Topic: Large hashrate variance in SAPPHIRE 100351SR Radeon HD 7970 3GB 384-bit GDDR5 PC (Read 1740 times)

You're very welcome.

It sounds like a fun venture that you've gotten into. Thanks for all of the insight and back story on your situation -- it's very interesting. Your setup is without a doubt impressive! It's good that your builder is enjoying the project too. You sound like a very nice person to work for.

For monitoring your rigs from home, I think it should be possible to use a piece of software called CGWatcher. See here: https://bitcointalksearch.org/topic/cgwatcher-140-a-guimonitor-for-cgminer-bfgminer-to-help-minimize-downtime-159267
Essentially, CGWatcher is a program that connects to cgminer and can monitor it and even change the configuration or other settings. CGWatcher provides a nice, easy graphical interface to cgminer (which is commandline-only). I've not yet tried it myself but I've been meaning to as it looks quite excellent. With some initial setup and basic security considerations, I think CGWatcher could probably fulfill most all of your needs.

As for insurance, I'm not really sure. I don't have any experience in that area, sorry. My rigs are not insured... (hmm, now you have me thinking! ).

Thanks so much for this reply--it is very helpful to me!!  The parts for the set up came to about 10.9K, and he we bought a cooling A/C system and they just did a lot of fancy wiring with an electrician--so total cost after rebates, shipping and everything is 11.1K

The rig is going to live at this place, and I will pay for the labor he put in with part of the proceeds.  The builder is overjoyed that it works and I don't want to seem critical (he's like a kid who just got a 11K toy--and I'm very happy for him and happy to see that my confidence in him and his ideas about cryptocurrency has been such a nice boon for him financially and emotionally)--just want to get a feel for what the numbers are going to add up to in terms of paying off the investment.  I'm good at the financial side of this--calculating difficulty, versus price--figuring out other currency strategies to mine, etc.--just need to get a realistic feel for the hashrates assumptions upon which to base my analysis.

Is there any way you might know of besides coinotron for me to monitor things remotely from my computer at home?  Is cgminer something he could hook up to allow me to monitor?

I am also concerned about insuring the whole operation for theft and weather loss--and he hasn't gotten very far with that as he has been so busy building...thinking maybe I should call in my own insurance people but not sure what to insure the rigs at.  Should I insure just the cost of the parts--or parts + labor--and how to insure my asset which lives at his property?

Thanks again!

Wow, 18 cards is quite a setup to jump into!

I wouldn't be so sure that there is anything wrong with the setup simply based on the hash rates reported by Coinotron. The hash rates provided by pools are mostly for estimation purposes and are often subject to the kind of wild swings that you describe. This does not necessarily mean that anything is wrong. The hash rate reported by cgminer is always going to be the most accurate, and that's what I would base my judgements upon.

As for 600Kh/s per card... well, that isn't too far off if they're completely stock. At the stock clocks of 950mhz core and 1425mhz memory, the cards should be pulling about 650Kh/s with proper cgminer settings. The 800Kh/s numbers that you see bandied about are outliers -- they don't represent average results (average is probably more like 700Kh/s). Overclocked, the cards should be able to break 700KH/s. It may be possible to see 725Kh/s and beyond with proper cooling... but at that point you'll likely start to lose efficiency as diminishing returns from overclocking set in.

I don't know if this will help at all but here are the most important cgminer settings that I use with my Sapphire 7970s:

Those settings and an overclock to 1019mhz core and 1496mhz memory is all it takes to bring me up to 705KH/s. I overclock using MSI Afterburner software, but it's also possible to set the card clocks using cgminer. The cards are undervolted to 1050mV to lower temperatures and save on power. Without air conditioning, I need to clock my cards down due to heat on hot days. I'm running the Catalyst 13.6 beta drivers with cgminer 3.2 on Windows 7 x64.

Hopefully this helps, good luck!

Hard to go on without more information. Are you sure you are providing enough power to the boxes? Could try connecting each one to a separate outlet (preferably with a surge protector in between). See if that helps.

You may want to find a nerdy/geeky friend to open the boxes and make sure you have the correct parts and that they are in good condition.

Hi All:

I'm a newbie and computer ignorant from a hardware point of view.  I wanted to get into mining and at the same  time give some business to a new local tech company who did a good job for me on other projects--, so I commissioned an 18  GPU card LTC  mining rig.

It is up and running at the builders place, but I notice from the start that the hashrate varies dramatically and from under 200 kh/s to over 1000 ks/s.  (I am monitoring through Coinotron.) 

The average hash rate seems to be about 600 per card, and I thought these cards were supposed to do about 800 on average.  I do not see a pattern of variation of any kind over time.

The builder is aware of the problem, but I don't want to ask too many stupid questions as he is very busy trying to solve many issues.

Just wondering what this may be symptomatic of, and if there is a non technical way of explaining it and suggesting what avenues of trouble shooting to pursue.  (I want to be of some value and it is hard sitting here not knowing what might be going on--the builder is brilliant, but not a great communicator).

I know very little about what else he has used to build the rigs--just that it is 6 machines with 3 cards each.  I could look up the parts I ordered from the invoice.

Thanks in advance for any hints of what may be going on and how serious it is--the difference between 600 and 800 would kill the profit margin.