3x7970 Mining Results.

[DiabloD3]

NICE!  so if you factor in the hardware costs....  5970's will rule for a while.

How about the 5870's at bens for 140$, wonder how they will stack up to the 7970 at 550$

Well, remember, slots have a very large premium. 5970s aren't getting any faster, but the 7970 already is essentially as fast as one, and the 7990 will be twice as fast as that.

[teek]

NICE!  so if you factor in the hardware costs....  5970's will rule for a while.

How about the 5870's at bens for 140$, wonder how they will stack up to the 7970 at 550$

Well, remember, slots have a very large premium. 5970s aren't getting any faster, but the 7970 already is essentially as fast as one, and the 7990 will be twice as fast as that.

Any guesses on where the 7970 is headed with optimizations?

[DiabloD3]

NICE!  so if you factor in the hardware costs....  5970's will rule for a while.

How about the 5870's at bens for 140$, wonder how they will stack up to the 7970 at 550$

Well, remember, slots have a very large premium. 5970s aren't getting any faster, but the 7970 already is essentially as fast as one, and the 7990 will be twice as fast as that.

Any guesses on where the 7970 is headed with optimizations?

Well, before anyone had one, I said it'll probably be over 600 mhash/sec at stock speeds optimized. We're over the 500 mhash hurdle, so thats great.

[Roadhog2k5]

I don't understand these cards...

Was testing default speeds and voltages again. Mining away, drawing about 950w total system power, so I decided I would check the memory speed effect on wattage and set it to 685mhz. Right when I did that the power draw shot up to 1200w! One would assume that the wattage would decrease... Odd.

Anyways, I think I got a more accurate reading of 1375 vs 340 of 100 watts. Updated the OP again. :|

[Roadhog2k5]

Updated the OP again..... with 150mhz memory clock results.

[Roadhog2k5]

piktar.

[DiabloD3]

piktar.

Glorious, what settings?

[plastic.elastic]

OP, explain to me how watercooling would effect power efficiency.

Or you're just dreaming

[gyverlb]

OP, explain to me how watercooling would effect power efficiency.

Or you're just dreaming

WC doesn't use as much power to cool a card. As my 5970 fan failed, I used an undervolted pump with a passive radiator (a huge 360x360mm one) : it's probably the most efficient setup you can get, it only consumes ~1W.
For comparison, IIRC, depending on actual airflow around the card, the fan consumed between 10 and 20W to cool the 5970.

My GPU temperatures are lower than with the fan (when it worked correctly) too, and power usage is going slightly up with the temperature, so it should help a bit.

[P_Shep]

I think he means with water cooling he can obtain lower temps, increase stability and therefore lower the voltage further. It might work.

[Roadhog2k5]

piktar.

Glorious, what settings?

Just the default.

OP, explain to me how watercooling would effect power efficiency.

Or you're just dreaming

Not dreaming, the cooler hardware runs the more efficient it will be and in return the less power will be used. Going from 85c+ load to under 40c load is a huge difference. I saw a nice drop when I went from air to water on my 3 6970's.

[ArtForz]

Leakage current is highly temperature dependent, and a good chunk of total power consumption for sub-45nm bulk CMOS processes.
Switching speed is inversely related to temperature -> you can reduce operating voltage to "compensate" the speed gain, thus reduce dynamic and static power some more.
So yes, improved cooling can lower power consumption by a noticeable amount; No clue how much it is at 28nm, but I wouldn't be surprised if it's > 10W for 70 vs. 40 °C on these.

[DeathAndTaxes]

OP, explain to me how watercooling would effect power efficiency.

Or you're just dreaming

Higher overclock at same voltage.  System non-GPU load is now ammortized over greater number of hashes.

[plastic.elastic]

piktar.

Glorious, what settings?

Just the default.

OP, explain to me how watercooling would effect power efficiency.

Or you're just dreaming

Not dreaming, the cooler hardware runs the more efficient it will be and in return the less power will be used. Going from 85c+ load to under 40c load is a huge difference. I saw a nice drop when I went from air to water on my 3 6970's.

Yes.... cooler hardware runs more efficient. But not eligible in a scale we're talking here. What do you expect from 950w? .... 940w? LOL

And no, i'm not new to watercooling.  

ps. btw if you want to measure idle power consumption to see how much wattage these cards are pulling just by themselves, you should just remove them and boot your system with live linux. This would give you more accurate number.

[plastic.elastic]

Leakage current is highly temperature dependent, and a good chunk of total power consumption for sub-45nm bulk CMOS processes.
Switching speed is inversely related to temperature -> you can reduce operating voltage to "compensate" the speed gain, thus reduce dynamic and static power some more.
So yes, improved cooling can lower power consumption by a noticeable amount; No clue how much it is at 28nm, but I wouldn't be surprised if it's > 10W for 70 vs. 40 °C on these.

I know what you said is true, my question was to see what kind of expectation from the OP.

Altho its possible to have 40c on all these cards with watercooling, but that means his ambient temp would be damn low. I highly doubt he can save much more than 10w.

[DeathAndTaxes]

Altho its possible to have 40c on all these cards with watercooling, but that means his ambient temp would be damn low. I highly doubt he can save much more than 10w.

You fail to also consider the fact that you will be able to increase clock higher at the same voltage.  While the power draw is linear the system load is static so you improve overall SYSTEM efficiency if not card efficiency.

Alternatively you can improve stability at lower voltage for the same clock.  A 5% further reduction in voltage would result in a 9.75% reduction in power.

You also have more control over the waste heat (put radiator outside for example) and that means bringing down ambient temp at the PSU intake.  cooler PSU = more efficient PSU which further improves system efficiency.

If climates where AC is needed, dumping waste heat outside can reduce true cost of mining by 30% (or more for lower efficiency AC units).

Finally it is small but fans pull up to 6W each at full load.  That is 18W on a 3 card rig.  While radiator may need fans (although fanless radiators due exist) they tend to be larger more efficient fans (CFM per watt) resulting in a drop there.

Now if he said I can improve efficiency 70% with watercooling your "outrage" would have been justified.  His statement is accurate.  The savings may be small but the most efficient miner enjoys larger profits when price/diffculty is low and survivability when price/difficulty is high.

[Roadhog2k5]

Altho its possible to have 40c on all these cards with watercooling, but that means his ambient temp would be damn low. I highly doubt he can save much more than 10w.

You're pretty dense.

Just look at the bottom graph on this page.
http://www.silentpcreview.com/article1103-page5.html

They went from 415 watts to 386 watts, 29 watt decrease on a single 5870 by lowering the temps. That was also only a 21c temp decrease. I will be gaining at least a 40c decrease in temps. I did with my 6970's under water and saw a large decrease in power draw, and the same should be exaggerated even more on a 28nm card. BTW, No, my ambient temp stays around 72F. I just have a lot of radiator.

[phelix]

OP:
Mining: 925/1375mhz, 1.17v, 217 watts


1onevvolf:
                           Stock (925/1375MHz)
Mining                        :   371 W @ 550MH/s
Idle                            :   118 W
Difference_(gfx_card_W):   253 W
MH/J_(gfx_card_only)    :   2.17


this seems odd. I am not convinced your cards draw 0W when idle. maybe this is where the missing delta 36 watts went? (though I would only expect half of this)

if you happen to pull out a card some time it would be nice if you could make an idle measurement with a different number of cards installed so we can be sure about the idle draw.

edit:
from DeathAndTaxes' link http://www.techspot.com/review/481-amd-radeon-7970/page11.html it looks like idle wattage should be ~~15watt

[Roadhog2k5]

OP:
Mining: 925/1375mhz, 1.17v, 217 watts


1onevvolf:
                           Stock (925/1375MHz)
Mining                        :   371 W @ 550MH/s
Idle                            :   118 W
Difference_(gfx_card_W):   253 W
MH/J_(gfx_card_only)    :   2.17


this seems odd. I am not convinced your cards draw 0W when idle. maybe this is where the missing delta 36 watts went? (though I would only expect half of this)

if you happen to pull out a card some time it would be nice if you could make an idle measurement with a different number of cards installed so we can be sure about the idle draw.

edit:
from DeathAndTaxes' link http://www.techspot.com/review/481-amd-radeon-7970/page11.html it looks like idle wattage should be ~~15watt

zercore is supposed to be 3 under 3 watts idle. Even if i have the primary gpu using 13 watts idle, divide that over the 3 gpus you will still only add 4 watts onto the single gpu figure...

Also, it's not supposed to be possible for a 7970 with the power control set to 0% to draw over 250 watts. I know mine isn't drawing 250watts because I can set the power control to about -15% before it will start to throttle. -20% would be a 200 watt limit which it will obviously throttle set to that. Maybe his power supply has a really bad efficiency at that power draw.

In furmark, which is FAR more demanding than mining, without the power limit, the card only drew 270 watts...

[1onevvolf]

@Roadhog2k5: How did you manage to get the memory clocks so low? With my card I noticed that although the tool lets me select speeds down to 150MHz, it only actually respects speeds down to 975MHz, anything below that and it goes back to the default memory speeds.