MultiGPU mining - constant crashes

[PulsedMedia]

So i acquired today for testing & fun 2x6770s (same price as 5770).

Well, i dont' got the crossfire bridge, so they are running separately now, i do have 1 monitor connected to each card.

Problem is: IF i try to mine with both vid cards at the sametime it most often causes a crash.
Using via GUIminer i can start them running, but as soon as either one stops it's a crash again.

I've tried phoenix, guiminer and puddinpop's (which worked the worst).

Running win7 64bit. Not a dedicated mining rig, a workstation i decided to finally get some GPU power on as well

Thanks!

[Oldminer]

Two words:

Power supply

[PulsedMedia]

Two words:

Power supply

Nope, offers plenty of power for 2x6770 (550W corsair)

[Oldminer]

Two words:

Power supply

Nope, offers plenty of power for 2x6770 (550W corsair)

A 600W is recommended according to this chart http://www.amd.com/us/products/desktop/graphics/amd-radeon-hd-6000/hd-6770/Pages/amd-radeon-hd-6770-overview.aspx#3

[PulsedMedia]

Two words:

Power supply

Nope, offers plenty of power for 2x6770 (550W corsair)

A 600W is recommended according to this chart http://www.amd.com/us/products/desktop/graphics/amd-radeon-hd-6000/hd-6770/Pages/amd-radeon-hd-6770-overview.aspx#3

Depends upon the quality of the PSU. Weak 600W will be same as 300W quality.
Weak: All is counted as total. Corsair, Enermax atleast count ONLY 12V rail outputs to the marketed total.

2x6770 sucks about 220W, my CPU (even tho it's extreme series) prob around 130W, and rest prob 50W. and GPUs and rest don't enjoy even solely 12V.

In any case, they are now running stable on the *same* system, in crossfire. Kind of, still reports 2 adapters, yet i got crossfire enabled. Whatever, is not crashing anymore. (Not needed for gaming). Next week 2x5970 arrives anyway and got to upgrade PSU, hopefully some store will have 1kW enermax in stock


Oh and quality differs: 550W cheapo PSU was not able to power up a system which a really old Enermax 350W was happy to powerup I think that system required something like 450W and the really old, too small Enermax didn't have problems with that

[freeman725]

Two words:

Power supply

Nope, offers plenty of power for 2x6770 (550W corsair)

A 600W is recommended according to this chart http://www.amd.com/us/products/desktop/graphics/amd-radeon-hd-6000/hd-6770/Pages/amd-radeon-hd-6770-overview.aspx#3

Depends upon the quality of the PSU. Weak 600W will be same as 300W quality.
Weak: All is counted as total. Corsair, Enermax atleast count ONLY 12V rail outputs to the marketed total.

2x6770 sucks about 220W, my CPU (even tho it's extreme series) prob around 130W, and rest prob 50W. and GPUs and rest don't enjoy even solely 12V.

In any case, they are now running stable on the *same* system, in crossfire. Kind of, still reports 2 adapters, yet i got crossfire enabled. Whatever, is not crashing anymore. (Not needed for gaming). Next week 2x5970 arrives anyway and got to upgrade PSU, hopefully some store will have 1kW enermax in stock


Oh and quality differs: 550W cheapo PSU was not able to power up a system which a really old Enermax 350W was happy to powerup I think that system required something like 450W and the really old, too small Enermax didn't have problems with that

Running in crossfire will cut your hash rate by 15 to 30%. Run both cards independently and make sure you either have a second monitor, or a dummy plug ooked to the second card.

[PulsedMedia]

Two words:

Power supply

Nope, offers plenty of power for 2x6770 (550W corsair)

A 600W is recommended according to this chart http://www.amd.com/us/products/desktop/graphics/amd-radeon-hd-6000/hd-6770/Pages/amd-radeon-hd-6770-overview.aspx#3

Depends upon the quality of the PSU. Weak 600W will be same as 300W quality.
Weak: All is counted as total. Corsair, Enermax atleast count ONLY 12V rail outputs to the marketed total.

2x6770 sucks about 220W, my CPU (even tho it's extreme series) prob around 130W, and rest prob 50W. and GPUs and rest don't enjoy even solely 12V.

In any case, they are now running stable on the *same* system, in crossfire. Kind of, still reports 2 adapters, yet i got crossfire enabled. Whatever, is not crashing anymore. (Not needed for gaming). Next week 2x5970 arrives anyway and got to upgrade PSU, hopefully some store will have 1kW enermax in stock


Oh and quality differs: 550W cheapo PSU was not able to power up a system which a really old Enermax 350W was happy to powerup I think that system required something like 450W and the really old, too small Enermax didn't have problems with that

Running in crossfire will cut your hash rate by 15 to 30%. Run both cards independently and make sure you either have a second monitor, or a dummy plug ooked to the second card.

I'm actually doing the exactly same 180-185M max per card ~stock clock. (stock 850, running 860)
Currently aggression 4 and aggression 8 -> 78 and 180.
Shutting down youtube brought adapter 0 (main monitor) to 156 average (154-157 bouncing)

Still need to checkup a lot on overclocking ATIs, first ATI GPUs i've owned in.... Like 8+ years. I've been NVidia all the way until recently my last 8800Ultra burned.

[Keichtech]

Are you over clocking your cards?
If you are and they are set to high I know it can cause a crash, happened to me.

[goozman96]

Just in case:
They've got sufficient cooling, right?

[PulsedMedia]

Same thing happened with stock clocks, and cooling is sufficient.

Update: Since updating my system, adding crossfire bridge seemed to solve the constant crashes!
I can now freely stop & restart the mines, both GPUs work fine etc. no more crashes. So it seems the reason was you need to add the crossfire bridge oO;