Sapphire Radeon HD 7970 good for mining?

[maxmint]

I'm completely new to mining but would like to start a little rig, just to get my feet wet.
I could buy two Sapphire Radeon HD 7970 cards for $325 each – would these be suitable for mining bitcoins / litecoins?

I know that miners are talking about 7970s all the time but I'm not sure if this particular brand would be good.

Thanks for your help!

[-ck]

Assuming you are talking about the stock reference design, most of the cgminer GPU development of the last year was done with these cards. They are excellent. They vary in quality of course and my worst produced ~685MH and the best ~720MH on BTC. The best LTC miner produced ~745KH.

[btcminer021]

I could buy two Sapphire Radeon HD 7970 cards for $325 each

Link?

[mtbitcoin]

The cards are great for Litecoin mining. I get around 750-760KH per card with CGminer.

Cheers

[Anvi]

I can't get proper settings with my Sapphire 7970 (reference) and topping out at 710kHash, but different cards are never really the same when it comes to litecoin mining... My HIS 7970 IceQ2 gets me 804 kHash at 1147/1825MHz Or 720kHash at 1031/1250MHz, which is a lot more efficient.

[maxmint]

Thanks for your answers. I guess I'm gonna get one to mine some LTC.

[TheFuneral]

Assuming you are talking about the stock reference design, most of the cgminer GPU development of the last year was done with these cards. They are excellent. They vary in quality of course and my worst produced ~685MH and the best ~720MH on BTC. The best LTC miner produced ~745KH.

Would you mind explaining how you get 685-720? I can't seem to get them past 470s. I tried your guide https://bitcointalk.org/index.php?topic=28402.msg1635964#msg1635964 , but when i run cgminer with --scrypt and -i 13 and no thread-currency I get this error.

Error -5: Enqueueing kernel onto command que clEngqueueNDRangeKernel

After googling I'm lead to believe it's this
https://forum.litecoin.net/index.php?topic=34.10;wap2

but I have no thread-currency specified.

[-ck]

7x series card+motherboard combos either fall into two camps: Those that like and work with high thread concurrencies and those that don't. If it fails on startup without specifying a thread concurrency, then you have a hardware combo from the latter group and either you'll need to increase your system RAM, or if that's already enough, you will have to run them at a low concurrency (usually 8192), low intensity (usually 13) and more gpu threads (-g 2).

[TheFuneral]

7x series card+motherboard combos either fall into two camps: Those that like and work with high thread concurrencies and those that don't. If it fails on startup without specifying a thread concurrency, then you have a hardware combo from the latter group and either you'll need to increase your system RAM, or if that's already enough, you will have to run them at a low concurrency (usually 8192), low intensity (usually 13) and more gpu threads (-g 2).

Thank you very much for your fast input.

my setup seems to behave in the group of where it doesn't work with high thread concurrencies. Since this is the case how much system RAM would you recommend I increase to hit the 750s mark with my cards?

I currently have this mobo;
http://www.amazon.com/gp/product/B005POPRG8/ref=oh_details_o04_s00_i02?ie=UTF8&psc=1
with ONE of this ram;
http://www.amazon.com/gp/product/B003ZDJ42O/ref=oh_details_o04_s00_i01?ie=UTF8&psc=1
I also have four of these cards;
http://www.amazon.com/gp/product/B009B6Y01Y/ref=oh_details_o04_s01_i00?ie=UTF8&psc=1
if that helps determine the proper system RAM amount.

[big pete]

i have a saphire 7970 hd oc

it will sit all day 24/7 on around 660mh ... you can get it up to around 700-710 or so but it will overheat in a few seconds, or at 685mh it will overheat in around 2-3 hours.

for $325 seems like a good deal, its not a bad thing, ive not tryed it on litecoin yet, ive put my other cards on LTC as my days of gpu mining btc are over but hadnt got around to this one yet, but i might give it a go today ... let you know what i come up with

happy to give u my oc settings if you like

[BitshireHashaway]

These would be great for mining. Would you mind providing me a link so I can get some:)

[TheFuneral]

i have a saphire 7970 hd oc

it will sit all day 24/7 on around 660mh ... you can get it up to around 700-710 or so but it will overheat in a few seconds, or at 685mh it will overheat in around 2-3 hours.

for $325 seems like a good deal, its not a bad thing, ive not tryed it on litecoin yet, ive put my other cards on LTC as my days of gpu mining btc are over but hadnt got around to this one yet, but i might give it a go today ... let you know what i come up with

happy to give u my oc settings if you like

Hey Pete,

I'd lover to hear your settings. My cards are no where close to 660.
What is your core/memory clock speeds along with voltages. What are your cgminer settings?

I'm considering flashing the bios as talked about here ( https://bitcointalk.org/index.php?topic=200777 ), but I'm not quite convinced why that would fix my slower speeds.

[ISAWHIM]

No need to flash anything... That will just brick most cards.

AB and catalyst is all you need. (But you have to unlock them by agreeing to the disclaimer, and do an initial "sorta-hack" to get the extended ranges to function. Involves just deleting the profiles and restarting AB without "shutting down" the PC.)

Voltages are NOT "fixed", they are "locked". Locked = can be changed if unlocked, but have a limited range and steps that are "stable". (This is per-card, as it is a hardware limitation thing.)

You want to run at the fastest core-clocks, for the lowest voltage. UNLESS you have water-cooling and unlimited power. Then you can go into the higher/stable voltages and OC clocks.

EG, my standard rigs are roughly this...
CoreVolts: 1100mv
MemVolts: 1500mv
PowerLimit: +0 (-20 on special occasions)
CoreClock: 1100MHz
MemClock: 150Mhz

That results in about 215watts per card at the wall, at 640MHs. (About 2.98 Hashes per watt) All cards air-cooled and under 75c, as low as 65c. (FYI the temp sensors are crap on these cards. Uncalibrated and not true to actual temps. Actual temps are about 69c on all cards.) Fans inappropriately running from 75%-50%, due to false temp readings from the cards. 80% for all, temps stay as low as 72c-58c.

My limiting factor is wattage. With more watts, I would push the clocks up to 1200, with a 1150 core volt and a 300 memclock, taking them easily to 690MHs, where cooling becomes a concern. Water-cooling just isn't worth the added cost. It is cheaper to get more cards and build another rig, with standard power and cooling.

Best hashes per watt that I have ever had, was only stable for a day of operation, at 3.33 hashes per watt. Running 640MHs @ 192watts. (1080corevolt, 1120coreclock, 1500memvolts, 75memclock, -10% power, fans running 70%.) One temperamental card destabilized the bunch.

[TheFuneral]

No need to flash anything... That will just brick most cards.

AB and catalyst is all you need. (But you have to unlock them by agreeing to the disclaimer, and do an initial "sorta-hack" to get the extended ranges to function. Involves just deleting the profiles and restarting AB without "shutting down" the PC.)

Voltages are NOT "fixed", they are "locked". Locked = can be changed if unlocked, but have a limited range and steps that are "stable". (This is per-card, as it is a hardware limitation thing.)

You want to run at the fastest core-clocks, for the lowest voltage. UNLESS you have water-cooling and unlimited power. Then you can go into the higher/stable voltages and OC clocks.

EG, my standard rigs are roughly this...
CoreVolts: 1100mv
MemVolts: 1500mv
PowerLimit: +0 (-20 on special occasions)
CoreClock: 1100MHz
MemClock: 150Mhz

That results in about 215watts per card at the wall, at 640MHs. (About 2.98 Hashes per watt) All cards air-cooled and under 75c, as low as 65c. (FYI the temp sensors are crap on these cards. Uncalibrated and not true to actual temps. Actual temps are about 69c on all cards.) Fans inappropriately running from 75%-50%, due to false temp readings from the cards. 80% for all, temps stay as low as 72c-58c.

My limiting factor is wattage. With more watts, I would push the clocks up to 1200, with a 1150 core volt and a 300 memclock, taking them easily to 690MHs, where cooling becomes a concern. Water-cooling just isn't worth the added cost. It is cheaper to get more cards and build another rig, with standard power and cooling.

Best hashes per watt that I have ever had, was only stable for a day of operation, at 3.33 hashes per watt. Running 640MHs @ 192watts. (1080corevolt, 1120coreclock, 1500memvolts, 75memclock, -10% power, fans running 70%.) One temperamental card destabilized the bunch.

What do you mean by initial sorta-hack to get extended ranges? What ranges am I looking for? What does that do?

It sounds like you can't get the cards up to the 700 range either?

I'll try your settings tonight and see how my cards react. I don't have limited wattage luckily in my case so undervolting them is a last priority. I'm trying to get the hashes up first before I worry about that.

Do you just set your fans at a fixed rate instead of using the cgminer automatic fan feature?

why would flashing them be a bad idea or not needed if my cards won't preform on scrypt?

[btcminer021]

I finally got two 7970s stable at 1100/950 (core/mem) at 1.2V pulling about 660Mh/s each at 70C fans auto (70%?) 99.63% accepted shares and no HW errors.

[snowcrashed]

I'd really love to know where the OP is getting 7970's for $325

[btcminer021]

I finally got two 7970s stable at 1100/950 (core/mem) at 1.2V pulling about 660Mh/s each at 70C fans auto (70%?) 99.63% accepted shares and no HW errors.

You can lower memory all the way to 50 MHz (on Windows with afterburner) without affecting hash rate.  Your fans will drop to 50-55%

That seems a little TOO low, no? Maybe 800, 600MHz at the lowest? I'm using the Sapphire TRIXX utility and want to stick with that.