Quad HD 7970 Bitcoin Miner - PSU Req.?

[TheAce]

Holy crap 0.27 per kWh? dammmnn... I pay .06

You in the States? Nuke power? We mainly use coal. Australian's have a phobia on Nuclear power. Sad really... 

hmm i live in Czech Republic and we have here nuclear power, but we pay also about $0,2 .. thats a sad story here.

[QuiveringGibbage]

MINER DOWN!! .. Half down. I have here 2 x 7970 GHz Edition cards sitting here collecting dust and depreciating in value...

Anyone ever experience extreme fluctuation in their hash rates? When I run 3 x 7970s, 2 of my cards fluctuate wildly between <100MH/s to 300MH/s. They will do that for about 2-5mins and then either SICK and DIE or I loose video out put and PC response.

It's stable on 2 cards. I'm on cgminer 2.11.3 with 13.1 AMD Drivers. Ubuntu12.10.

ckolivas suggested "not enough power QG" on IRC which I had suspected too but I after pulling out an old PSU to power the 3rd card, no difference. Same scenario. Hangs or 2 cards will die. I tried different combinations of power supply to each cards and swapped PCI positions. No difference.

Motherboard maybe? AsRock Extreme9 mobo.

I'm on currently only doing 1Gh/s on dual 7970s. I want MORE POWER!!

QG

[Tejsei3]

Holy crap 0.27 per kWh? dammmnn... I pay .06

You in the States? Nuke power? We mainly use coal. Australian's have a phobia on Nuclear power. Sad really... 

hmm i live in Czech Republic and we have here nuclear power, but we pay also about $0,2 .. thats a sad story here.

I pay 0.06 kw/h

Has anyone created a map or database of power rates? Would be interesting to see where the best place is to locate a farm, if you've got that flexibility.

[zif33rs]

you should be getting way better hash off those cards. check your flags...check your fan speed. you have it set to auto? if so set to manual at least 80%...open case....the cards can run at 100c but below 80c is much much better. you need more airflow. also...the wild fluctuations are probably your card going in and out of "boost" mode....setting the gpu core and mem speeds manually is preferred. try setting the core at 1050-1100mhz(should hold at stock voltages, if not bump vcore) and the memory to 800mhz(lower mem voltage if you can 1.5v? default should be 1.6v).  you can flag these setting thru cgminer i believe but i use msi afterburner. YMMV.

zif

[freebeer2go]

You need 1200W, otherwise risk burning your mobo.

[QuiveringGibbage]

Yo yo maa,

I've been soo busy making modifications I haven't had a chance to update. My rig has transformed into a 2 storey.. building/box/thing. I have hand crafted an extension to my case (btw, I feel like such a noob buying a case now...) and added 6 PC fans. I might get some pics if anyone's interested a taking a peak.

It has come to my realisation that my Corsair AX1200i may be a little under powered. Nothing bad has happened, yet, but it's debatable whether or not 1200W is enough to power the might of 4 x Gigabyte HD 7970 GHz Edition.

So, I was in #ozcoin and Graet pointed out my cards were over heating in the confined space of my case and is not getting enough air flow. In turn I purchased 4 x 12inch PCIe risers to raise my cards from my case, then encase them in a wind tunnel box thing I built out of MDF. Now my cards are tuned to E:1100Mhz, M:1200Mhz, V:1.256, P:15, I:7 and it gets me 700GH/s on each card, sometimes it gets up to 750. 3.0GH/s BABY!! YEEHAA!!

All this power comes at a cost tho, my Steplight power meter reads ~1305W at the wall and it hit a Max. of 1400W. I'm not too worried, I pick this PSU cause I've seen good results from stress test. Just not sure how long they will last tho.

QG

[Tejsei3]

So I bought a Steplight Power Meter to monitor the power being drawn from the wall. This result is only with 1 x 7970 card. Haven't bought additional 3 yet, Monday...

I worked out from our last Energy Australia bill that I pay an average rate of 27 cents / kWh.

Data -
Total Time Running:   1728mins
Total Watts Used:       5227W
Average Cost / kWh:   $0.27
Average Hash Rate:    520MHs

Calculator Estimates - from http://blockchained.com/profit/index.php?hashrate=520&cost=1&electricity=0.27&power=181&months=1.0000&decline=0.63&blockcoins=0
At the current Difficulty of 4367876, currently paying 25BTC / Block and current BTC value is at AUD$43.43, the calculator estimate I should get back (excludes capital cost):

After 1 month: AUD$40.94 (or approx. 1BTC)
After 1 week:   AUD$10      (approx. 0.25BTC)

Results so far -
After only 6 days and nights of mining with, several hours of down time (server upgrades and my own mucking around), lets say a week for simplicity, I have:

Pending Payout (confirmed):    0.22547869 BTC (which if sold at current price is AUD$9.79)

According to my calculations it will cost me around $35/month for electricity. Which means I'll probably break even on running cost... I can live with that!!!

Anyone care to check my numbers??

Cheers,
QG

Take a close look at your electric bill. Some utilities use a tiered approach, so that you pay a lower rate for the first hundred kWh's and more as you consume more. For example, you might pay .16/kWh for tier 1  and .24/kWh for tier 2, and your normal electrical usage puts you into tier 3, which is .30/kWh. Since you are adding demand in tier 3 the rate you should be using is .30/kWh, not the average.

[Spendulus]

Holy crap 0.27 per kWh? dammmnn... I pay .06

You in the States? Nuke power? We mainly use coal. Australian's have a phobia on Nuclear power. Sad really... 

You guys HAVE cheap power, it's just that your government thinks it's green to tax you on energy.  Nothing cheaper than coal.  But yeah, for bitcoin mining, power costs must be considered....

[superfry]

Have you searched static ice for the GPU's? Recently built a dual 7970 rig and the cards were 410 a pop. Also rigged up a dual power supply system to (2x 600w Antec's we had laying around).

[drahgon]

This is a little off-topic but have you taken into consideration that you might not make that much with that rig after ASIC is "fully" deployed?
Meaning you're spending almost $2000 in a system that will give you about 8 BTC a month with current difficulty, therefore you'll be making about U$S240 gross profit (deduct power consumption) and that profit will be declining as ASIC improves the difficulty, not to mention the fact that BTC can go down in price also and your ROI will be longer than a year, if not more...
You might be better off buying $2000 worth of BTC and hoping they go up.
Just saying...

I agree!!  Buy BTC instead..   

He could mine an alternative coin as well and hope it goes up.

[Nathaniel B]

Anyone have numbers on the 7970s overclocked mining litecoins? I'm hoping that an 800W PSU will be enough, but it looks like I might need 850W.

[GuiltySpark343]

In turn I purchased 4 x 12inch PCIe risers to raise my cards from my case, then encase them in a wind tunnel box thing I built out of MDF.

Can you give me a name or link or pic of the 12inch risers you are using? I'm looking for some myself, thanks!

[zif33rs]

In turn I purchased 4 x 12inch PCIe risers to raise my cards from my case, then encase them in a wind tunnel box thing I built out of MDF.

Can you give me a name or link or pic of the 12inch risers you are using? I'm looking for some myself, thanks!

Talk to this dude.   https://bitcointalk.org/index.php?topic=6128.0  


Great service.

[mccminer]

My system is designed for four 7970's & I went with the Lightning-1300 watt PSU.  I'm only running three in it right now, but plan on adding the fourth in the near future.  Haven't had any PSU issues, and don't foresee any in the future.  I'm a definite believer in providing more than adequate power.  An old man once told me:  "those who buy cheap, buy twice."

[pantehicon]

My ASUS 7950 runs very cool, even when overclocked. They *really* cut down the power consumption on that chipset apparently. I was going to point out about not fitting on that board (I've got the same one and I can only just fit 2 cards in). Be careful not to have them jammed hard against each other.  A few mm of spacing will save you a lot of pain.

I'm 'only' running an 800W power supply and having no problem running two cards (The second one is a 5830 which actually draws more than the 7950). Apart from that I'm running close to what you've got, and it's totally overkill

[Wilderness]

grats on your system, I've also built a 4 x 7970 rig recently and in aus too

mine is built and mining well in BAMT but have done 0 optimisation, that is next though I do love the stability of stock settings :p
got another rig with 2 x 7950's just today and getting SICK on the second card. You have any luck resolving your SICK status? If so was it just changing miner?

[joesmoe2012]

Dual 1000 would be my recommendation.

[QuiveringGibbage]

http://imgur.com/a/mRbMZ   <== Pictures

My Steplight power meter currently reads ~1400W

But I'm ok with that... for now.

Can you give me a name or link or pic of the 12inch risers you are using? I'm looking for some myself, thanks!

Talk to this dude.   https://bitcointalk.org/index.php?topic=6128.0  
Great service.

I was going to try that Cablesaurus but they didn't have 12inch ones. I got mine from http://stores.ebay.com.au/Micro-SATA-Cables they are based in the US but the risers have Flyconn on them (China). Tho, the last time I checked Micro Sata Cables they stoped listing the 12 inch ones. Sold out maybe?

QG

[LiveJay]

You mentioned that you were running cgminer on Ubuntu.  I'm running a similar setup with 2x7970.  I'm getting slightly lower hash rates, ~600MH/s per card.  Can you tell me what your command line looks like?  And what versions of the driver and OpenCL package you are using?

Thanks,

-Jay

[QuiveringGibbage]

got another rig with 2 x 7950's just today and getting SICK on the second card. You have any luck resolving your SICK status? If so was it just changing miner?

how hot are they running? and how high is your Engine? I had to cool my my cards and lower the clocks to stop them going SICK and DEAD.

You mentioned that you were running cgminer on Ubuntu.  I'm running a similar setup with 2x7970.  I'm getting slightly lower hash rates, ~600MH/s per card.  Can you tell me what your command line looks like?  And what versions of the driver and OpenCL package you are using?

http://imgur.com/a/mRbMZ#y6zZ4pi   that's in Win7 tho. but pretty much the same card config. AMD 13.1 drivers.

QG