Setting up a farm?

[SgtSpike]

Just curious what thoughts you all had on the best way to go about setting up an initial single computer farm, to later be expanded.  I am trying to keep initial investment costs down until the hardware has paid for itself, then continue expanding.  Looking to spend... oh, maybe $600 max?

Right now, I'm thinking AMD-based, with a good PSU, and a couple of 5850's.  Ram doesn't matter, and processor shouldn't matter (right?), so probably just whatever is cheapest that will run the computer on both those counts.  But is there a more recommended setup?

The reason I say 5850's is because they currently hold the crown for MH/s vs initial cost.  You get 250 MH/s for spending only $156.  They are also pretty good on the MH/s generated per kwh of electricity.  Not the best (the 6990's take that crown), but only about 20% worse than the best.

Obviously, the issue not taken into account there is that you can only fit so many cards onto a single motherboard, so that would increase the price/MH/s vs a higher end card, like a 6990, that could potentially run much more MH/s on a single motherboard.  I haven't really taken this into account yet, since the price of a "base" machine could vary a good deal even just from different PSU's for different sets of video cards.

Anyway, enough with the rambling.  What sort of setup should I go for with $600 to spend?

Oh, and also, how hard would it be to set this up on linux?  Especially for a complete linux n00b (I've installed it on a couple machines, and browsed the web, and that's about it).  Not having to purchase a license of Windows for every rig I start would also help keep costs down.

[gigabytecoin]

Instead of buying 4 5850s... why not simply buy 1 5970 for $500 used and maybe buy a $70 Mobo + CPU combo...

If you are going to create a "farm" then you will require a motherboard with multiple pcie slots which will cost multiple hundreds of dollars... just for the motherboard.

[SgtSpike]

Instead of buying 4 5850s... why not simply buy 1 5970 for $500 used and maybe buy a $70 Mobo + CPU combo...

If you are going to create a "farm" then you will require a motherboard with multiple pcie slots which will cost multiple hundreds of dollars... just for the motherboard.

Because 1 5970 = roughly 550 MH/s, and 4 5850's = roughly 1000 MH/s.

Motherboards with 4 PCIe slots can be had for $140.  In fact, I priced out an entire base system (no video cards) capable of running 4 video cards at $397.  So about $1000 in hardware would be getting me 1000 MH/s.

[gigabytecoin]

Instead of buying 4 5850s... why not simply buy 1 5970 for $500 used and maybe buy a $70 Mobo + CPU combo...

If you are going to create a "farm" then you will require a motherboard with multiple pcie slots which will cost multiple hundreds of dollars... just for the motherboard.

Because 1 5970 = roughly 550 MH/s, and 4 5850's = roughly 1000 MH/s.

Motherboards with 4 PCIe slots can be had for $140.  In fact, I priced out an entire base system (no video cards) capable of running 4 video cards at $397.  So about $1000 in hardware would be getting me 1000 MH/s.

You will need to buy some extension cables for those 4 cards probably since they will be too close together on the motherboard by itself. (They would get too hot side by side.)

I will post pics of my setup in another thread I have going once mine is up and running.

[bitjet]

Instead of buying 4 5850s... why not simply buy 1 5970 for $500 used and maybe buy a $70 Mobo + CPU combo...

If you are going to create a "farm" then you will require a motherboard with multiple pcie slots which will cost multiple hundreds of dollars... just for the motherboard.

Because 1 5970 = roughly 550 MH/s, and 4 5850's = roughly 1000 MH/s.

rrrr 1 5970 = ~720mhps. But good luck finding one for $500

I've been debating weather or not to buy a 4 pci-e mobo.

Tonight I bought a 2 slot mobo (mobo and cpu ~ $85) im going to put 2x5870's in there giving me an extra ~790mhps.. but maybe in the near future if I can get an investor that wants to make a 10% return over 5 months I can purchase another mobo for 4x5870 and put 2x6990 or 5970's in this mobo. I wont be buying any cases!

[SgtSpike]

Instead of buying 4 5850s... why not simply buy 1 5970 for $500 used and maybe buy a $70 Mobo + CPU combo...

If you are going to create a "farm" then you will require a motherboard with multiple pcie slots which will cost multiple hundreds of dollars... just for the motherboard.

Because 1 5970 = roughly 550 MH/s, and 4 5850's = roughly 1000 MH/s.

Motherboards with 4 PCIe slots can be had for $140.  In fact, I priced out an entire base system (no video cards) capable of running 4 video cards at $397.  So about $1000 in hardware would be getting me 1000 MH/s.

You will need to buy some extension cables for those 4 cards probably since they will be too close together on the motherboard by itself. (They would get too hot side by side.)

I will post pics of my setup in another thread I have going once mine is up and running.

Mmmm, good point.  Might just be more economical to set up dual-card rigs then... PSU and motherboard both would be cheaper.  About $250 for a baseline two-card rig, and $400 for a baseline four-card rig.  Only saves $100, and might be more hassle with setup and maintenance.

Instead of buying 4 5850s... why not simply buy 1 5970 for $500 used and maybe buy a $70 Mobo + CPU combo...

If you are going to create a "farm" then you will require a motherboard with multiple pcie slots which will cost multiple hundreds of dollars... just for the motherboard.

Because 1 5970 = roughly 550 MH/s, and 4 5850's = roughly 1000 MH/s.

rrrr 1 5970 = ~720mhps. But good luck finding one for $500

I've been debating weather or not to buy a 4 pci-e mobo.

Tonight I bought a 2 slot mobo (mobo and cpu ~ $85) im going to put 2x5870's in there giving me an extra ~790mhps.. but maybe in the near future if I can get an investor that wants to make a 10% return over 5 months I can purchase another mobo for 4x5870 and put 2x6990 or 5970's in this mobo. I wont be buying any cases!

Hmmmm, 5870's get 395MH/s?  And 5970's get 720MH/s?  Are you assuming overclocks?  Or is this page just completely wrong?  https://en.bitcoin.it/wiki/Mining_hardware_comparison

Also, I've searched and searched and searched... what exactly do the -f and -w switches do?

[SgtSpike]

Comparing the 5850 and the 5870...

5850 can be had for $157 shipped.
5870 can be had for $268 shipped, from a reputable seller (a few lower-priced ones that I don't necessarily trust).

5850 can do 292 MH/s at stock speeds on poclbm.
5870 can do 380 MH/s at stock speeds on poclbm.

5850 costs $0.54 per MH/s.
5870 costs $0.71 per MH/s.

It seems like, at least from a starting cost perspective, going the route of 5850's is a no-brainer.  UNTIL, you also consider the costs of a new system.  Assuming two cards per computer, it'd be $251 per system.

2x 5850 can be had for $251 + $157 x 2 = $565.00
2x 5870 can be had for $251 + $268 x 2 = $787.00

If you have to buy a computer to fit these cards, here are the new costs per MH/s.

2x 5850 costs $0.97 per MH/s
2x 5870 costs $1.04 per MH/s

So, the 5870's are still more expensive, considering initial cost, than the 5850's, even when you consider the cost for a new computer for every two cards.

I've done a lot of this analysis between various cards, and the 5850's always seem to win - at least at current video card prices.

Any other thoughts from you all?

[max in montreal]

Hi everyone this is my first post and comment...so bear with me.

I too am looking to start a farm, but I don't understand the math you are using to justify what card you are going to buy. I do not understand why you base it on how much the card costs, as opposed to how long for it to pay for itself. I guess it might be the same, but something in the math somewhere is bothering me...

Maybe I am having trouble explaining myself, but if you cheap out and worry about a card that is 50 bucks more, after the card is paid off, how much are you losing? If one card costs 50 bucks more but will make you 200 bucks more per month, why skimp?

[SgtSpike]

Hi everyone this is my first post and comment...so bear with me.

I too am looking to start a farm, but I don't understand the math you are using to justify what card you are going to buy. I do not understand why you base it on how much the card costs, as opposed to how long for it to pay for itself. I guess it might be the same, but something in the math somewhere is bothering me...

Maybe I am having trouble explaining myself, but if you cheap out and worry about a card that is 50 bucks more, after the card is paid off, how much are you losing? If one card costs 50 bucks more but will make you 200 bucks more per month, why skimp?

Because if I can buy 3 cards that make me 250MH/s each, instead of 2 cards that make me 300MH/s each for the same price, I'll go with the 3 cards.

Simplistic example, but basically, you want to go with the card with the best hash/$$ ratio, as long as you also include computer overhead with each card.

[max in montreal]

If the spread is huge I understand, but lets say the faster card is 20$, $30, or $40 more, when do we draw the line? Over time that extra spent on the faster card will bring in more money.

I think I would prefer to know how long it takes to pay it off.

[SgtSpike]

If the spread is huge I understand, but lets say the faster card is 20$, $30, or $40 more, when do we draw the line? Over time that extra spent on the faster card will bring in more money.

I think I would prefer to know how long it takes to pay it off.

Hey, its your money, do with it what you want.

EDIT:  Also, the card with the best MHash/$$ ratio will be the quickest in pay off.

[error]

Also consider the possibility that you will make more money by simply buying Bitcoins rather than mining.

[max in montreal]

Also, the card with the best MHash/$$ ratio will be the quickest in pay off.

I think this was the clarification I needed, thank you!