.92V/925/150, 217W, 535Mh/s

1) It doesn't make economical sense to undervolt (at this time) given the price of Bitcoins.  I make more at full clock full voltage than I do undervolting.

2) 5970 can go much higher than 600 Mhz @ 0.95V.  I have test 680 Mhz @ 0.95V and 750 Mhz @ 1.0v.  But as I said above it actuall results in LESS net revenue (after electrical cost) to undervolt.


4x5970 rig
820/300 @ 1.05V
3.2 GH/s
1050 W (at the wall)
Daily revenue gross = $10.50 (current price/difficulty)
Electrical cost = -$2.50 (@ $0.10 per kWh)
Net Revenue = ~$8.00

4x5970 rig
680/300 @ 0.95V
2.6 GH/s
840W (at the wall)
Daily revenue gross = $8.50 (current price/difficulty)
Electrical cost = -$2.00 (@ $0.10 per kWh)
Net Revenue = ~$6.50

So yes undervolting does reduce electrical costs but it loses more in gross revenue.
Save $0.50 in electrical card per rig per day but lose $2.00 in gross revenue per rig per day.

Even if we assume 30% overhead due to AC cost it is still less profitable to undervolt.
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April 26, 2012, 03:03:28 PM
#44
I did find this post by ArtForz:

https://bitcointalksearch.org/topic/m.709254

...

ArtForz is showing 20% efficiency advantage to 7970.

You must have missed this then. Unless you consider 50W per card not a significant power savings.

Quote from: ArtForz
cgminer @ 0.95V/600/150, 273W, 542Mh/s

I'm not sure why Art was running his at 950mv since all of my 5970s will do 899mv/610/150, ~232W (at the wall), 554 MH/s.

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April 26, 2012, 02:56:15 PM
#43
Of course at that significant of an undervolt the 7970 doesn't make much economical sense given FPGA still beat it in MH/W and underclocked it gives up a lot of MH/$.

Post was changed. But anyways, you get $0 resale value with FPGA so your MH/$ value argument is invalid. Very few people mine a graphics card until it is worth nothing.
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Activity: 169
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Green Mining 85% Cheaper
April 26, 2012, 02:51:52 PM
#42

They're 7970s? Pretty much all of them are reference? What information were you looking for?

You guys have convinced me to drain my loop and do no-card/single-card tests tonight.

I already told you what I was looking for. Model, maybe the specific tools used to measure the outputs? Pictures? What tools used to set the speeds? How long of a mine to determine stability?

Why are you being so hostel? I own 20 7970s. I have 12 more on the way and I will let you know what I find with them. Not one of them has been able to replicate that posts findings for long term stability mining purposes. However, all of my cards are XFX Reference Design Blacks. What can possibly get hurt by sharing more information?
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