Got two 7970s in April, and 2 more last week for a milk rate rig. Also have 2x 5870s for gaming/mining.

Seeing it now as a self funding hobby with gaming perks, maybe pay for a new gaming rig if lucky.

Can't see it being more than that due to asics, like others posted escape hatch is ltc or ebaying the cards.

Ordered 2 cables from cryptocables.com a week or two ago, they have been running great.
Just ordered 2 more.

Payments via paypal or bitcoin by Bitpay. Shipping is 2day USPS $5.

Whoever runs it seems nice enough in emails, prompt with communication and shipping for of both orders.

tldr;
a++ would order again.

Rebate has a 1 limit unless you use alternate mailing address, etc.

It's in the fine print.

I have a 3-card setup, and due to heat issues, tried to use a unpowered riser on the middle card (5870). It booted, but always forced a reboot when mining. Tried a 2nd riser cable, same deal. Then tried a DIY Molex mod, with both cables. Was able to mine for about a few hours, then the card would crash. Trying again soon with a factory-made powered riser.

Anyway, not everyone has the technical expertise or tools to test PCB amps and stuff. So disagreeing with the thread title... out of an abundance of caution, its probably easier just to use a powered riser.

Yeah, what is your setup, and brand/model of mobo, video card, power supplies?

File or Milk Crates - https://bitcointalk.org/index.php?topic=66432.0

Use PCI-E riser extension cables (powered).

Are those powered risers ones you modded yourself, to sell? Or did they come that way?

Have a 3x PCI-E slots, needed to move the middle GPU out for airflow. Tried using an unpowered riser cable at first, and would have voltage drops that led to hard reboots while mining.

Tried modding a molex to the riser, works fine for a few hours, then the card goes SICK/DEAD. Rebooting doesn't help much, it goes sick/dead faster. Removing and adding back the riser-cable to the card seems to get it going again, but then the same problem comes back after a few hours.

tl;dr
Think of BTC miners as a jury pool. If a single entity controls 50% of the pool, they can sway the jury for bad things.
It's better for everyone involved if the 50% mark never comes to pass.

I have 2x7970's and a 5870. Seemed to lose about 10-20mh/s, plus weird graphic glitches. Monitors being randomly redrawing the entire screen etc.

Went back to 13.1.

http://www.guru3d.com/files_details/amd_catalyst_13_4_whql_download.html

Just came out! At work now, so can't try em out. Post if you have any hash performance results.

I have some XFX7970's, using 13.1 drivers. Had to clock it up to 1160+ to hit 700mh/s. Mine has mostly been stable around 1140mhz.

Could never underclock memory below 1300 either.

Make sure there doesn't exist a cgminer.conf file, then run cgminer.exe directly. It should load with auto settings.

If that doesn't work then Idk sorry :|

Ohhh man a milk crate. Why didn't I think of that LOL.

Got pictures? Also, where did you get your riser cables from...I just ordered some from DealExtreme and hoping they turn out okay.

Are you using a cgminer.conf file? You might need to re-create it from scratch

If you changed slots, it might also affect your OC settings.

Unless you have special settings within the game, it should use the GPU that is connected to your monitor that displays the game.
Works the same with videos, etc.

13.1 AMD Drivers, MSI-AB unlocks

CGMiner, Diablo, Intensity 10, other hash settings default

All Cards are at Stock Voltages

690-700Mh/s, 74C
XFX 7970 (FX-797A-TDFC Rev5, brown box)
OC: 1160mhz GPU Core, 1300mhz Memory
Default: 1000/1475

*Originally got 2. Despite identical stickers on the outer retail box, when opened inside one box was black, one box was brown.
*The brown box had stock bios v33, 925/1375.
*The black box had bios v32, 1000/1475.
*The black box one had awful fan noises at max speeds.
*When in crossfire mode, it seemed to me whichever card was on top overheated and had to be shut down. I have an Antec 300 case, with 2 front 120mm intake fans, 120mm side intake, and 120mm exhaust top and rear.
*Planning to return the noisy fan black box version for a refund.
*I did try swapping bios around between the two cards. No problems running on either. Kept the 1000/1475 bios for the brown box.
*Cooling is otherwise fine if the 7970 is on the bottom or by itself with open access to air.
*When I tested stacking the 5870 with 7970, and the 7970 is on top with no open space access, it seemed to cap out at 95C at default clock.

395-400 MH/s, 87C
XFX 5870
OC: 925mhz GPU Core, 300mhz Memory
Default: 850mhz GPU Core, 1200mhz Memory


I'd really like to get a second 7970, preferably with XFX. I'm not sure if the problem is with XFX Quality Control/Cooling Design, or you just need watercooling in 7970 crossfire setups.

slush has been having problems, i think being ddos'd. should check to make sure the pool is up.

also cgminer > guiminer

gettin rdy to bitcoin mine hardcore!

market manipulation!