/edit 3 Sep 11. Added photo link and returned from 4 weeks out of the UK, so updating post.

I'm selling my fully operational mining rig as I am regularly out of the country, so can't leave it running anymore.

GPUs: 3 x XFX Radeon HD5870 1GB (Single resistor dummy plug on cards 2 and 3)
Motherboard: Intel 975XBX
CPU: Intel E6400 & HSF
PSU: Coolermaster Gold Silent 700W (80+ Gold certified)
RAM: 1 GB Crucial DDR2
Hard Drive: Western Digital SATA 250 GB
DVD: Pioneer IDE A105 slot DVD (not connected, but cables present).
Case: Tower case with exhaust fan at front and rear and two inlet fans blowing air directly onto the 3 graphics cards from holes cut in the case side panel. This keeps the cards cooler than having air blow onto the cards with the case removed.

The HD 5870s run at 920/300 to reduce the heat and power consumption slightly, although they can go higher. They produce over 400 GH/s each with Phoenix using the latest phatk kernel on Windows XP with the 11.6 ATI drivers and SDK, for a total of just over 1,200 GH/s.

I will leave the OS on the hard drive, which is a valid Windows XP install, and will also leave all the configurations set up with just the username and passwords blanked. There are three separate installations of Phoenix for each card, so 9 in total. The batch files are setup for BTCguild.com, bitcoins.lc and bitcoinpool.com. The aggression timings have been tuned to maximise the total GH/s for the PC.

£535 collection or £550 inc P&P.

I will accept payment by Paypal, but the price will increase by £10 to partially cover their 3% fee.

PM or post replies here.

http://www.wired.com/threatlevel/2011/06/bitcoin-malware/

I am trying to use 2 AMD cards at the same time and I'm having some hiccups, so i'd be grateful for any help.

On my PC, Abit P5Q pro motherboard, I have a 5870 that I want to use for mining all the time and a 4870 that I want to use for the desktop and games. The 5870 device 0 in the top PCIe slot and the 4870 is device 1 in the lower PCIe slot. At the moment, the only way I can make it do what I want is as follows:

Crossfire the 2 cards.
Boot up with monitor attached to 5870
Use MSI Afterburner, set 5870 as master and adjust settings for mining
Run miner
Disconnect monitor from 5870 and reconnect to 4870
Run games

If I boot up connected to the 4870 or swap the monitor over to the 4870, MSI Afterburner won't let me change any settings on the 5870, even if 5870 is set as the master card. If I now change the master card in Afterburner to the 4870, I can adjust this cards settings.

Is there a simpler way I can tell the PC to mine with the 5870 and play games with the 4870? I thought I wouldn't need to Crossfire, but if I don't, the card that isn't connected to the monitor do anything.

/edit Should have said that I'm running Windows 7, 64 bit, and AMD 11.3 Catalyst.

Does anyone have a list of motherboards that will take multiple 2-slot wide PCIe graphic cards. The older the better, as I'd like to use a cheap, low power CPU if possible. I've looked at some, but there doesn't appear to be sufficient space for 2-slot cards.

Thanks.

I've done some sums to see what the profitability is of mining BTC and I'll post my results below.

My overclocked 5870 is working at 344 MH/s. it can go faster, but it gets too hot and the fan makes too much noise, so I dropped the speed down a notch (reducing the clock speed did not make a noticeable impact on the power use).

Using http://www.alloscomp.com/bitcoin/calculator.php, 344 MH/s equates to an average time of 11 days, 21 hours, 35 minutes to mine 50 BTC. This means that my PC will mine 128 BTC a month, on average.

The current value of a BTC is approx $0.70 and the exchange rate is approx $1.60 to £1.00, so I am generating approx £56 per month.

The electric cost is 8 pence per kWh, as the expensive rate for the first x kWh is already being met by normal usage in the house, and the PC uses 300W in BTC mining mode with the monitor turned off. This means that the PC will cost £18 a month to run. In the long term I may try and build a more energy efficient mining rig, as my current PC has 2 sound cards, 3 HDDs and a quad core CPU.

I am making just over £38 a month as profit. This will obviously change as the BTC difficulty and market value fluctuate, but it may be of interest to some people.

It is worth noting that when I was mining with my HD 4870 I was actually losing £1.00 a month....

If I have a given MH/s how do I calculate the % chance of finding a BTC?