Bitcoin Forum

Hi all,

Just been toying with a new mining/opencl rig. Running 6x7970s via pci risers on a 1500w gold PSU. Not drawing close to that according to the killawatt when it BSODs.

Every time I try to run up 5 or 6 cards in cgminer I get an almost immediate BSOD.

Running 12.4 catalyst drivers

Try newer drivers or 11.12

Thanks. Are 11.12 drivers particularly good or known to work with 5-6 cards?

I don't remember which 12.x are okay, but when 12.1 came out I got BSODs after adding 5th card, switched back to 11.12 and it was fine.
But I only have HD5xxx and HD6xxx, if you have HD7xxx series search if 11.12 will work fine / best.

Unfortunately 11.12 dont seem to work with 7970's :(

You guys are all talking about drivers and PSU limitation and such, but have you considered it's the motherboard? Keep in mind that every PCI-e slot draws about 25w, even if you have the external GPU power plugged into each card. if you're cramming 6 cards on the motherboard, that's already 150w of power being shoved through the motherboard just for the video cards alone. This will definitely throw off stability. That's why the cablesaurus sells extension cables with power molex plugs to prevent the PCI-e slots from drawing power straight through the motherboard.

11.12 from the website do not work with 7970, but the RC 11.12 that come on most driver discs with 7970's do and they are the ones I stick with as well

Thanks! I managed to find some on the AMD site.

I can now see 5 cards working in device manager, but the 6th card still has an exclamation point - if I remove any one card the device mgr problem goes.

I tried running the main card on a 1x riser instead of the 16x as well with no luck.

Seems like I've gone from a hard limit of 4 to 5.

Any further ideas?

What OS are you using? Try BAMT.

Windows - I want to use this rig for OpenCL as well as bitcoin if I can.

Had no luck with BAMT (https://bitcointalk.org/index.php?topic=65915.msg1177246#msg1177246)

In addition to being capped at 5 cards, I am now finding that they are all only running at 80% of the clock set by AB which is highly irritating as the overall mhash is identical to 4 cards :<

What motherboard are you using?

Asrock H61DEL

Sounds like the same issue this guy (https://bitcointalk.org/index.php?topic=97154.0) ran into.  Turns out that one of the PCIe x1 slots gets disabled when an adjacent one is occupied.  Try asking ASRock whether or not all slots can be filled.

When are you expecting to get back your ROI?

in how many days?

I am not and was not expecting a complete ROI per rig from BTC revenue alone.

My model factors in a few things
1) Power cost
2) Depreciation cost
3) BTC revenue
4) Selling hardware when net mining revenue after power = depreciation cost
5) Continued usage of one rig for OpenCL work after selling the other

i.e. I never expected to make a good ROI, merely to have two rigs pay for as much of one rig as possible so I can keep using it for .

As a unfactored in bonus I am using coinlab to extend my rig life - not sure how well this will work yet so its not included in the model.

The way I am going so far with all these roadblocks is not making a good case for continuing. The time spent alone means the whole thing has been a bit of a white elephant. Probably the only reason I am persisting is because tinkering is kind of entertaining rather than being an efficient use of my time.

try disabling unused motherboard devices in the bios if you have not done so; front USB, audio, firewire, etc.

powered risers may also help.

Disabled everything other than USB and sata with no luck.

Must be either a driver or motherboard issue I think.

I still couldn't work out why the cards run slow when 5 cards are working, their clock speed oscillates around 700mhz instead of  925 MHz under load. The 11.12 drivers seem to misreport utilization in after burner on 5 cards.

When running 4 cards on 12.8 they're rock solid on 925.

http://www2.ati.com/drivers/hotfix/radeon_7900_series/amd_radeon_hd7900_win7_64.exe

**Win7 x64 ONLY

install the driver and do not install APP

download the 12.4 and just install APP

i'm hope it can help