Just bought a "freak" 7950 (LTC)

[mxc0bbn]

~685Kh/s average at this time.
In the pic GPU0 is indeed a 7950 (oc'd of course, but they all are)...Gigabyte 7950 windforce.  The other 3 are Sapphire 7950s.




I got greedy and tried to push it as far as it would go   ...I got it to go to 696kh/s, but it was too much as I started to get HW errrors.  The hardest I've been able to push the Sapphires are in the ~635-645kh/s range.  I think I'm going to buy Gigabytes from now on  

[metalh47k]

I highly recommend Gigabyte 7950s.

My work mate was able to push 665MH/s out of his 7950. imgur.com/a/GHFQy

1165 Core 1050 Mem Stock Voltage. Air Cooled.

http://imgur.com/a/GHFQy

[computerparts]

Congratulations you have won the silicon lottery. But it looks to me like you're still getting HW errors in the first pic.

[mxc0bbn]

Congratulations you have won the silicon lottery. But it looks to me like you're still getting HW errors in the first pic.

Yes, well...ahem    once I thought I had the GB7950 stable at around ~682 I tried to make some adjustments to the Sapphire 7950 in slot 3   

And it threw up all over me    so I had to back off that one...

but UPDATE on the experiment...

I had to back off the settings on the GB7950 as well because it was becoming unstable after about an hour...I've made some changes and it is now mining stably (I hope) at around 670Kh/s...

All in all that is still not bad...the LTC hardware comparison guide has the highest 7950 at 684, but at 92C degrees 

Even at 685 mine never went above 79...

Right now it's around 77C @ ~670Kh/s

[MrThePlague]

How important is the Utility? I generally get 615 kh, but my Utility is 4x of yours. Is it worth pushing the hash up and dropping Utility?

[ssateneth]

Too bad you are losing more money than you are gaining by using an OVERVOLTED 7950.

[ronaldinho_07]

Giga 7950 wf3x,the result from the one who is member of vozforums

1140/1250 this clock generated ~ 696Khash/s

[ocmoho]

yeah, i thought these were pretty normal hashrates for these cards.
Both my sapphire 4Ls are running ~680.
This is my home rig with 4L 7950, and 7870ghz:

BTW its watercooled.(48°C is the correct temp)

[thef]

I have two 7950s that can do 690+ kh/s but they have to be overclocked to 1200/1750.

[hendo420]

I have two 7950s that can do 690+ kh/s but they have to be overclocked to 1200/1750.

I have 3x sapphire 7950s that do 690kh/s at 1175/1600 1.2v
I'm working on getting the voltage down and keeping the hash rate over 650kh/s.

Why do all the 7950s i get come stock 1.25v, there is no need for that voltage. At stock clocks it could do 1.0-0.9v. lol

[sikman]

nice work, what thread-concurrency are you using? and what drivers and sdk version as well??

[anderl]

I recommend reapplying the thermal compound on the gpus.  these devices are mass produced and thermal compound application is not uniform.  I mostly buy gigabytes and the temperature variation between the cards can be huge.  it helps performance a  bit, I can get about 10% out of the cards that way.  other than that there is the asic chip quality.  sometimes you get good gpus sometimes you get bad ones.  luck of the draw.

[p00chie]

I have two 7950s that can do 690+ kh/s but they have to be overclocked to 1200/1750.

I have 3x sapphire 7950s that do 690kh/s at 1175/1600 1.2v
I'm working on getting the voltage down and keeping the hash rate over 650kh/s.

Why do all the 7950s i get come stock 1.25v, there is no need for that voltage. At stock clocks it could do 1.0-0.9v. lol

maybe they want the cards to crash faster
i think these settings are only possible with cgminer or bitcoin/litecoin mining. if you would try it in games it would crash. i had the same issues with my 7970. there was no way my cgminer settings would work in games. so in the first thought these cards are made for games

[jdebunt]

was looking at 7950's, so this sure is a thread with good information about which brand to buy

[hendo420]

I have two 7950s that can do 690+ kh/s but they have to be overclocked to 1200/1750.

I have 3x sapphire 7950s that do 690kh/s at 1175/1600 1.2v
I'm working on getting the voltage down and keeping the hash rate over 650kh/s.

Why do all the 7950s i get come stock 1.25v, there is no need for that voltage. At stock clocks it could do 1.0-0.9v. lol

maybe they want the cards to crash faster
i think these settings are only possible with cgminer or bitcoin/litecoin mining. if you would try it in games it would crash. i had the same issues with my 7970. there was no way my cgminer settings would work in games. so in the first thought these cards are made for games

I can game on them at those clock/voltage settings. The cards barley get warm gaming too. Playing BF3 and Black Ops 2. I have a feeling the voltage is so high stock is to compensate for the inevitability of a shit chip on a video card. It means less reject cards. Even if it has a shit gpu it will still run at the higher voltage.

[glendall]

These cards are the best thing going Imho. Mine pumped out 640 hashes with little to no work whereas my Sapphires are rarely able to go over 600 with a lot of tweaking.

Been intending to flash the roms' of the sapphires but haven't got around to it...