Bitcoin Forum

I've just finished my first month of mining and have finally stopped buying computer stuff.

Capital                  $8,000    -    21 graphics cards running on 7 motherboards.
MHash/s                 7,000

So I paid $1.14 for each MHash/s capability.  How does that compare to others?

That's a lot more than I've spent.

I think my initial investment was $50, and I've continually reinvested the generated BTC back into my mining rig. I am currently up to 385 MH/s and only out of pocket my initial $50  :D

I started with nothing.  So the cost you see is for everything, motherboards power supplies, etc.  $50 wouldn't buy you any computational power.

True, very true.

I was lucky enough to have an old Dell in my closet. I dusted it off and it had two open PCIe slots  :) So the $50 I mentioned was only to purchase my first GPU, it was a Radeon 5670 I believe.

However, if I were not so lucky, I would be a completely different situation.

Not to make you feel bad, but you'll almost definitely not ever see that back. $1.14 / Mhash is way too much.

Admittedly I bought in the heyday and got lucky in many ways, but my Price was about $2.41 / MHash, or $0.41 / MHash, buying in about 101000 difficulty, and it took me roughly 45 days to cover costs.

The difficulty is now > 10x higher than that, and you're paying almost triple per mhash. It will be rough for you my friend. Admittedly price is higher now but it also varies quite a bit and is not on the up up up that it once was. Best of luck to you though.

For the systems I currently have online I paid around $2200 for 3200ish Mhash.  That's 11 5830s and various other components.

That's not bad at all.  You counting the PSU?  My PSU cost 150-250 each, which is comparable to the mobo, cpu, ram, hd and case put together.  so you are looking at about $400-500 for the non-GPU parts, times 7 = $2800-3500.  That leaves around $4500-$5200 for the gpus.  21 gpus at about $200-250 each, what kind did you get?  5850, 6950?  Either way your MH estimate is pretty accurate if you OC and run aggressive command line args.  

The math works out for me, he spent what it costs and didn't overspend.  Obviously would have been better to buy 2 months ago when GPU costs would have been 1/2 or 2/3 of what they are now, but I don't think you can get much higher than $1.14 per M/Hash at today's prices.

Did you factor in the cost of shelving/computer storage, surge protectors/electrical wiring, fans, and A/C units?  You are going to need at least 20,000 BTU of cooling for that if you live anywhere south of Maine.  That all should run you another $1000 plus, easy.  Bring your total capital cost to more than $1.14 per MHash.  Then you got to factor in rent, unless you already have a sunk cost mortgage on a house with a usable workshop, garage, or extra bedroom.  Recalculate with all that and you might find closer to $1.50 per MH.

I paid about $1500 for three case-less mining rigs + UPS, 6 x 5770, 1200 MH/sec.  Draws 860 watts from the socket, in a non-airconditioned environment.

I may be mistaken with what your trying to show but dollar per megahash (dollar/megahash) is a bit of an awkward ratio because the lower your number the better you did. If you go with megahash per dollar (megahash/dollar) you got .875 megahash for ever dollar you put in. This ratio makes a higher number a better number which is more comprehend able.

Capital                                   987
MHash/s                               1280
Megahash per dollar               1.30

I built three rigs from scratch.  I bought three used gaming computers.  One computer didn't work so I bought a replacement motherboard for it, then I fixed the motherboard added the power supply, CPU, memory and that gave me my seventh rig.  So I have Three computer in cases and 4 sitting open on the table.

The Power Supplies were the most expensive part.  One was $250 and the cheapest was $190.


Not counting any of that.  Just wondering about the capital.  I own my house. Most of my rigs are in my basement where it used to be nice and cool.  For about $30 I added 40 amps of outlets to the basement.  I haven't needed any cooling, just fans on all the open rigs.  I'm burning an extra 2.9 KWatts for about $340 / month.

So you paid a bit more than me.  $1.25  for each MHash/s capability.

I made a rig for ~$600 (with a good case that was probably unnecessary and some already owned hardware) and it puts out ~580 MH/s. So that was 1.03$/MH, or .966MH/$

I also have a 5850 pushing 340MH/s on my gaming computer, but the 5850 was bought before I knew of BTC, so I consider that $0 investment. So that's givng me 0$/MH or InfinityMH/$

Edit: 9.66 MH/s is quite different from .966MH/$

Capital                  $1360
MHash/s                 1748

$0.778 for each Mhash/s
1.285 Mhash/s for each dollar

$2100
2500Mhash/s

I decided to only buy with what I earned.

£25
800mhash

Already had a 5770 and a xfire mobo for my gaming needs so don't class that as outlay as it was before bitcoin

I'm amazed by how inefficient a lot of these builds are that seem to be the norm. I'm curious, how many of you guys at the 1Mhash/$ or below level are near having your setups repaying themselves?

205 eur for 410Mhash/s. card has mined 10btc for me so far.


quite far away from that, even though it's 1.4Mhash/$. problem is, each mined bitcoin costs about 3.20 eur for me (0.22 eur / kWh), so it will take quite a while to have the card pay for itself, if it's even gonna happen at all.

So far about £600 / $960 on 05/07/11

1050 MHash/s


Have a clone of this on order so I can do some side by side research with a friend.
All quality parts with good warrantys to so dont expect hardware failures to be an issue.

May well Dive in after that and get 8 more taking it to 10GHash/s and should cost me under £6000.

You lot in the US got it easy  ;D stuff over here costs an arm and a leg.  >:(

Plan is one hard drive to boot and rule them all. Lol see what i did  ;) ok fail sorry.

Whole things caseless so will be buying an wheeled airport server case and a rather large fan. (not factored in these cost's yet)

Then I can stay at hotels for free  ;D well as long as I don’t trip the MCB that supplies my floor.
Do uk hotels have fair energy use policy’s? I have some more research to do it seems.

Almost definitely? Never? Really?

So what's your best estimate on the probability that he will make back all that he invested (including accumulating electricity costs and possible hardware failures), in a scenario where he sells all of his bitcoins as they come along? "Almost definitely not ever" is so vague, but to me it sounds like 1% at most, possibly 0.1% or even lower. Is that about right?

Brake even isn't when you get your money back for your investment in my mind anyway.
Its when you have sold bitcoins and covered utillitys to the point that you can realisticly ebay off all your hardware and come out even.
The rigs are an asset dont forget.

I don't get how some of you can build such inefficient rigs, especially those of you in the US with your hardware prices :/ My absolutely worst rig is in the 0.9$/MH and I have to deal with the hardware prices in sweden/europe (25% VAT). When the 5850 Xtreme was launched here for example they were in the 175-200$ area and I've yet to see the 5830 Xtreme below 140$. People just seem to be spending way to much on the rest of the hardware rather than on cards where it matters.

$130 for single 5770. I should get some more since i don't seek mh/j efficiency.

Woot messing about in trixx I just made it to about $0.92  ;D
Well happy with this its my first one \o/

Once those PCI risers make it over from Hong Kong I should beable to address some heat issuse's and pust it down even more.

3200$ vs 4020 mhash, 12 5850s, 3 systems with risers

5770 is a horrible $/MH card since each pci-e slot comes with a cost as well, unless you are just filling up slots in your current systems then I would agree it's a decent deal. Also 5770 is actually a pretty decent MH/W card once you downclock the memory.

When I built my rigs the 5770 was the best card available - as 5830s were gone.

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.

im at 12 5850 with riser cards on 3 MBs. Spent 3250 $ for about 4,5 GHash/s. These configs need 2,1 KW and my kitchen became pretty warm :D

Not a bad choice considering the 5830s weren't available.

Yep, filling up slots on existing systems that run 24/7. And i plan putting 2x5830 or 5830 + 5770. And im not after MH/W :)

I'm roughly around $3000 for 3600mhps = $0.83/mhps or 1.2mhps/$

first rig was 4x 5830's at 109 + free ship (wish i had to balls at the time to go all out and just get 12)
Then after cashing out my first coin I ordered 2 more rigs of 4x 6870's.

MSI 890FX GD70's
900watt & 1000watt PSU's

I already had 1 desktop, so that kept my costs down.

Capital: ~$1100

M hashes: ~2000

One rig already had 1x 5830, just added a 2nd 5830 card @ $90.  Does about 580M hashes.

My 2nd rig I built from scratch.  It has 2x 5850's and 1x 5830 running off PCI-E 1x.  That rig cost me $600.  Does about 900M hashes

My 3rd rig my friend and I went 50/50 on.  It has 4x 5830's.  Cost us about $800, but we split the cost and hash rate.  So thats +$400 for about 550M hashes

In 2 months I paid for all hardware investment and put $600 in my pocket.

Between me and my friends, we had 2 unused motherboards with 3 pcie slots total. All we needed were better power supplies and gpus. We put one of them in my friend's desktop as an upgrade to his older graphics card so it's not running as fast as the other 3, but it brings our total up to 4 5830's.

$650 invested
1000 Mhash

1.54 MH/$ or $0.65/MH

^^proud of that.

3x sapphire 5830, $129 each = 387
3x pcie risers, $18
Any board with 3 PCIe slots of any sort, cheapest CPU - $60
Antec 750 watt gamer series, $55 (+2) = 57 AR
1 Gb USB memory stick, $1

Total: $533, should pull nearly 900 Mhash and pull about 600 watts out of the wall.  All of this may still be possible today, was definitely possible last week on newegg.  Even without rebates there are plenty of 700-800 watt PSUs capable of feeding 3 overclocked 5830s under $100, so call it $600 for 900 Mhash or 1.5 Mhash/$ or .66 $/Mhash.

Assuming fixed difficulty this gets nearly half a bitcoin a day.  Let's call it $6 after power costs, or 180 a month.  3 and change month ROI.

OP's builds require more than 6 months of no difficulty increases and $15/BTC exchange rates.  Good luck with that.  I'd send that crap back and eat the restocking fee if I was him.

I only got into mining because I got bulk 5830's, 5850's and 6990's cheap (-30-40% under market price).

For example, 8x 5830's for $792 (2400mhash/s). 5x 6990 for $2600, (4000mhash/s). Bunch of sapphire 5850's xtremes at $99 each.  There's of course PSU and mobo costs too, but IMO if you can get great deals, mining is still worth it.

Don't just go to Newegg and buy the most expensive thing. Look around, make phone calls and see if importers have some cheap ones.

Here's another way to look at the OP's investment.  He could have spent $8000 on bitcoins.  I'm sure they'll be $13 again this weekend, so I'll use that as the price.

8000/13 = 615

At 7 gigahash the OP should be mining around 3.5 bitcoins a day, at a power cost of at least .5 btc/day.  Now assuming no difficulty increases we're talking 200 days to earn that many BTC.

Look at prices and difficulties right around the end of last year (200 days ago) to guestimate how likely it is your hardware will *ever* generate anywhere near 600 bitcoins over its lifetime.  You've just bet 8000 dollars no ASIC of FPGA miners get introduced until well into next year, and the 7 series radeons won't be very good at mining -- both very poor bets.

the op made a sloppy investment. You should be able to get at least 1.3 megahash per dollar easily. He gets .875
$8000*1.3=10.4 gigahash

Under current difficulty that's 6.693 BTC I assume that .5 btc is still acceptable because some of the slower more expensive cards consume more power.

So 615/6.193 a day =99 days

So in about 3 months he will have the same amount after that he will continue to gain more bitcoins then the original possible investment.

edit: If for example he went with the most extreme case he could get 1.58 megahash per total cost with 5830's at 110.
$8000*1.58=12.64 gigahash
thats 8.134-.5=7.634

615/7.634= 80 days

Oh, I agree an efficient builder can still make the case for mining.  The OP is far from an efficient builder.  In fact, it'd be hard to build less efficiently unless you buy 6850s at ebay markups to go with $250 blinged out PSUs, $200 gamer cases and $400 gamer motherboards in addition to getting hard drives and windows licenses.  The OP is a classic case for buying efficiently mined BTCs instead of overpriced mining gear as a BTC investment.

Also, your 3 month timeframe for an efficient builder (see: my post above) ignores the possibility of hardware failure, brownouts, downtime due to DoSed pools, network outage, and a wildly spiking difficulty.

True I'm sure as you gain more hardware there will be more failures but there isn't really a way to calculate that. Also I doubt all pools will be ddosed at the same time and worse case at that power he could still mine independently. Also the difficulty shouldn't be unpredictable as long as the price doesn't go sky high.

Not to mention that he could sell those 615 bitcoins for 16 dollars within 1-3 days of buying them at 13 making him $1840 within a week.  He could probably do this multiple times.  If he bought again using all $9840 at 13 he would have 757 coins and could cash out at $12112 if it hit 16 again.  Thus making more than he could ever hope to mine in the matter of 1-2 weeks.

Day trading can be very risky and I honestly wouldn't recommend it with 8000 dollars on the line.

I'd also like to point out that with hardware he has a way to recoup some if not close to all of his money back. If he buys coins then he doesn't get that security blanket.

More risk, but much more reward.

Considering how risky bitcoin is already why would you want to add to that?

That's the point. With a higher risk on initial investment, you have a greater potential reward. Say you buy $8k worth of BTC for $14 and sell for $17. You get much more out of that than buying $100 of BTC.

I also understand where you're coming from: the safer standpoint, which is where I stand too, so don't take this as me bashing you  ;)

I also understand where he is comming from, but when it is about money... No guts, no glory :)