Bitcoin Forum

Hello, all.  I'd like to get the opinion of this forum.

If I were to spend $700 on a mining rig and get 600 MH/s out of it, and get it online in a week from today, would it pay for itself eventually?

The mining calculators say no, because they assume the difficulty will forever go up.  But the difficulty has to stop and level off at some point, right?  At some point, new miners will stop coming in, or current miners leaving, or shutting down part of their rigs will match new miners coming in.  Right?

I suppose the $ value of BTC could shoot up, and that would definitely help.  It could also go down.

Is it just stupid to buy a $700 new rig now?  I just want to break even, without factoring in selling the used hardware later.

BTW, I currently run 1 5830 at 300 MH/s.  But that was easy, I just stuck a new 5830 in my existing computer.  I'm proposing buying a whole new rig.  And the $700 comes from what I specced out at NewEgg.  Closed case system.  I can't have TOO much fan noise and hardware just sitting out.

Thanks for your opinion.

600 Mhps? Really?
Think again: https://en.bitcoin.it/wiki/Mining_rig

You're asking if difficulty will eventually level off because "new miners will stop coming in" and you're asking if you should start mining?
Yea, that's why the difficulty is going to keep going.

I would not spend $700 on a new rig right now, unless that $700 is going to net you a minimum of 1GHash.  You should be able to get a 600Mhash rig for under $400 right now, so 1.2Ghash for $800.

No one knows the future. The current forecast for paying off a rig at $1/MHash is about 6 months. This expects both difficulty and price to remain constant though. Either could change at any time.

I would suggest building more efficiently though if you worry about a rig paying itself off, < $1/MHash is bad efficiency, and makes it less likely to pay itself off.

Thanks for that link, it looks like I can go cheaper than $700

I'm curious how you would build a rig for under 400 dollars and get 600 megahash. Considering the 5830 is at 130. I did a quick calc and I'm just a little higher then $400 for 600 megahash and that's before shipping.

Using the link provided by jackjack, I specced out a 600 MH/s system on NewEgg / Amazon, with a case, for $592, shipped.

That's under the magic $1 per MH/s

I'm glad it helped
You can now spend $100 to help Bitcoin economy ;)

If gambling sites that take BTC count as the "Bitcoin economy", I'm half way there since Monday.   :-\

http://forum.bitcoin.org/index.php?topic=30536.0

You think I should try to hunt down some 6990's ? I don't have that kind of cash.

I'm in the "you can't know for sure" camp on this question, mainly due to uncertainty in BTC price. One thing that makes it tough to build right now is that the GPU market is really lean. There don't seem to be many exciting cost effective options out there atm. Nothing like 5830s for $109 or 5850s for $150, or 5870s for $190.
 >:( 

That's why if you want to buy a machine you wait till you find some deal like that :P Don't be impulsive and buy the first item you can.

Depends on your power costs.  That PC would recover its costs within 6 to 12 months.  You've also got to count on bitcoin's price dropping below $10 in your calculations.  Depending on your climate the extra heat generated may be welcome in winter, but cause even more power consumption in summer.  It's the hidden cost of cooling that most miners never take into account.

Many people once hoped that bitcoin's value would continue to go up with difficulty, yet for the past several difficulty increases this has proved to be the exact opposite.  Price goes down with increased difficulty.  As difficulty goes up the hype of getting rich by running your GPU flat out disappears, and with it the interest of new people to keep the whole thing going.

I honestly don't think that's true. Non miners could care less where the difficulty is. The reason the price dropped from 30 to its current is because of a lack of faith in its value. This is due to several hacking incidents not to a rising difficulty.

I'm in San Diego, by the beach, so no air conditioning, we just have a window fan.  The Pacific Ocean is the world biggest air conditioner and it's about 200 yards away.  :)

So - high California power cost, but no additional cooling costs.

2 x 5830s: $260
1 AMD Sempron: $40
2 GB RAM: $20
MSI 870-G45 AM3: $75
Coolmax 750W PSU:  $68
Total:  $463, Total MHash:  626 (could probably squeeze more)

So, just over $400 as you said, but also over 600 MHash.  Could probably go with a slightly cheaper MoBo.

I basically just bought that, plus a case and 2 case fans for $592 shipped from NewEgg.  $540 before tax and shipping.

I, for one, would be ecstatic if my 2x5830 rig returned anywhere near $500 over the next 4 months.   I started mining at $8/btc and under 500k difficulty.  I lucked out and received a bit over $300 since that time.  Most of that in the first 7 days.  I recycled some old hardware so I consider my cost to be $207 for 5830s shipped and $55 for a 750 watt PSU, leaving the rest to pay for $.046/kwhr power.

All I can say is "good luck" and here's hoping!

I wouldn't recommend that much cheaper of a board.  It's pretty minimal and it's going to be taking a lot more heat punishment than normal.  If you don't want to fry your board in a year, ECS and Foxconn and all those crappy ones are out.  I'd go with an ASUS with solid capacitors across the whole board or an MSI military class II board with solid caps across the entire board.  Those can take some serious heat because they have ceramic outsides and non-liquid insides.  Basically any board you get that's worse than that one would be saving $5-10 and totally not be worth the significantly reduced lifetime.

By the way, you forgot some sort of case or case-like object, the hard drive, and at least temporary optical drive to install the OS in that build...and the OS lol.  Linux is a pain to set up and I've done it twice but who doesn't have windows XP licenses laying around?  I've got like 40 activations worth cuz I recycle and refurb and repair computers :D And they haven't cared about the "non-transferrable" part of XP licenses since 2007 when they stopped selling them.

* I'm getting a case.  I have a small house and a wife, so fan noise must be minimized.  However, there are several How-Tos on this board about running caseless. I recommend MeatBall's: http://forum.bitcoin.org/index.php?topic=27496.0
* I plan to run off a USB drive: http://forum.bitcoin.org/index.php?topic=29021.0
* Writing software to run on Linux is my job since 1998, so I'm pretty comfortable with it. :)  I think it's WAY easier to set up than Windows, but to each his own.
* I ordered a MSI 870-G45 for $70.  Good to hear the "Military Class" components are decent.

Thanks!  Constructive criticisim is always welcome.

hahahahahahh oh man. You are killing me!

LinuxCoin takes 10-15 minutes to install in persistent mode from the livecd. Admin time is far far less than Windows as well. I think you may forget that a lot of miners are also sysadmins. If you took a couple of hours to learn how to use it you might be surprised that it's more flexible, stable, cheaper, and easier to use than wasting your time click click clicking around with the mouse.

You can find your mainboard, CPU and RAM in second hand market, some are dirt cheap.

My rig:

Random Mainboard (PCI 1x x 2, PCI 16x x 1) + CPU (fan included) + 512 MB RAM from secondhand market: CN¥210 (US$32.55)
PCI-E 1x to 16x extender cable x 2: CN¥30 (US$4.65)
Sapphire Radeon HD5850 Xtreme x 3: CN¥2940 (US$455.55)
4GB USB Stick: CN¥45 (US$6.95)
Xilence 700W Power Supply Unit (http://item.taobao.com/item.htm?id=10684926101): CN¥195 (US$30.20)
Two more random 300W power supply units from secondhand market to power the 2nd and 3rd HD5850's 6pins: CN¥50 (US$7.75)

Hashrate: 362 Mhash/s * 3 with phoenix and the latest patched phatk kernel, overclocked to 900 MHz core freq = 1.086 Ghash/s
Total cost: CN¥3470, or US$538, or US$495/Ghash

"Military class" components are actually total garbage. The 870-G45 mosfets are some of the lowest quality inferior junk items around. The only goodnews is that if you are running a low power sempron processor, that this won't really be a problem as far as I know. But those boards are notoriously junky boards. The caps might be better, but I suspect that they aren't and that's all just marketing hype nonsense.

You technically could just lay it on some cardboard or the boxes it came in so thats free. You don't need an optical drive you can just boot with a flash drive and I guess you could include 10 15 dollars to his price for the flash drive. Other then that though everything he showed was fine.

The military just uses Sun Netra, Sunfire, and various HP and DELL servers. They certainly aren't buying any MSI motherboards. The 'milspec' marketing term has been around forever and it rarely means the military uses it or even that the product is up to 'military specification'.

Why buy a case?  I run practically that same exact rig, sitting on it's motherboard box, without any external fans, and the cards run right at 69C at 70%.  Putting it in a case is silly and just jacks up the costs because you'll need a more rigorous motherboard (like you pointed out) due to heat, and buying a case and additional fans.  Open air is the way to go for a mining rig.

As for the OS.  You already have a computer, right?  Linuxcoin is free and will boot it from a $5 USB stick.  Again, optical drives and Windows are a waste of money and resources for a mining rig.  Takes 15 minutes to setup the USB stick, boot it, install Smartcoin, and you're done.

Open rig works great until you run out of table space and actually need to organize more than a couple open air rigs. Density efficiency is important for large operations. Just ask Dimitri.

How do you use PCI-E extender cables with an open air rig? That's why I use cases.
Usually the PCI-E x1 slot(s) are in the middle, and most extender cables aren't very long...

Ive seen pictures of ghetto rigs with 5 dollar towel/dish rack that they place the gpu's on. I'm not sure I would do this though.

Never played Tetris?

Like this:
http://forum.bitcoin.org/index.php?topic=29729.0

I'd also argue that this is WAY more dense of a system than a bunch of cases with extra fans loaded into them.  That's 5 two-slot cards on one motherboard.  Four of those in a line would be 20 cards, by making some slight modifications you could easily stack another row on top for 40 cards.

I'm assuming you've actually made this? I'm planning on trying this what temp do the cards get to and what temp is the room?

I haven't done this yet.  However, I run an open air rig and my cards are right at 70C running with 70% fans (I think).  The room ambient temp is around 25C (because of the rigs).

To each his own, I guess.

Some people like to have 2 cards per PC; others like 5. 

It's really a matter of opinion.  It's less hassle to set up 2/3 card machines, but you need more machines.
As far as cost goes, I think it's about the same. If you go to 4/5 card machines, you need to make special arrangements (greater time cost) plus you need a 1200W PSU instead of a 650 or 750. And most mobos only have 2 PCI-E with 1 or 2 PCI-E 1x.

The mobo in the link Rob posted was certainly not $60.

On the other hand, sometimes it's easier to run 2 big rigs instead of 5 smaller ones.
Unless a component fails, then all your eggs are in one (broken) basket.

If you plan to go big (more then 5 gpu's) it is very waisteful to make rigs of 3 gpu's or less because of the space taken and the cost of the extra components. To keep it simple lets do 15 gpu's.

So you would need 5 rigs of 3 gpu's or 3 rigs of 5 gpu's.

Ill set up the cost for a rig with 5 gpu's.

68 - open case as rob has link to.
145 - mobo (http://www.newegg.com/Product/Product.aspx?Item=N82E16813130274R)  -- This is an amazing deal at the moment I highly recommend as it is usually 195.
130x5 - 5830's
30 - cpu (http://www.newegg.com/Product/Product.aspx?Item=N82E16813130274R)
10 - ram (http://www.newegg.com/Product/Product.aspx?Item=N82E16820148368)
219-psu(after rebate http://www.newegg.com/Product/Product.aspx?Item=N82E16817171055)
9 - flash drive(http://www.newegg.com/Product/Product.aspx?Item=N82E16820171398)
15*5 risers
totaling to $1,206

Now 3 gpu rig in a case.
130x3-5830's
30-cpu
10-ram
9- flash drive
127 - mobo(http://www.newegg.com/Product/Product.aspx?Item=N82E16813157207)
50 - case(http://www.newegg.com/Product/Product.aspx?Item=N82E16811119068)
110 - psu (http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006)
totaling to $726

726*5   =$4356
1,206*3=$3618

That means the 3 gpu rig costs 20% more.

You can get 2x (58xx or 6xxx using a total of 300 watt PCIe power connector) and 2x5770 (150 watts of PCIe) cards into one case. I know this because I'm doing it. That keeps the cost down significantly because you can run a 600-700 watt PSU depending on CPU. And when you get over the 3 box hump you can't realistically (unless you feel like spreading parts around on a large table or baking rack and filling the room with oscillating fans) put them in one location without looking like a degenerate that doesn't care about consistency and stability.  ::)

4 cards per box is the best use of space when you're dealing with 3+ boxes. There's also the power distribution, networking cables, environment cooling and heat exhaust systems, and administrative work to consider. Having all of your gear in an orderly arrangement keeps you sane. I know a lot of people here love open cases but coming from a datacenter work environment it just makes me think you're playing with toys when you could be approaching it in a serious manner.

First 4 5830's always will beat a set up like this in megahash/(server cost) unless you get insane deals which I have never seen. Secondly I chose 3 because that was the amount argued.


If you read I said using the open case set up that rob linked to. This is still a case with a frame just completely open and spreads the cards out significantly. Here is the link since you didn't bother looking up a couple posts.
http://forum.bitcoin.org/index.php?topic=29729.0


Again see the case I linked to above.

Yes, there's resale value.

If you had to resell any of it, as in the oft-quoted, "...and I'll have several PCs and graphics cards that I could always re-sell..."
it would certainly be easier if it had a case.

Barebones components such as Motherboard/Sempron combos are much harder to sell. For one thing, they only appeal to a small segment of the population --techies -- who tend to know about things like NewEgg and how they're wiser to spend $20 or $30 more for 3X the processing power :)

I often wonder how well all these "mining rigs" people put together (myself included) are going to sell on Craigslist someday.

Also, a case provides more protection against things like beverages, pets, children, and earthquakes.

I agree resale for a case I just listed would be an absolute bitch but if you think you have to rely on the resale to make a profit then you shouldn't be investing in bitcoins. I also agree an open case like the one listed could be damaged easily but as long as you realize that then you should be able to use common sense and keep it in a safe location.

The DIY aluminum case (in the post you linked to) is pretty slick -- the main problem I have with it is: time. I don't have that level of free time for mechanical tinkering.
That thing costs *quite a bit* if you factor in even $8/hour for your time.

True, there's the "learning experience" factor, which we've all indulged in for building rigs. But you only have so much time to learn ;)

I agree. I don't have the time to sit around cutting and drilling and measuring. A $50-60 4U rackmount case and a couple of 120mm fans is faster to deploy, easier to resell, easier to manage, and all around more professional.

Imaging trying to resell that - "I made this case in my garage! It's really awesome I swear."

As long as you have the equipment I'd assume it could take no more then an hour to build I have some previous experience with the tools not much though.

if you ask me.. you need to find someone getting out of bitcoin mining and just buy their rigs.
for example, a while ago i bought two boxes... 5830x2 in each.. for 400 each. The usual setup
we all tend to buy on newegg with cheap cases. I just leave the side off.

so that was 1200+ mh/s for 800 dollars..

my other box has more serious parts in it because i plan to keep it long term to replace my
antique i am typing on now which has a nvidia 8800GT in it. So that box consists of
2x reference 6950s with shaders unlocked, the really nice MSI MB mentioned above, a nice
1000 watt power supply, etc.. Naturally the other parts are dirt cheap just to get it running
like a sempron and cheap ram. Once I am done with mining I will rebuy those parts to make it
more of a serious workstation/gaming machine (plus those parts will be cheaper down the road).
I also stuck a used 5850 in it to fill it out more. No case yet.

So now I am at ~2000 for 2400+ mh/s...

plus the rebates are finally starting to trickle in! just got another 25 dollar check today.
it is the MSI rebates i worry about. darn pricks are slow.

So it all depends on your goal. If you plan to replace an old computer make sure the core
parts are high quality. Don't feel bad about spending more on those. The rest buy cheap
to get it going. But once that is done.. man o man.. you need to find some great deals
to drop down the mh per dollar equation.

P.S. the price also includes a legit windows 7 x64 professional license that i plan to use
for many years to come. the other two boxes are not so legit if you follow me ;-)

as of right now i am pretty happy with what i have.. and really am not desiring to buy
more unless a great deal comes along. And the longer you wait.. with diff going up...
it just gets worse and worse.

As long as you bring in more than you pay in electric then it's all good.

Not really fair when you pick different quality PSU for the rigs, especially a, IMO, lower quality & cheaper one for the 5 card setup. An equivalent Corsair 1200AX would cost another US$40 more, closing the gap by US$120.

Also you're getting a required high end board only at $145 because of a special offer, which may not be valid tomorrow for all we know, so let's throw that in $50x3 difference.

Since we're using risers here, no reasons why we cannot make use of 1x PCIe slots as well. Boards which have 3x PCIe slots of any variety are commonly available on Newegg for $100 or less. So that reduces the 5x rigs by $27 each or $135 difference.

Now add in the time spent to purchase and assemble the open rig frame, say 2 hours average each at a labour cost of US$10/hr for $60 total.

During that 6 hours, the 3-gpu rigs would had been mining away at some 4500~5000MH/s which could possibly net up to 1BTC, not a lot but if there was a lucky streak during that 6 hours, it could be more.

Adjusted amounts would be US$4221 vs US$3948, ignoring possible gains from mining first, which is less than 7% difference ;)

The 1200w psu I picked out isn't bad I mean I picked out an 80 plus gold and cooler masters isn't a bad company. The corsair for the 750w I chose is only 80 plus(not gold) so they may be different brands but they are both fine.

I agree you could go cheaper with the the 5 gpu mobo I just chose that because it is the mobo I use.

I honestly consider bitcoins a hobby and I wouldn't consider the 2 hours building the rig wasted. Also if you learned how to build the rig once it would drastically take down the build time for the next two. You could easily shave 2 hours off that time. Another thing to consider is you could build all 3 rigs at the same time and it would cut down on transition time between steps. I bet if you did all three at the same time it would take no longer then 3 hours.

I'd also like to point out build time for putting the pieces in the case and relocating the wires so it stays cool takes time too for the 3 gpu cases. There's 5 of them to put together as apposed to three so I bet it would take even the most skilled computer builder at least 2 hours to put together 5 computers.

This makes the gap even larger again (too lazy to recalc the numbers) but I bet it would be closer to 15%

I was estimating maybe 3hrs for the first attempt with the usual first time mistakes, then 2 and finally 1 so averaging 2/rig. But this really depends on the person's skills so we could both be right and wrong :D


Quite true, I overlooked this part also. Although around here, I usually order new systems assembled and it only costs about $10 extra.


Agreed it's probably closer to 10~15% rather than our highest/lowest estimates. :)

We're just nitpicking :P I think we can both agree a 5 rig set up is better then a 3

I have a "casual" rig, and I'm using bitcoins to (slowly) build up a gaming rig.
 
You see, (and I pointed this out in a different thread) my casual rig is starting from a net value of "zero" as in "not in debt", because I look at it like this:  My wife let me purchase X dollars worth of gaming machine last year, and won't let me purchase anything new for a few more years.  So bitcoins aren't "real money" to her, and thusly anything I mine is positive gain.
 
I bought a second 5770 with bitcoins.  I just purchased a Corsair 800D case (I need it for cooling future cards since my other case sucks) and will continue to slowly piecemeal together a nice gaming rig.
 
So I'm the true "casual" guy.  I'm not in it for big gains (although it'd be nice), I just want to fund a nice gaming rig that stays ahead of the casual gamer's curve in terms of performance.  So a pair of 6990s (or whatever the equivalent is when I finally get $600 or $700 worth of coins) will be my next purchase, and then we'll see after that. :)
 
I don't begrudge the hardcore miners, shit if I was single I'd be doing exactly that.  So if you're in a boat similar to mine, just get what you want, and don't feel bad.  If the bitcoin economy crashes, you still have a nice gaming rig for enjoyment.  :)

Don't take this the wrong way, but I've never understood how a guy could let his wife control the finances of the household. Even if she does the budget and bills how can you put your manhood in a drawer and have her dictate what you do with the money you make from work? My wife and I have always had separate finances. It keeps things really stable because I make a lot more than she does (about 3x) and I spend my free money on all kinds of toys, she spends her money on girl things, and neither of us can bitch and moan about what the other person is spending money on. I pay the bills and she gives me a percentage of the total monthly cost of living (rent, food, heat, electric, etc) which we determine by the income distribution. So basically, I pay 3/4 of the bills and she pays 1/4 because I make 3/4 of the household income. Everyone wins and no one has to limit what toys they are "allowed" to buy. I strongly recommend this method, it makes for a very respectful and stable relationship.

Adopted

I keep trying to get her to adopt that method, too, but honestly, we both recognize that without checks and balances, we'd probably have no money tied up in savings.  At least this way we have some back-up money (and we have children, so that eats up a ton of money). 
 
Without this method, I'd spend my extra cash on strippers and weed ;)

Why not a joint savings account? What me and my former partner used to do was to put the same amount into a joint account. It's not a huge sum but even if you do $200 each, that would be an ok $4.8K every year to deal with any emergencies. Taking any money out requires both signature so can't cheat. As to why equal instead of a percentage of our salary? Well, makes for less arguments when you have to split.

Then the rest of your money after paying off shared expenses, you can each get to spend however you want.

keep in mind 95% of the population is absolutely *retarded* about managing finances.

+1

Anyone who pays 15% (or more) interest on a credit card balance is pretty bad with money. And that's a *lot* of people.
It's even worse if they charged up stuff because it was "on sale", not realizing they'll pay much more for it in the long run.

Yeah, I know what you mean. I just finished paying off 24K of credit cards this year and got out of my house via short sale. Feels good to be free. FREE!!!! HAHAHAHAHA! NO MORE DEBT!! :D