Bitcoin Forum

Once again....the mods like to close and move this topic....however. It's a question about Bitcoin mining hardware.
It's not about Litecoin, it's not about Chinacoin and it's not about BBQ. It's about Bitcoin god damn. Please don't move this topic to the Altcoin forum, mkey?

My Card: Gigabyte 7970 OC (GV-R797OC-3GD)


CC: 1100
MC: 800

Driver: 9.14
Catalyst: 13.1
CGMine4: 3.1


That give's me about 660 Mhash/s. Now, if I try to higher the core clock , let's say to 1150, my hashrate goes up to 690...but then, after 1 minute or so, my card crashes and I have to reboot. Any idea how to solve this problem?

Thanks.

Every card's different in how much overclock it can take. You're simply pushing yours too far.

So do you think 660 Mhash/s is really the limit of this one? No chance to get some better results? When mining scrypt based coins, I can easily push it up to 720 Khash/s   :-\

Don't set worksize, the default is better. Don't go above intensity 9. Try a different driver. But ultimately, as I said, every card is different.  Make sure you're using --auto-fan to ensure it stays cool enough too.

I've set the fan speed manually to 100%. I'm gonna try the other setting, thx!

Edit: It worked  :D Now i get 690 Mhash/s, thx!

CC: 1150
MC: 800

Driver: 9.14
Catalyst: 13.1
CGMine4: 3.1

Tip:
1040 is magic number for engine OC. Anything over it and you will lower performance from my experience.

That's not true for BTC mining. The higher the engine the better. There is no magic value with normal mining, only scrypt.

I'm only running 3x 7970 gigabyte hd edition and they crank out 2.3-2.5 mh/s. I can post my config for you if you want OP.

7970 @ 715Mhash/s consistent using cgminer 2.10.3 using the last drivers from AMD (13.5 beta) with the following settings:
Fan 85%
Engine:1200
Mem:1050
Intensity:7

Using those settings my 7970's go straight to SICK.  They won't do anything! LOL!


To the OP:  I've got 5 of those cards running, and 2 of them run stable at 690Mh/s, but the other 3 will only run at 660Mh/s stable.  By stable, I mean letting them run undisturbed for weeks at a time 24/7.

My 690Mh/s cards run at 1150 Core / 800 Mem, Intensity 13

My 660Mh/s cards run at 1100 Core / 800 Mem, Intensity 13

All cards are run on Ubuntu 12.10 & cgminer 3.0.1

what brand/model is that card? mine will not do over 660 in a 24/7 setting (1100 mhz is pretty close to the max I can run)

*I should mention, mine are XFX 7970 black edition - reference design blower model, not the DD ones*

Gigabyte HD 7970 GHz Ed. OC 3GB, PCI-E x16 3.0, DP, HDMI

Thanks for speedy response!

it seems like this card is voltage-unlocked, can you confirm? also, what voltage do you run?

On this one I cannot change the voltage. Its always at 1.256v

660 - 680 are fairly typical in my experience.
Thought I can throw some specs, so we have something to compare between cards.
I have:
Sapphire 7970 Ghz edition - goes to 1150/1150 ~ 680 Mhash/s temp 74C
Powercolor PCS+ 7970 mines 1100/1100 ~ 640 Mhash/s temp 80C
settings are: intensity 10, shaders 2048, threads 2, lookup gap 2
TRC and BTC mining
I find out that rising intensity past 10 does not do much - hashes go higher, but they fluctuate a lot and it is ~ 660 in the end
Voltage is locked on both cards and I cannot lower mem less than 950 Mhz, it does not seem to do much for me as well.

Funny thing, I cannot set up those cards to mine together - Sapphire always takes over and it is the card which is recognized under win7 or linux, PCS+ is not seen by the system.

If someone can help with this issue I have a small bounty to offer. Uncle google did not help.
The mobo is GA990XA-UD3

Disable catalyst from the msconfig, after you have turned-on performance mode.
Use afterburner, with all the advanced options selected, (the ones that unlock all the values and extend values beyond normal driver settings.)

Use the "delete profile" trick to get the lowest clocks you can. (open AB, detect cards, lower memory values, do NOT restart the computer like it asks you to do, turn-off AB, delete profiles, restart AB, detect adjusted values as defaults, adjust lower, turn off AB, delete profiles... eg, repeat until you are down to 35-75 for memory. Then SAVE as profile 1. Then manually edit that profile to ensure the new clock is saved, and LOCK the profile by changing the file to a "read only" file.) Now you just start AB and load those settings you want.

First, you need to "lock voltages"... then "set voltage to one of the 4-profiles" (If you have a card with "locked voltage profiles".) For both core and memory. (Memory is limited to 1.5v 1500mv, I believe.)

Second, you need to adjust power consumption to -20 to +20, depending on the power available... (Not sure how may watts you have, or what wattage cooling you have.)

Third, Reduce memory clock to a stable low. (I can go as low as 35 with my low-power profile. But 75-150 is more stable. Higher clocks require higher voltages and available power in wattage from the system. Unstable = underpowered or just mismatched clock-ticks. EG, 35 might fail, 36 might work due to clock-ticks matching.)

Fourth, work on your core clocks... This is SUPER SENSITIVE... Not every "frequency" is valid, or works... Just like the memory. It is power-dependent and also timing-dependent. 1024 might work, 1025 might cause errors, 1026 might work, 1027-1029 might cause errors, 1030-1032 might work... etc...

Bitcoins are ONLY clock-sensitive. Memory is irrelevant, because commands are delivered directly to the card, not buffered in memory. There is no "work" being done in the memory of the card, other than a few holdings, which are less then 300 per second. (Thus a clock of 0.3mhz would be sufficient, if it could go that low.)

If your memory is stable, and you have enough power left, push the core to a comfortable cooling limit that is no greater than 85c. 75-80c is better. 70-75c is the best you should expect with air-cooling, while running at a max.

With air-cooling, and within my wattage range, I can get up to 712MHs, but it needs a rest every few hours. Running at 680MHs, it can run all day, but I give it a rest to cool the other components and let the core cool. Running at 620MHs, I can go over a week, without worry. (Wattage range is within 1500-watts for 6 cards. Unpopulated system consumes 45Watts. Thus, each card draws about 235-watts at the wall. I run about 1400-1455 watts, staying under load with 6x 7970 cards per MoBo. MY values will not do YOU any good. Each card is unique, even by the same manufacture. Also, all my cards have been properly heat-sinked, unlike stock reference designs, which have poor contact.)

To push it over the 712MHs, you need more fans and/or water-cooling. (Both those add more heat and wattage to cool, defeating the purpose and negating any potential gains.)

However, if you expect the bitcoin to rise in value, then the gains MAY be rewards, as earning low-valued coins now, is better than earning a high-valued coin later, at the lower clocks. However, that is a "risk". One which has multiple losses, if you are wrong, and half as may losses if you are right. (Dead cards, wasted power, additional expenditures from overhead.)

Scrypt is memory-intensive... core clock has less to do with scrypt, as much as bandwidth and memory-speed does. (And available system RAM.) It is the opposite of bitcoins, in almost every aspect. You should have two profiles., one with low memory for bitcoins, and one with high memory for litecoins. (BTW, the "effective memory speed" of DDR5 in a 7970, is up to 5000... hint-hint.)

I think you mean 5500MHz.  1375MHz x 4 = 5.5Gbps GDDR5

i have the same card model as your card and i cant pass 1080Mhz, (hashing speed 620Mhash/s Stable **GUIminer**), i can go to 1100 but it will crash within 72hours for sure. The reason is that Gigabyte Hard locked the card voltage to 1.175Volts and there is no way to change that voltage without hardware modification (changing a resistor). There is some threads about flashing the card Bios with the Ghz edition to modify the voltage but that will not change the voltage for real other than the software showing incorrect values. BecareFull DO NOT FLASH YOUR CARD WITH GHZ edition BIOS !!!

Also remember that Gigabyte Ghz edition model: GV-R797TO-3GD is the same card as your card exactly the only difference is the voltage which is set to 1.275, this higher voltage allow more overclocking to 1150Mhz. *YA MARKETING :(*


Although i know Ghz edition can give me higher speed but i didn't buy it because that extra voltage will cause alot of heat issues and instability especially with 4 cards sitting on one closed case. And By the way 660Mhash/s is VERY GOOD !


i Highly Recommend that card for high stability ! ;)

I actually have successfully flashed the GHz version to my card and it worked.  It showed up at 1.256 and everything, and it was stable up to 1200Mhz.  I don't usually use that bios, but I leave a copy of it on my flash drive for whenever I want to use it.

ok guys i have taken the risk and flashed my bios.. it DOES WORK !


speed went up from 1080Mhz to 1170Mhz

hashspeed from 620Mhash/s to 700Mhash/s


for more information read this thread

http://www.overclock.net/t/1294856/cant-increase-voltage-gigabyte-7970-windforce-3x-gv-r797oc-3gd/70


 :)

Please do.

What part of "every card is different" don't you understand? Just because someone gets 1200mhz on their card doesn't mean yours will. You could have good or bad asic quality. You could have really good power circuitry (such as pure reference cards) or really meh power circuitry, which also influences clock speed capabilities. Power quality from your PSU is also a factor; Having low ripple and incoming voltage at 12v (or very slightly higher) is optimum.

I find that "reference but not reference" cards, meaning cards with reference cooler but different color PCB and no AMD logo by the PCI-E connector, clock significantly lower than pure reference, something like 100-150MHz at the same voltage as a pure reference. Speaking from experience with 14 7970's.

Every card is different if you want to read asic quality read it with the program gpu-z. If your 60%-70% which I would guess you probably are you won't get 700 megahash. Sorry to ruin it for you. IIRC correctly you need 75-80% to hit over 700 megahash reliably

Which bios did you use for flashing?

I got on my sapphire refernce card 65% asic quality and it still gets 700MH/s. By default it uses 1.175V, need to get 1.181 to be stable at 1174 MHz on core. Memory -160Mhz and it's mining happy.