Bitcoin Forum

my setup is a gigabyte hd 6950 running gpu @ 945 memory @ 750... i was getting 390 to 450 mhash. i was gaming and experienced a crash. now no matteer what i do i can only get around 300 even overclocked and at stock i only get around 292 mhash. stock this card should get like 350.

im using phoenix miner with the command

phoenix.exe -u http://user.user.pass@pool.ABCPool.co:8332/ -k phatk2 -q 2 DEVICE=0 VECTORS AGGRESSION=10 BFI_INT



Im on windows 7 x64, im running latest catalyst drivers from ati, and amd app sdk 2.5.

I did a fresh install on seperate hard drive with same drivers and settings and i get the same numbers.... is something wrong wtih my card??? this is so nuts, card is only 3 months old.


i have scanned with hitman/malwarebytes/combofix/tdss killer. i dont seem to have any infection and the fact i tested this on a clean install really blows my mind. any help on why my card is running 100 mhashs slower than it was would be greatly appreciated.

What symptoms were the "crash" - i.e. did you system hard-freeze? Display corruption? There's a decent chance it overheated. check the fans to clear them of dust and see if you ATI software will allow you to alter the fan speed. Possible fan dead...

what happenned was i accidently left my settings to bitcoin mining overclock settings and ran battlefield 3, yes it was a hard crash.

i have blown out the fans and heatsink the fans are all spinning i have tried manually making them go @ 100 percent. same thing.

ok just rechecked. there was definitely a sata cable stuck in the first fan... cant believe i overlooked that


i unstalled drivers... and reinstalled but im still getting the same @ stock 290 mhash.... i removed EVERYTHING AMD, even the profile under app data. i just want my old speeds back ...


i did have a fan stuck for maybe 1 month and didnt realize it. i deleted and reinstalled drivers..... what else can i do to fix this?

So you have unlocked shaders? Which pool do you use? And, is that where you are getting hashrate from?
450Mh/s is impossible with a stock (no mod) 6950. If you get your hashrate from the pool stats page, that is an estimation, and will vary.

Does your card run at 99%?

abcpool.co is what  i use, i didnt mean 450, i dont know why i typed that i meant 350-400 mhash.   the numbber is from the window phoenix is running in. i know that the pool reports higher than my actual rate, but im talking about whats reported locally.

i still cant get back to over 315. stock this card runs the gpu @ 870. it used to get 350 mhash not overclocked what can i do? or is it rma time?

yes my card is @ 99 percent, its runninnng @ 310 mhash clocked at 930 mhz.... wtf is going on stock this card got 350, i was able to get 390 with card clocked @ 930. plz this really sucks

try a different miner, I use cgminer.exe
with -g 10 and intensity 9

I think i have the same 1 GB gigabyte 6950/OC running @ 940 Mhz getting ~388 Mhash

please let me know if you have good news

This is your problem, drivers 11.12 and 12.1 include a new sdk that overwrites the old one and doesn't uninstall, and causes a performance drop. Follow the instructions here: https://bitcointalk.org/index.php?topic=54693.msg651989#msg651989

what are mhash sorry i am a noob -___-
~andy ^_^

This refers to mega or million hashes per second, a measure of how fast miners (who support Bitcoin and earn income by computing the puzzle used in generating Bitcoin transaction blocks) are able to brute-force search SHA256 cryptographic hashes of transaction blocks for one that meets the high-difficulty challenge.

As a frame of reference currently (difficulty changes periodically to adapt to amount of global hashing power) it requires on average ~5 quadrillion (5000 trillion) hashes to solve a block. 

TYVM!!! back @ 389 mhash o'c .


thank you thank you... the post had a zip file with the old SDK files in it, it took 10 seconds to replace.