Getting Three Cards Mining | Bitcointalksearch.org

carborundum

newbie

Activity: 57

Merit: 0

Quote from: crazyates on March 25, 2013, 12:54:48 PM

For a PSU, you're going to want somewhere around a 700+W PSU. Make sure it's Single Rail. To run 3 GPUs, you're going to need 6x 6pin PCIe power plugs. Even if your PSU only has 4, you can use 2x molex->PCIe power adapters. Many GPUs come with one of these out of the box, but if they don't, they're very cheap and easy to find.

As far as CF is concerned, the general conclusion is that it's pointless to turn on. I would just skip it, and run them as 3 separate GPUs.

I got a cheap £24 PSU rated at 800W but it blows out when I attach an extra 5770 to two 5850's So I guess its a case of get a decent quality PSU as well Cheesy

redmist

full member

Activity: 224

Merit: 100

Quote from: crazyates on March 25, 2013, 12:54:48 PM

I made that recommendation because it's a relatively inexpensive option, but if you're looking for something that has 6x(6+2) power connectors, check this: http://www.newegg.com/Product/Product.aspx?Item=N82E16817171048

Weird thing about a 8 pin PCIe power connector: it's exactly the same as a 6 pin PCIe power connector, except it has 2 more ground lines added. It doesn't add any extra power lines.

I've also never heard about a PSU affecting your fan control, but missing 2 ground lines could cause that. If it's got an 8 pin connector, it's best to fill with an 8 pin plug.

Oh okay. Thanks for the recommendation! Do you think I'd be better off with that one, or trying to find one that has 5x6pin with 1x(6+2)?

crazyates

legendary

Activity: 952

Merit: 1000

Quote from: redmist on March 25, 2013, 04:58:55 PM

Quote from: crazyates on March 25, 2013, 12:54:48 PM

For a PSU, you're going to want somewhere around a 700+W PSU. Make sure it's Single Rail. To run 3 GPUs, you're going to need 6x 6pin PCIe power plugs. Even if your PSU only has 4, you can use 2x molex->PCIe power adapters. Many GPUs come with one of these out of the box, but if they don't, they're very cheap and easy to find.

As far as CF is concerned, the general conclusion is that it's pointless to turn on. I would just skip it, and run them as 3 separate GPUs.

Thanks for the advice crazyates, however I forgot to mention something that is pretty important.
I have the Sapphire 5850 Toxic 2GB version, and it requires 1x6 pin and 1x8 pin power connectors. Its pretty weird. I mean, it works with just two six pins, but the fan speed fluctuates randomly, so I'm guessing the extra 2 pins are something to do with fan control.
Baring this in mind, what PSU would I need now?
6x6pin with an 8pin as well?
Thanks for your help

I made that recommendation because it's a relatively inexpensive option, but if you're looking for something that has 6x(6+2) power connectors, check this: http://www.newegg.com/Product/Product.aspx?Item=N82E16817171048

Weird thing about a 8 pin PCIe power connector: it's exactly the same as a 6 pin PCIe power connector, except it has 2 more ground lines added. It doesn't add any extra power lines.

I've also never heard about a PSU affecting your fan control, but missing 2 ground lines could cause that. If it's got an 8 pin connector, it's best to fill with an 8 pin plug.

redmist

full member

Activity: 224

Merit: 100

Quote from: crazyates on March 25, 2013, 12:54:48 PM

For a PSU, you're going to want somewhere around a 700+W PSU. Make sure it's Single Rail. To run 3 GPUs, you're going to need 6x 6pin PCIe power plugs. Even if your PSU only has 4, you can use 2x molex->PCIe power adapters. Many GPUs come with one of these out of the box, but if they don't, they're very cheap and easy to find.

As far as CF is concerned, the general conclusion is that it's pointless to turn on. I would just skip it, and run them as 3 separate GPUs.

Thanks for the advice crazyates, however I forgot to mention something that is pretty important.
I have the Sapphire 5850 Toxic 2GB version, and it requires 1x6 pin and 1x8 pin power connectors. Its pretty weird. I mean, it works with just two six pins, but the fan speed fluctuates randomly, so I'm guessing the extra 2 pins are something to do with fan control.
Baring this in mind, what PSU would I need now?
6x6pin with an 8pin as well?
Thanks for your help

crazyates

legendary

Activity: 952

Merit: 1000

For a PSU, you're going to want somewhere around a 700+W PSU. Make sure it's Single Rail. To run 3 GPUs, you're going to need 6x 6pin PCIe power plugs. Even if your PSU only has 4, you can use 2x molex->PCIe power adapters. Many GPUs come with one of these out of the box, but if they don't, they're very cheap and easy to find.

As far as CF is concerned, the general conclusion is that it's pointless to turn on. I would just skip it, and run them as 3 separate GPUs.

redmist

full member

Activity: 224

Merit: 100

Hi guys,
At the moment, I have a rig with just 1 Sapphire 5850, and I need a bit of advice from someone who's more experienced than me.
Basically, in the next week or 2, I'm gonna grab 2 more 5850's, but I need some help in figuring out what PSU I should get.
I know roughly how much voltage I need, but what I'm trying to figure out is how many PCI Express power connectors I'll need. The PSU I currently have only has enough power connectors for the card I have at the moment, let alone the next two.

A sapphire 5850 requires 2x75 watt 6 pins (all I have on my PSU)
So two more of the same card, should require an extra 4x75 watt 6 pins?
Is that correct? As I'm a little confused about this whole crossfire thing. Do I need crossfire to get the other cards mining? If thats the case, the Sapphire 5850 page says I need 4 x75 watt PCI Express connectors for crossfire for each card.
Basically, can someone clarify if I need crossfire or not to run all 3, and either way, recommend a decent PSU that has enough power connectors to run all three cards.
Thanks

Topic: Getting Three Cards Mining (Read 1089 times)