Bitcoin Forum

If the price of a Bitcoin remains around $14 then is it worth buying a mining rig?

What I am thinking...

I was going to build two mining machines costing in total £2'500 (or around $4'100).
The builds' consist of six 6970s so I would be aiming to achieve a combined hash rate of around 2400 mhash/s .

My electric is charged at 12 pence (around 20 cents) per kilowatt hour.
My six GPUs will use around 200 Watts each. So that's 1.2kWh for them, plus, say another 0.2kWh for the two machines.

So that gives me a total of 1.4kWh. So now it's just a case of multiplying the amount of kilowatt hours by the amount I pay for my electric.

1.4 x 0.12 = 0.168

That means I'll be paying around 17 pence an hour, that's £4.08 a day, £28.56 a week and around £114.24 a month.

So considering my hash rate I should earn around £420 (or $700) a month on average.

That leaves me with an estimated £300 a month profit. It would take 8 months just to pay back my start-up costs.

Is it worth going ahead and buying the components or would you say that with the price of electric where I live it isn't worth it.

I suppose what I am really asking is, are these sort of margins acceptable and if you had access to the money would you go ahead with the above plan?

Please help I can't decide.

I would.

You would be making money in the long run.
And even more if the prices goes up.

In my humble opinion, anything that requires more than 2/3 months to pay the initial investment is not worth it. Difficulty is increasing which will extend those 8 months indefinitely.

Also: the 7000 series should be out soon and your hardware will become outdated.

PS: here's a calculator that estimates difficulty to help you with your choice: http://forum.bitcoin.org/index.php?topic=26751.0

I'd say it's not worth it, try robbing a ATM!

That argument works both ways. But by the very nature of Bitcoin the price should certainly go up.


That's what I was thinking. If it takes over 8 months to pay off then is it worth it. Considering when I do start taking profit it won't be much.
Maybe I should wait for the 7000 series, but to be honest they would have to use 50watts a piece to make them profitable in my part of the world.
If the hash rate increases it would just be cancelled out by a rise in difficulty due to blocks being completed quicker across the network.

So realistically, unless electric comes down in price or Bitcoins increase in value, this isn't a valid investment opportunity really is it?

The thing that burned me was the difficulty increases.  You can't make you calculations based on a static difficulty.  It's going to rise and rise at an somewhat unknown rate (based on hardware availability, bitcoin value and interest level/hype).

That being said, it's an interesting piece of technology and fun to be involved with.  If you're making the decision based purely on monetary gain, it's an investment like anything else.  Sometimes you win, sometimes you lose.

This sums up very well what I think about mining:

http://3.bp.blogspot.com/_A_JUjP28WR4/S4mqkzv0k0I/AAAAAAAAD_M/Yq8SBVv6HNA/s400/El+burro+y+la+zanahoria.jpg

We are the donkey and the carrot is a bitcoin network. We can try to get a faster donkey, but the carrot will always be ahead.

My point is the network always corrects itself. This correction may not be sudden (there are periods of higher profitability than others), but in the long term it evens out. That being said, maybe you can take a few bites at the carrot, but you won't catch it ;)

Well, you got a rig then so if you would use the rig later for something else I think it is a good investement.

No. The only time when it's sensible is if you take less than 2~3 months to recoup. After that, difficulty would likely increase to the point where you will lose money mining unless electricity is free, or BTC shoots up in value.

I arrived at that conclusion while calculating if I should just put together a few 6 GPU sets. This was further reinforced by others who arrived at similar conclusions when taking into account increasing difficulty.

On top of difficulty increases, I also took into account USD devaluation, it's been on the slide for many months relative to my local currency so makes it even less attractive to invest in a full rig.

Adding one or two GPU to an existing system however may be worthwhile.

Did your calculation include fees?

If you meant fees incurred to convert BTC to USD to my local currency, yes. It was part of the forex calculation accounting for likely declining USD value. Basically for my electrical costs, it would take 3 months at constant btc value, difficulty and forex to break even. But since it doesn't, even if only difficulty goes up by an average of 4.5% every week, I'd never break even because electrical costs will definitely go up in the next 24 months.

It's cheaper to buy bitcoins directly at this difficulty/price combination unless you get free electricity.

I don't think dedicated mining rigs are currently profitable.  Using your existing gaming machine to mine in your downtime would be the best bet, really.

Well with the initial startup costs and the electricity rates you have to pay it wouldn't be that wise of a decision imo.

On the other hand, if you can minimize your initial investment and get a nice $/mhash ratio then it's worth considering.  -  I am in the process of assembling an economical mining rig at a cost of approx. $725 with an output of 1125 or more Mhash.... that's a little better ratio than what you are looking at + my electricity is less than 11 cents/kwh.  I won't get rich, and my hourly wage for all of it will be lucky to hit $5/hr but I view it as a hobby as much as anything. :)

That's a good price.  If I may ask, what are you looking at that's going to give that kind of hash output for that little?  I can't seem to find cards that have anywhere near that output:price ratio.

No I didn't take fees into account  :-\

What hardware?

A hobby? But there's not much to do once it's all set up.



I think what I am going to do is wait for the 7000 series cards to come out then reassess the situation.

I think mining rigs are still viable. Unless Bitcoin goes the way of Esperanto...

5x 6770s @ 225 Mhash each - I managed to find a nice deal on a MSI 890FXA-GD70 mobo and a quintet of 6770s for just over $650 all together. The rest of the cost went to a 750 watt PSU and a cheapo CPU.... 1 GB RAM & CPU cooler came out of my spare parts box(es). I realize 215m/hash may be a more realistic outcome, but I am more than happy to tweak the snot out of each and every one of them. :)  Hardware is my hobby, as well as part time job, so I'm happy to mess with these as much as necessary to get the performance I want.

I'd be real fortunate to be a gamer in 1 year when all the super mining computers of today are worth far more as gaming computers, but they are all being sold on the cheap to pay for mining rig upgrades.

IMHO, it's not worth it.

You need to include the difficulty increases in your calculations. Your 8 months could easily stretch into 20 with the current rate of difficulty increases. Most people are making the assumption that BTC will increase in price with difficulty, but so far the price has remained the same.

The only way I see mining being profitable in the long run is having low/no electricity costs and/or BTC value to increase. alot.

A lot of super mining rigs are not set up for cross-fire and by next year, they might not be worth much for gaming purposes compared to just buying a pair of the newest cards.

I think I'm past the point where I want to invest $1,000 or more into a mining rig. However, I've been planning to build a new PC for a while anyway, and mining could help offset the cost of a few components in the short term. The computer I'm on now could use an upgrade from this Radeon 4600 series card too. It scores pretty low on the Windows Experience Index.

So I'm still looking at some cards, but it's probably a good thing I was broke this week. Otherwise I may have spent unwisely.

For anyone looking to get in cheap without trolling endlessly for 5830 and 5850, here's a half decent deal on XFX 5770 for $110 at Tiger Direct. Ends today.

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5316156&CatId=3669 (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5316156&CatId=3669)

I did just possibly find a nice deal on a 5970 though...  ::)

I've done a lot of reading and calculating, and I think it's too late to get in on mining if you're planning on buying a new computer to do it, and running that computer 24/7 when you otherwise wouldn't have done so.

Personally, I already have a computer that has a good ATI graphics card (only one card though :( ) and that computer is already on 24/7 for other reasons.  So I'm using a tiny, tiny bit more power by having the graphics card spun up all the time, but not that much.   For me, bitcoin mining is just a way to make a machine I already had earn a bit of money. 

Is there any way you could cut the cost of that machine you're thinking of building?  If it's just for Bitcoin then you don't need anything fancy, just two bare-bones rigs with the bulk of the cost going to the GPUs?

Agreed. If I were going to build a rig solely for mining, I'd get a cheap motherboard and used cards, put it in a milk crate, etc... The $1,000 rig was using a much nicer mobo, SSD and high end power supply. That way I'm getting the components I wanted for my next build instead of just a mining rig.

My computer is on 24/7 much of the time. If I put another card in this one, I'll probably have to upgrade the power supply though. And if I'm gonna buy a new power supply, I might as well just start building a new rig.