Bitcoin mining with 2 graphics cards & a Corsair 400CX?

New to PC silencing? Read & post your questions here. Dedicated to rosy_toes.

Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee

Post Reply
btcminer
Posts: 5
Joined: Wed Jul 27, 2011 1:18 am

Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by btcminer » Wed Jul 27, 2011 1:55 am

About 2 yrs ago I arranged for my new PC to be supplied with a Corsair 400CX PSU (http://www.silentpcreview.com/Corsair_CX400W) thanks to the reviews available here (which was by far the best resource on PSU's I could find).

I've happened to get into the fad(?) of bitcoin mining, which involves running ATI graphics cards at near 100% of their capability constantly. Currently, I have an ATI 5770 graphics card. The graphics card and the CPU running at 100% draw around 95 watts of power according the power meter I have, but around 71 watts most of the time while the CPU isn't too busy.

I'm considering purchasing an additional ATI 5850 graphics card, and running both cards in the same box. (Side note: I only have one PCIe x16 slot, but will use a PCIe x4 to x16 extender cable for the 5770 card). The 5850 card apparently requires two 6pin PCIe power cables apparently, as it can draw maybe up to 160W. Currently, the only 6 pin PCIe cable is in use by the 5770 card. 4-pin molex cables can be paired into a single 6 pin PCIe cable, but it's recommended to use separate molex cables to reduce the load through each cable. That would mean I need 4 separate molex cables, but I only have 3 - is it going to matter if the 5770 draws it's power through a single molex? (Fire risk? Risk of hardware failure?)

Secondly, system requirements from the retailer I use state "500 Watt Power Supply is required" for the Sapphire ATI 5850, though the benchmark tests appear to show a max draw (through a power meter) of an additional 160W. As the PSU I have can actually meet it's rated wattage, a total power draw of between 230 and 255 watts shouldn't push it too hard, should it?

Thanks!

dhanson865
Posts: 2198
Joined: Thu Feb 10, 2005 11:20 am
Location: TN, USA

Re: Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by dhanson865 » Wed Jul 27, 2011 11:25 am

btcminer wrote:About 2 yrs ago I arranged for my new PC to be supplied with a Corsair 400CX PSU (http://www.silentpcreview.com/Corsair_CX400W) thanks to the reviews available here (which was by far the best resource on PSU's I could find).

I've happened to get into the fad(?) of bitcoin mining, which involves running ATI graphics cards at near 100% of their capability constantly. Currently, I have an ATI 5770 graphics card. The graphics card and the CPU running at 100% draw around 95 watts of power according the power meter I have, but around 71 watts most of the time while the CPU isn't too busy.

I'm considering purchasing an additional ATI 5850 graphics card, and running both cards in the same box. (Side note: I only have one PCIe x16 slot, but will use a PCIe x4 to x16 extender cable for the 5770 card). The 5850 card apparently requires two 6pin PCIe power cables apparently, as it can draw maybe up to 160W. Currently, the only 6 pin PCIe cable is in use by the 5770 card. 4-pin molex cables can be paired into a single 6 pin PCIe cable, but it's recommended to use separate molex cables to reduce the load through each cable. That would mean I need 4 separate molex cables, but I only have 3 - is it going to matter if the 5770 draws it's power through a single molex? (Fire risk? Risk of hardware failure?)

Secondly, system requirements from the retailer I use state "500 Watt Power Supply is required" for the Sapphire ATI 5850, though the benchmark tests appear to show a max draw (through a power meter) of an additional 160W. As the PSU I have can actually meet it's rated wattage, a total power draw of between 230 and 255 watts shouldn't push it too hard, should it?

Thanks!
At 200+ watts continuous load that PSU will run the fan at or near 100%. If you care about noise that will be too loud.

If you want to be cheap about it use only the 5850 until you are sure it works OK then sell the 5770 to someone else.

Though I'd be looking at other cards if you are serious about bitmining. http://bitminer.info/ says that you'd be better off getting a 6790 assuming you aren't getting the 5850 for some extreme discount.

ces
Posts: 3395
Joined: Thu Feb 04, 2010 6:06 pm
Location: US

Re: Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by ces » Wed Jul 27, 2011 11:48 am

I have heard about bitcoins. But what is bit coin mining?

btcminer
Posts: 5
Joined: Wed Jul 27, 2011 1:18 am

Re: Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by btcminer » Wed Jul 27, 2011 2:45 pm

"mining" is essentially the metaphorical name given to the back-end transaction processing for the Bitcoin network, mainly because the process involves random payouts at infrequent intervals, kind of like looking for gold nuggets. I got so frustrated with seeing articles that didn't get to the essence of why Bitcoins are useful that I wrote an article on the topic myself, in case you're interested: http://www.experts-exchange.com/Softwar ... teers.html

Thanks, dhanson for your comments - I suspect you're right that it's a bad idea to try to run both cards at once, and your advice is sensible. I'm keen on the 5850 because it maximises the output for my budget (a more detailed comparison is available here: https://en.bitcoin.it/wiki/Mining_hardware_comparison ), but also because it's available from the local supplier I trust the most (the 6790 is not).

Zargon
Posts: 77
Joined: Sat Feb 20, 2010 9:00 am
Location: Urbana, IL

Re: Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by Zargon » Mon Aug 08, 2011 10:23 am

the 6970 would take ages to break even.

merlin
Friend of SPCR
Posts: 717
Joined: Mon Jun 13, 2005 6:48 am
Location: San Francisco, CA

Re: Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by merlin » Mon Aug 08, 2011 3:38 pm

Bitcoins looks like it's dying now. The value has plummeted recently and it gets harder and harder to get more coins over time.

btcminer
Posts: 5
Joined: Wed Jul 27, 2011 1:18 am

Re: Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by btcminer » Mon Aug 08, 2011 5:16 pm

The exchange rate is still highly volatile, and the recent drop was probably caused by the disappearance (since explained) of the mybitcoin.com website along with a substantial number of coins stored within it. It's hardly surprising, since the website wasn't exactly professionally run. After several days of no response, the site owner has claimed the site was hacked and a proportion of the coins stolen. Such incidents will probably continue until organisations can show they are trustworthy.

The integrity of the bitcoin technology itself is still sound though.

Zargon
Posts: 77
Joined: Sat Feb 20, 2010 9:00 am
Location: Urbana, IL

Re: Bitcoin mining with 2 graphics cards & a Corsair 400CX?

Post by Zargon » Tue Aug 09, 2011 4:47 am

btcminer wrote:
The integrity of the bitcoin technology itself is still sound though.

well, more or less atleast :p

Post Reply