Bitcoin Forum

Bitcoin => Hardware => Topic started by: SebastianJu on March 31, 2013, 12:49:36 PM



Title: Buying FPGAs still useful?
Post by: SebastianJu on March 31, 2013, 12:49:36 PM
Hello,

i see there are still offered new FPGAs. 780MH/s for a price of $1280. And i think these units need around 40W.

When i put these data into: http://dev.bitcoinx.com/profit/ it looks like it will take almost a year until the buying price is back in. With more and more asics coming out it is possible that one never ever gets the invested bitcoins back.

So am i calculating wrong or how is it? I mean one has to get the invested bitcoins back at least. Otherwise he would be better with keeping the bitcoins and see their value rise.

Am i overlooked a point?

thanks!
Sebastian


Title: Re: Buying FPGAs still useful?
Post by: Isokivi on March 31, 2013, 01:02:10 PM
You are absoluteley right, I would suggest you redo the math with difficulty rising 10% every two weeks to see the even more bleak but realistic scenario.


Title: Re: Buying FPGAs still useful?
Post by: SebastianJu on March 31, 2013, 01:22:36 PM
What do you think whats a price for a fpga that is low enough to still get the investment back? I mean once the investment is back you can earn money if the bitcoin price is high enough to cover the power cost and have something more. But the hard part will be to get the investment back. Calculated in bitcoins. Otherwise holding bitcoins will be better.


Title: Re: Buying FPGAs still useful?
Post by: Isokivi on March 31, 2013, 01:30:50 PM
What do you think whats a price for a fpga that is low enough to still get the investment back? I mean once the investment is back you can earn money if the bitcoin price is high enough to cover the power cost and have something more. But the hard part will be to get the investment back. Calculated in bitcoins. Otherwise holding bitcoins will be better.
I don't believe there is such a fpga available, it's a hard time to invest in to mining equipment. I myself have fpga's running that paid for themselves about 2 months ago, after running ~8 months. I'd like to buy something, but nothing worth the risk is available atm.


Title: Re: Buying FPGAs still useful?
Post by: SebastianJu on March 31, 2013, 01:35:22 PM
I speak about used fpgas. What do you think would be a price (BTC/MH or $/MH) that is low enough to get the investment back even with the risk of more asics coming to mine?


Title: Re: Buying FPGAs still useful?
Post by: MaddestScientist on March 31, 2013, 01:53:02 PM
250MH/s or higher per BTC  ;D
 
I speak about used fpgas. What do you think would be a price (BTC/MH or $/MH) that is low enough to get the investment back even with the risk of more asics coming to mine?


Title: Re: Buying FPGAs still useful?
Post by: SebastianJu on March 31, 2013, 01:55:09 PM
250MH/s or higher per BTC  ;D
 
I speak about used fpgas. What do you think would be a price (BTC/MH or $/MH) that is low enough to get the investment back even with the risk of more asics coming to mine?

Thats very few. And way more than all the used fpgas are sold here in the forum. Looks like i will stop looking after fpgas. Doesnt make sense if i would earn more when i simply hold my bitcoins instead investing them.


Title: Re: Buying FPGAs still useful?
Post by: .m. on March 31, 2013, 02:01:58 PM
Hi, what do you think about this one ?
Virtex-7 2000T: Designed with ASIC Prototyping and Emulation in Mind - FPGA enabled by Stacked Silicon Interconnect (SSI) technology delivers 2 million logic cells, 6.8 billion transistors in 28 nm design.
Around 20W @ 100 MHz  (3600 8 bit processing elements consumed 85% chip capacity providing 180 000 MIPS)

http://www.xilinx.com/applications/asic-prototyping/index.htm (http://www.xilinx.com/applications/asic-prototyping/index.htm)

oops - do they really cost 5000 USD each ?


Title: Re: Buying FPGAs still useful?
Post by: Isokivi on March 31, 2013, 02:35:55 PM
Hi, what do you think about this one ?
Virtex-7 2000T: Designed with ASIC Prototyping and Emulation in Mind - FPGA enabled by Stacked Silicon Interconnect (SSI) technology delivers 2 million logic cells, 6.8 billion transistors in 28 nm design.
Around 20W @ 100 MHz  (3600 8 bit processing elements consumed 85% chip capacity providing 180 000 MIPS)

http://www.xilinx.com/applications/asic-prototyping/index.htm (http://www.xilinx.com/applications/asic-prototyping/index.htm)

oops - do they really cost 5000 USD each ?


I wouldnt know if that could mine or not. What I know for sure that the needed bitstream does not exist and making one is no trivial task. See here to what lenghts the community had to go inorder to get the cairnsmores for example utilized when the hardware manifacturer was struggling to provide a useable bitstream: https://bitcointalk.org/index.php?topic=94317.0


Title: Re: Buying FPGAs still useful?
Post by: Bogart on March 31, 2013, 02:54:14 PM
For some reason the used FPGA market is really hot right now.  Finding them is hard.

I think it has a lot to do with the soaring bitcoin market value.  A ton of noobs are jumping in now, and they want to buy a miner.  Any miner.

They sure as hell can't get ASICs easily, so if they can get an FPGA, they'll pwn it up.  Beyond that, they're snatching up GPUs, 'cuz that's what they can get.

If you don't believe in the future profitability of your FPGA vs what you could make selling it, now might be a good time to sell while the market is strong.


Title: Re: Buying FPGAs still useful?
Post by: SebastianJu on March 31, 2013, 03:03:24 PM
For some reason the used FPGA market is really hot right now.  Finding them is hard.

I think it has a lot to do with the soaring bitcoin market value.  A ton of noobs are jumping in now, and they want to buy a miner.  Any miner.

They sure as hell can't get ASICs easily, so if they can get an FPGA, they'll pwn it up.  Beyond that, they're snatching up GPUs, 'cuz that's what they can get.

If you don't believe in the future profitability of your FPGA vs what you could make selling it, now might be a good time to sell while the market is strong.

I mean mining with fpgas and gpus are profitable now... if you already own them. But the thing is that the rising value of btc and difficulty will lead to mined bitcoins that are worth more but you cant mine as many bitcoins you had to invest with it, because the rising difficulty will make this impossible. That means keeping the bitcoins is the better investment. So at the end its probably a calculation error by the buyers or they dont know what the rising difficulty will do.
You think thats right, yes?


Title: Re: Buying FPGAs still useful?
Post by: gyverlb on March 31, 2013, 03:52:00 PM
I mean mining with fpgas and gpus are profitable now... if you already own them. But the thing is that the rising value of btc and difficulty will lead to mined bitcoins that are worth more but you cant mine as many bitcoins you had to invest with it, because the rising difficulty will make this impossible. That means keeping the bitcoins is the better investment. So at the end its probably a calculation error by the buyers or they dont know what the rising difficulty will do.
You think thats right, yes?

Currently you get ~0.2BTC each month for 100MH/s. This will slowly but regularly go down as ASICMiner and Avalon add hashrate on the market. In the coming months there might be several other ASIC players : 100th (scheduled for June/July) and BFL (if they manage to solve their power usage problems there's still at least one month before they can ship), maybe some others.

As FPGAs have next to no resale value if you pay more than 3 months worth of mining at current difficulty there's little chances you'll see all your BTC back.

Based on these assumptions: quad Spartan6 (Cairnsmore1) with 800MH/s might be worth 4.8 BTC (including shipping/taxes), dual Spartan6 (Icarus/x6500/...) 2.4BTC.

Anything more is probably wasted Bitcoins.


Title: Re: Buying FPGAs still useful?
Post by: SebastianJu on March 31, 2013, 04:33:39 PM
I mean mining with fpgas and gpus are profitable now... if you already own them. But the thing is that the rising value of btc and difficulty will lead to mined bitcoins that are worth more but you cant mine as many bitcoins you had to invest with it, because the rising difficulty will make this impossible. That means keeping the bitcoins is the better investment. So at the end its probably a calculation error by the buyers or they dont know what the rising difficulty will do.
You think thats right, yes?

Currently you get ~0.2BTC each month for 100MH/s. This will slowly but regularly go down as ASICMiner and Avalon add hashrate on the market. In the coming months there might be several other ASIC players : 100th (scheduled for June/July) and BFL (if they manage to solve their power usage problems there's still at least one month before they can ship), maybe some others.

As FPGAs have next to no resale value if you pay more than 3 months worth of mining at current difficulty there's little chances you'll see all your BTC back.

Based on these assumptions: quad Spartan6 (Cairnsmore1) with 800MH/s might be worth 4.8 BTC (including shipping/taxes), dual Spartan6 (Icarus/x6500/...) 2.4BTC.

Anything more is probably wasted Bitcoins.

Ok, they are trade above these values. So i let it be and hope that it works better with avalon batch 3, where i ordered one 85GH Unit. I hope it will come in time and i get back my investment fast. I think its still a gamble depending on how many TH asicminer can put in. And in the case BFL manages to ship. But at least it looks better with such hardware even when the time of shipping is unsecure.