Bitcoin Forum

Other => CPU/GPU Bitcoin mining hardware => Topic started by: mrhobbeys on October 03, 2013, 12:25:34 AM



Title: Buying other miners used equipment?
Post by: mrhobbeys on October 03, 2013, 12:25:34 AM
A local miner (I assume) is dumping 50-100 5970s and 6990s on the market here. These are going to be sold from around $150-200 each and $300-400 each respectively. I have a couple of ASICs running but never really got fully into mining, other than burning up a few cheap ATI cards over the years and grabbing ASICs for the fun of it, I am thinking about buying these to run until I can get my hands on some of the bigger ASICs that are about to come out. Would you make the same call?


Title: Re: Buying other miners used equipment?
Post by: Xyver on October 07, 2013, 04:44:23 AM
Nope Nope Nope.

A 5970 consumes 200 watts and gives 700 megahashes.  You lose 24 cents per hour, assuming you pay $0.10 per kWh

A 6990 consumes 200 watts and gives ~750 megahashes.  You lose 22 cents an hour, assuming you pay $0.10 per kWh

So.... 50 of those loses you $11.50 every hour you run it, $23.00 for 100 of them.  Even with free power, you'd only make $12.50-$25.00 a day.

Plus you need to get all the hardware to run them, max you can get is 6 graphics card per computer, so you're looking at 9-17 computers to build.

AND, they've already been mining for ages, so the cards are probably old and worn out.


Title: Re: Buying other miners used equipment?
Post by: Wipeout2097 on October 07, 2013, 03:45:58 PM
Only if you want to undervolt the cards and mine more profitable alt-coins ...


Title: Re: Buying other miners used equipment?
Post by: kuusj98 on October 07, 2013, 05:41:51 PM
Only if you want to undervolt the cards and mine more profitable alt-coins ...
This, and: For god sakes don't buy more than 6, these cards are old and have worked theyr asses of so don't expect too much reliability of them.


Title: Re: Buying other miners used equipment?
Post by: uberdag on October 07, 2013, 06:56:12 PM
why wouldnt you use them for alt coins?


Title: Re: Buying other miners used equipment?
Post by: Eternity on October 08, 2013, 03:00:03 PM
Mine altcoins and trade them for btc


Title: Re: Buying other miners used equipment?
Post by: salfter on October 08, 2013, 03:17:04 PM
Nope Nope Nope.

A 5970 consumes 200 watts and gives 700 megahashes.  You lose 24 cents per hour, assuming you pay $0.10 per kWh

A 6990 consumes 200 watts and gives ~750 megahashes.  You lose 22 cents an hour, assuming you pay $0.10 per kWh

If you're mining Bitcoin with GPUs, you're doing it wrong. I have ~470 kH/s between a 6870 and a 7750, and they're still well in the black even at ~11¢/kWh.  The various scrypt altcoins lately have been at least 5x as profitable as Bitcoin, if not more.  You mine Bitcoin (and SHA-256 altcoins) only with hardware that can't mine other types of altcoins: ASIC and FPGA miners.


Title: Re: Buying other miners used equipment?
Post by: fattypig on October 10, 2013, 01:08:12 PM
A local miner (I assume) is dumping 50-100 5970s and 6990s on the market here. These are going to be sold from around $150-200 each and $300-400 each respectively. I have a couple of ASICs running but never really got fully into mining, other than burning up a few cheap ATI cards over the years and grabbing ASICs for the fun of it, I am thinking about buying these to run until I can get my hands on some of the bigger ASICs that are about to come out. Would you make the same call?

The price is too expansive, get 7950, 7970 and 7990 from newegg. It should be cheaper this coming week due to the launch of R7 and R9


Title: Re: Buying other miners used equipment?
Post by: klondike_bar on October 10, 2013, 06:20:01 PM
Nope Nope Nope.

A 5970 consumes 200 watts and gives 700 megahashes.  You lose 24 cents per hour, assuming you pay $0.10 per kWh

A 6990 consumes 200 watts and gives ~750 megahashes.  You lose 22 cents an hour, assuming you pay $0.10 per kWh

So.... 50 of those loses you $11.50 every hour you run it, $23.00 for 100 of them.  Even with free power, you'd only make $12.50-$25.00 a day.

what the hell are you talking about? your math is off by a factor of 10.

a kWh means 1000w used for a full hour. a 200w card uses 0.2 kWh = 2.2c of electricity at $0.10/kWh

used for scrypt mining litecoins, a 5970 and 6990 both produce around 700khash/s, which is over a dollar per day, minus roughly $0.30 meas a profit of around 60-80 cents per day per card. Assuming difficulty stays fairly constant (unlikely), it would take a year or more to pay off costs. In reality, it will likely take closer to 1.5-2years if difficulty rises at a minimal pace


Title: Re: Buying other miners used equipment?
Post by: CMMPro on October 11, 2013, 02:20:51 AM
Used computer electronics are not worth anything. Especially if this person has 50-100 of them.
Try $15-20 each card....or about 1/10 of what they are asking.




Title: Re: Buying other miners used equipment?
Post by: klondike_bar on October 11, 2013, 02:31:02 AM
Used computer electronics are not worth anything. Especially if this person has 50-100 of them.
Try $15-20 each card....or about 1/10 of what they are asking.

not true. at $15 the card could pay for itself (and power use) within a month of mining litecoin

that said, a used [from mining] 5970 and 6990 should only cost 150 and 200 respectively


Title: Re: Buying other miners used equipment?
Post by: Xyver on October 11, 2013, 06:18:51 AM
Nope Nope Nope.

A 5970 consumes 200 watts and gives 700 megahashes.  You lose 24 cents per hour, assuming you pay $0.10 per kWh

A 6990 consumes 200 watts and gives ~750 megahashes.  You lose 22 cents an hour, assuming you pay $0.10 per kWh

So.... 50 of those loses you $11.50 every hour you run it, $23.00 for 100 of them.  Even with free power, you'd only make $12.50-$25.00 a day.

what the hell are you talking about? your math is off by a factor of 10.

a kWh means 1000w used for a full hour. a 200w card uses 0.2 kWh = 2.2c of electricity at $0.10/kWh

used for scrypt mining litecoins, a 5970 and 6990 both produce around 700khash/s, which is over a dollar per day, minus roughly $0.30 meas a profit of around 60-80 cents per day per card. Assuming difficulty stays fairly constant (unlikely), it would take a year or more to pay off costs. In reality, it will likely take closer to 1.5-2years if difficulty rises at a minimal pace

Whoops, last time I trust online calculators :P  I was just throwing numbers into http://www.bitcoinx.com/profit/


Title: Re: Buying other miners used equipment?
Post by: cowandtea on October 12, 2013, 09:02:14 AM
No, no and no.

First, the price is not reasonable and I believe there is no more warranty. Good luck..


Title: Re: Buying other miners used equipment?
Post by: Eternity on October 28, 2013, 10:39:22 AM
Those cards are useless to mine btc


Title: Re: Buying other miners used equipment?
Post by: high110 on October 28, 2013, 12:00:27 PM
http://www.ebay.com/sch/i.html?_trksid=p3984.m570.l1313.TR6.TRC1.A0.Xbitcoin+mining&_nkw=bitcoin+mining&_sacat=0&_from=R40

Even the miners on ebay are better... as in they will provide you with GHS/dollar instead of the old mining cards.


Title: Re: Buying other miners used equipment?
Post by: rampalija on October 31, 2013, 12:15:18 AM
GPUs are good way to start mining now. If you have a free power ofcourse


Title: Re: Buying other miners used equipment?
Post by: Xyver on October 31, 2013, 05:31:20 AM
GPUs are good way to start mining now. If you have a free power ofcourse

Lies! Not for BTC!  Maybe for alt coins.


Title: Re: Buying other miners used equipment?
Post by: rampalija on October 31, 2013, 03:27:12 PM
GPUs are good way to start mining now. If you have a free power ofcourse

Lies! Not for BTC!  Maybe for alt coins.

lool  i meant the altcoin, not BTC