The Steam sale is going on right now and Portal 2 is half-off!  http://store.steampowered.com/app/620/

A copy of Portal 2 costs $25.  But -- there is a 2-pack available for $45, which makes it $22.50 per copy.  Granted, not an amazing savings over just getting one copy, but I can't say not to an opportunity to use Bitcoin and help another Bitcoiner save a little bit of money.  Plus, it could be substantially cheaper for someone who lives in another country.

So here's the deal -- I will either buy or sell a copy of Portal 2 at the median of the ask/bid exchange rate on MtGox * $22.50.  Right now it's trading for 14.4 BTC/USD, so that'd be 1.5625 BTC.  If you would prefer to spend Bitcoins, I'll buy the game on my credit card, you send me 1.5625 BTC, and I'll send you a copy of the game.  If you would prefer to receive Bitcoins, you buy the same through Steam, send the second copy to my Steam account, and I'll send you the Bitcoins.  Whoever has the lower rep sends the goods first.

Note that this sale only runs for the next 23 hours, so if you want it, let me know immediately!

Make a backup before installing a new version just in case it doesn't work.

With this difficulty level and this exchange rate it is a buyer's market.  You're not going to be able to sell used equipment at above new cost.  If you really want it to sell, accept $100 per card.

Um, the screenshot you're showing has the rig outputting less than 1000 MHash/s total.  Yes, every so often it will get lucky and temporarily display a speed of 1100-1200 MHash/s on Deepbit.  By the same token, every so often it will be unlucky, and will display a speed of 700-900 on Deepbit.  You need to take the all-time average, not just the highs.


Well there's your problem.  All of these parts are unnecessary for a dedicated mining rig.  You definitely didn't need that CPU, or that much memory, or a case, or the SSD, and you could've gone with a smaller PSU to boot (around 800-850W).

A few weeks ago I put together a rig, NEW, for $950, composed of 4x5830s, that outputs 1240 MHash/s (that's average, not peak).  So to charge more than that for a used rig that outputs fewer MHash/s, well ... I don't think you're going to find many potential buyers.

Two 6970s should have a higher hashing rate than one 6990.  I wouldn't necessarily return them.

People who are mining Namecoin at the moment are doing it because they believe in Namecoin.  They like the idea and they want it to succeed.  It's no different than people who are putting time and effort into Bitcoin because they like the idea and they want it to succeed.  And Namecoin won't succeed if the hashing power is so low that anyone can trivially take over the network, or if new blocks are being found very infrequently because the difficulty rocketed up when it was more lucrative than Bitcoin mining, but then everyone left when it wasn't.

Can you link to some specific boards in that price range that are known to work with 4x cards using x1 risers?  It seems kind of hit and miss to just pick one at random, because some of them really can't do it.

4x5830, each at 975/335, using latest Phoenix and phatk kernel, getting about 311 MHash/s per card.  I tried pushing up to 985/335, but something crashed overnight and I lost some hours of mining (and had to reboot in the morning).  The system has been running stable at 975/335 for days though, so that seems achievable with my setup.  Temps on the hottest card are around 66-68 degC (yay open case with a box fan).

I'm simply not necessary.  I'm running my cards just about as fast as they can possibly go.  My secret?  No case + box fan.  Which is much, much easier than a submerged setup, I assure you.

The last price the 5830s was available at was $130, not $110.  Using that figure the ratio comes out to 1.445 for the 5830 rig, so the 5870 rig is actually more economical.

Not that I would dream of buying new rigs right now!

You want to install the "locate" package.  Worked for me in Linuxcoin.

X = Anything I am presently forced to use PayPal for.

The birthday problem isn't relevant though.  Say you generated 2^80 addresses and managed to collide two, well, odds are better than 2^50 to 1 that the collision you just found is with another address that you created ... that has no money on it.  So it's not a birthday problem; you need to collide with one of the vanishingly small number of addresses (out of the entire keyspace) that actually has an appreciable amount of money stored in it.

I've spent $1660 on ~2370 MHash/s, or about 70 cents per MHash/s.  Not too shabby, especially in comparison to some of the other numbers on here!  It helps that $310 of the $1660 was to purchase two 5850s that went into otherwise already-bought-and-paid-for computers.  I only have a rig and a half that was purchased specifically for mining.

More info here: http://tinyurl.com/3bnlzbq

At this difficulty level with this exchange rate a 5830 will never pay for itself.  Hence why I'm not buying any, and probably also why not a lot of other people are either, and thus why they're still in stock.

Here's my 4x5830 rig.  Two cards are running directly on the mobo, two are running on PCIe adapter cables in the second tier.  Yes, the skeletal chassis as such is an old table that was taken apart and put back together.  I've since moved this setup from my dining room table to a small desk in the basement and it has a box fan on one side blowing through the videocards (the temps are quite low).  Each card is putting out 310 MHash/s for 1240 MHash/s total.  Oh, and the OS is Linuxcoin running on a USB flash drive.

even with the returns down 40%, it is still very much profitable. Hmm... 300%+ annual ROI via bitcoin mining vs 3% from money sitting in a bank account... Hell, in the 'real' world people jump for joy if they get anything above 10%! Would you call it a good investment if it took you 10 years to pay off your rig? But of course, we are just getting started, as profitable it may look today, it may not be so tomorrow.
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The two situations aren't comparable though.  Money in a bank account just sits there and collects interest.  Money put into a Bitcoin mining rig requires constant fussing with; you need to upgrade software as newer versions come along, keep the rig up and running through power failures, mining pool failures, potential hardware failures, and pay continual electricity bills.

Mining rigs have to pay themselves off in a manner of months.  The exponentially increasing difficulty level means that any rig will output most of its lifetime Bitcoins (>90%) within the first few months.  After that it's just peanuts.  So talking about it on a scale of ten years is meaningless.  Besides, there isn't a mining rig that exists today that will be worth running anything close to ten years from now.  New hardware will come along that is more efficient in terms of electricity used and will make anything we're running today not even profitable to run for mining within a few years.

For a dedicated mining rig, Linux is a no-brainer.  Linux is free (in speech but more applicably here also as in beer), whereas Windows is going to run you $100-200.  There are lots of arguments over which is faster, but I can pretty much guarantee you that even if Windows is somehow faster, it's not $100-200 faster.

I just got Linuxcoin 0.2.1b up and running and it worked very well out of the box.  I must tip my hat to you on a great release.  I only had to make some minor changes (run aticonfig --adapter=all --initial -f again, change permissions/ownership on /opt/miners/phoenix/ , do svn update from within /opt/miners/phoenix/ to get the latest version with the +3% speed boost Ma() function, copy over the /etc/OpenCL directory from another computer because for whatever reason the AMD EULA popup never appeared and thus those files never got written, and then there's the unfortunate issue with /var/run/screen having the wrong permissions set with every boot).

But anyway, all of those tweaks took no more than 30 minutes, which is an excellent price to pay for getting access to Catalyst 11.6!  I have my four 5830s running at 960,335 MHz clock speeds now (up from a limit of 900 on Linuxcoin 0.2a with Catalyst 11.5).  Each one is pushing around 304-305 MHash/s for a total rig output of 1220 MHash/s.  That is way more than I ever thought these 5830s were going to be able to output, and they're all running at below 70degC to boot!

And you did a good job listening to all of the suggestions in here.  I don't see a one that didn't make it in.  Hell, you even included the firmware-atheros package, so 0.2.1b worked out of the box with my wireless card without even having to copy that driver over on a USB stick.  Very nice    I just sent you a donation.  You earned it!