Bitcoin Forum

I was looking at getting a Gigabyte GV-R795WF3-3GD  hd 7950 to play with mining. I read a recent review where they stated that it is now voltage locked via hardware- you cant get past the voltage lock by flashing to the F43 bios (from FZ1. True, or did this guy not know what he was talking about?

Forgot to mention, he stated that it was locked at 1.25 volts.

The Gigabytes are indeed voltage locked now.

These are the 7950s I have found that still seem to have the voltage unlocked.

PowerColor AX7950 3GBD5-2DHV4:

SAPPHIRE 100352-3L:

MSI R7950 Twin Frozr 3GD5/OC:

Is it really all that bad to be locked though? - Some people have said they get 650-700 K/Hs all day long from their Gigabyte 7950. ....or was that the previous unlocked versions they were doing that with?

They did used to be unlocked so not sure. I can tell you that voltage unlocked is nice, I mine LTC which is picky about memory speed but @ 885 core and 1375 memory I get the best hash rates and was able to lower my voltage from 1175 to 1145 which actually made like an 8C difference on temps.

Is 7950 the most cost effective, or just the most powerful chip that is still considered efficient?  There seems to be huge piles of conflicting data about performance compared to efficiency.

I don't know why I didn't tell you but the video card I am talking about is a 6950 and it does 432 Kh/s at the settings in my previous post. I can't really tell you if 7950s are the best because I don't own one. It does seem from all the reading I do that at least 80% of the new rigs being built seem to include the 7970. I personally would like to build a rig with the Gigabyte 990FXA-UD7 and 4 x Msi or Sapphire reference 7970s so I don't have to use any riser cables.

At this point all I can do is be jealous.  :-p  I'm running on GTX570's from my gaming rig.  Don't have a dedicated mining machine...  I get about 180Kh each, but it's such a joke compared to AMD cards.

7970 is faster than 7950, but after overclocking the 7950 can get pretty close if not faster.  This coupled with the fact that it is 100 dollars cheaper and uses 50w less power makes it the go to LTC mining card.

Yeah I can't believe the difference in hash rates between the green and red team. I think it is interesting that the 680 and the 7970 trade blows across lots of games but the difference in hashing is unbelievable. I luckily was never a fan of the green team anyway and have always used AMD. I think my first AMD card was a 9200 Pro lol.

Nice setup

I tend to be brand agnostic, but the drastic hashing ability differences may start to bias my choices a bit.  Doesn't matter so much for SHA256, since ASICs will own that sooner or later...  but scrypt coins seem to be the smart way forward, and having better tools on hand couldn't hurt in that eventuality.

 I have either the 7950 or the 7970, and I assure you they're both unlocked. Sounds to me like the people were mining with their CPU, not their GPU, because I get about 510 MH/s without flags.

I have a locked gigabyte and I do 630kh/s at 1050/1450 +10% power at 70ish c

Are you positive you meant KH/s and not MH/s? Mining at a speed as low as that is not worth anything, seriously. If you really are mining that low, you're using your CPU, not your GPU.

You should be getting *at least* 400-500 MH/s

He is mining LTC not BTC.

Oh dear, my mistake. Apologies.

just see!

Im running HIS at 1100mV, +20 power, 1050 Core, 1500 mem.  Pulling about 600 khash per card.  Not sure if some peoples numbers are inflated or not.  Seems to be about the best I can get.  Voltage is adj though.

Yes, I forgot to say that I was referring to LTC mining. Thanks. I have a Gigabyte on order, and will see what I can do with it. If I can get it to do 650 khs or better- then I will order 18 more  :o

I have two Gigabyte 7970's and they'll do 700+ all day on 18 Intensity mining LTC. One of them runs WAY cooler, 71 C vs 81-83 C.

Haven't had a chance to toy around with them to try to get the temps down yet.

~richgene

the gigabyte can still be flashed to a diffent bios with defualt 1.09 vddc so not so bad

Hi, I bought gigabyte 7950 recently, can not tweak voltage under linux ... going to try on win soon, but overclocking works fine - fan 100% (quite noisy), temp 59 C, voltage 1.25V, engine clock 1180 MHz, mem clock 1030MHz, Bitcoin mining around 615Mhash/sec with DiabloMiner