7970 vs 7950 vs 2x6950 for BITCOIN mining?

[thilanliyan]

^Yeah I find that about 310 MHz on the memory gets me the best hashrate to power ratio.

 

[WhoBeDaPlaya]

my hashrate starts falling off if I go below 300. what hash rates do you get with your 6950s?

On unmodded 6950 1GBs (RAM 200MHz, Core 840MHz), I get about 340MH/s. Granted, this is with much older Cats (11.6 IINM).

My 6950 @ 6970 (no OC, RAM 750MHz) gets about 380MH/s.

 

[RussianSensation]

On unmodded 6950 1GBs (RAM 200MHz, Core 840MHz), I get about 340MH/s. Granted, this is with much older Cats (11.6 IINM).

My 6950 @ 6970 (no OC, RAM 750MHz) gets about 380MH/s.

With what program is that? I used GUIMiner (with flags -v -w 128 -f1) and got 390MH/sec on an unlocked 6950 @ 880mhz GPU with memory at 760mhz. You should upgrade to latest drivers. I remember one of them gave me a nice 10-20 MH/sec increase. Maybe it was 12.2 or 12.3. I don't remember but there was definitely a boost with one of them. Also grab SDK Stream version 2.6 or later.

 

[WhoBeDaPlaya]

With what program is that? I used GUIMiner (with flags -v -w 128 -f1) and got 390MH/sec on an unlocked 6950 @ 880mhz GPU with memory at 760mhz. You should upgrade to latest drivers. I remember one of them gave me a nice 10-20 MH/sec increase. Maybe it was 12.2 or 12.3. I don't remember but there was definitely a boost with one of them. Also grab SDK Stream version 2.6 or later.

Older cgiminer (1.5.5) and Cats (11.6). Setup them up last summer and haven't bothered upgrading them. It's also a little difficult to do since most of my miners are about 1,000 miles away

 

[jmseeley]

hi im new to mining and bitcoin but here's what im doing.

7970 with catalyst 12.6 Beta(made a huge difference) and current sdk running at 742 mh/s o/c at 1250 gpu memory at factory settings running 69 to 70 degrees

 

[RussianSensation]

Welcome to AT jmseeley,

Those are great speeds. You can drop the memory to 685mhz or so by enabling Unofficial MSI Afterburner overclocking. The performance hit should be small.

See this post on how to edit the MSIAfterburner.cfg file in NotePad: http://forums.anandtech.com/showpost.php?p=33722469&postcount=2

Put "2" in the UnofficialOverclockingMode=2

 

[OVerLoRDI]

If you pay a fixed amount for electricity... Oh man I would go CRAZY! Oh wait I did last year during bitcoin's heyday.

If you don't pay for electricity and if heat isn't a concern, get a 7970 and overclock like crazy.