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Bitcoin Currency and GPU Mining Performance Comparison

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What is a Bitcoin?

This article looking at Bitcoins and the performance of various GPUs with mining them was really a big team effort at PC Perspective.  Props goes out to Tim Verry for doing the research on the process of mining and helping to explain what Bitcoins are all about.  Ken Addison did a great job doing through an alottment of graphics cards running our GUIMiner and getting the data you will see presented later.  Scott Michaud helped with some graphics and imagery and I'm the monkey that just puts it all together at the end.

** Update 7/13/11 **  We recently wrote another piece on the cost of the power to run our Bitcoin mining operations used in this performance article.  Based on the individual prices of electric in all 50 states of the US, we found that the cost of the power to run some cards exceeded the value of the Bitcoin currency based on today's exchange rates.  I would highly recommend you check out that story as well after giving this performance-based article a thorough reading.  ** End Update **

A new virtual currency called Bitcoin has been receiving a great deal of news fanfare, criticism and user adoption. The so called cryptographic currency uses strong encryption methods to eliminate the need for trust when buying and selling goods over the Internet in addition to a peer-to-peer distributed timestamp server that maintains a public record of every transaction to prevent double spending of the electronic currency. The aspect of Bitcoin that has caused the most criticism and recent large rise in growth lies in is its inherent ability to anonymize the real life identities of users (though the transactions themselves are public) and the ability to make money by supporting the Bitcoin network in verifying pending transactions through a process called “mining” respectively. Privacy, security, cutting out the middle man and making it easy for users to do small casual transactions without fees as well as the ability to be rewarded for helping to secure the network by mining are all selling points (pun intended) of the currency.

When dealing with a more traditional and physical local currency, there is a need to for both parties to trust the currency but not much need to trust each other as handing over cash is fairly straightforward. One does not need to trust the other person as much as if it were a check which could bounce. Once it has changed hands, the buyer can not go and spend that money elsewhere as it is physically gone. Transactions over the Internet; however, greatly reduce the convenience of that local currency, and due to the series of tubes’ inability to carry cash through the pipes, services like Paypal as well as credit cards and checks are likely to be used in its place. While these replacements are convenient, they also are much riskier than cash as fraudulent charge-backs and disputes are likely to occur, leaving the seller in a bad position. Due to this risk, sellers have to factor a certain percentage of expected fraud into their prices in addition to collecting as much personally identifiable information as possible. Bitcoin seeks to remedy these risks by bringing the convenience of a local currency to the virtual plane with irreversible transactions, a public record of all transactions, and the ability to trust strong cryptography instead of the need for trusting people.

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There are a number of security measures inherent in the Bitcoin protocol that assist with these security goals. Foremost, bitcoin uses strong public and private key cryptography to secure coins to a user. Money is handled by a bitcoin wallet, which is a program such as the official bitcoin client that creates public/private key pairs that allow you to send and receive money. You are further able to generate new receiving addresses whenever you want within the client. The wallet.dat file is the record of all your key pairs and thus your bitcoins and contains 100 address/key pairs (though you are able to generate new ones beyond that). Then, to send money one only needs to sign the bitcoin with their private key and send it to the recipient’s public key. This creates a chain of transactions that are secured by these public and private key pairs from person to person. Unfortunately this cryptography alone is not able to prevent double spending, meaning that Person A could sign the bitcoin with his private key to Person B, but also could do the same to Person C and so on. This issue is where the peer-to-peer and distributed computing aspect of the bitcoin protocol come into play. By using a peer-to-peer distributed timestamp server, the bitcoin protocol creates a public record of every transaction that prevents double spending of bitcoins. Once the bitcoin has been signed to a public key (receiving address) with the user’s private key, and the network confirms this transaction the bitcoins can no longer be spent by Person A as the network has confirmed that the coin belongs to Person B now, and they are the only ones that can spend it using their private key.

Keep reading our article that details the theories behind Bitcoins as well as the performance of modern GPUs in mining them!  

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The privacy and anonymity afforded by the bitcoin protocol has received flak recently due to the currency being used to purchase illegal drugs and other products online. The US government has seen a number of members speak out against the currency because of the illegal drug involvement and taxation implications. However, bitcoin is not the only currency that is used by a number of people for illegal uses, and it is certainly not representative of a majority of illegal usage. Regardless of the relatively small number of illegal uses, the privacy afforded by bitcoin is not inherently a bad thing. As the Internet equivalent to a local currency such as cash, bitcoin is able to facilitate a much higher level of anonymity than other currencies used online. The privacy implications are not only good for those mis-using it for nefarious purposes; it is actually a good thing for legal transactions because sellers do not need to collect nearly as much personally identifiable information in order to trust the buyer enough to go through with the sale. Traditionally, telephone numbers, addresses, financial information, and other personal information has been required in order for even the most mundane transactions over the Internet as sellers needed to protect themselves as much as possible from fraud.

July 13, 2011 | 06:22 PM - Posted by Florian (not verified)

I think it is your responsibility to deter readers more actively from investing in hardware in order to conduct bitcoin mining and distance yourselves from those activities. It is easy for people to understand that they can make money from computing power, but it takes some very careful reading to understand that by design, this whole enterprise will become less and less profitable over time. So I think it would be better to put the emphasis of the article on parallel computing performance and to use bitcoin merely for illustrative purposes. At the very least, you should factor in the energy costs in your profitability analysis, but in my opinion, calculating projections is misleading and even deceptive, given the facts about Bitcoin (see below).

So my warning here:
!!! WARNING !!!
===================================================
Investing in hardware in order to engage in bitcoin mining is a highly risky and quite possibly loss-making idea!
The calculations of "Days to payoff" and "1 year profit" in this article are misleading: Not only is the rate of bitcoin creation is deliberately being slowed as the total number of bitcoins approaches 21 millions, it is also getting more and more difficult to accumulate enough computing power as the number of participants in bitcoin mining is increasing (as people reading this article and others will start setting up their own mining operation). The only effect countering this deterioration in profitability would be an increase in the dollar value of the bitcoin, which is uncertain and unpredictable.
====================================================

July 13, 2011 | 07:25 PM - Posted by Ken Addison

Oh hey look, that's already in the article..

"Please keep in mind that we understand that these values will change over time not only because of the exchange rate differences but because your ability to mine Bitcoins will slow down over time as the algorithm to find coins becomes more and more complex as the network hashing power increases. Read over the first two pages of the article again to understand WHY this happens but just know the results you will see below are based on an instance in time during this writing process!"

July 13, 2011 | 07:52 PM - Posted by Anonymous (not verified)

I hope this is a dumb question, but what prevents a virus from creating a mining botnet?

July 13, 2011 | 08:27 PM - Posted by Anonymous (not verified)

Nothing really. Plus a virus which specifically only attempted GPU mining would be alot easier to hide in the windows environment since most users are unlikely to be monitoring GPU usage levels when simply web browsing etc.

A virus which intelligently slowed its mining attack if the user was trying to do something GPU intensive (gaming), in order to hide the system use and keep the user from noticing massive in-game slowdown, could likely mine away unnoticed.

I do not fully understand the setup in regards to mining as a pool though, which is what you would ultimately want all your zombied systems to do. I guess it is probably not 'that' difficult to setup a pooling setup given how many continue popping up, plus presumably someone writing a virus specifically targetted at hijacking GPU cycles is probably a decent enough coder.

July 14, 2011 | 05:20 PM - Posted by Tim Verry

There have actually been some botnets (that have since been shut down) mining for pools; however, they were thousands of computers using the CPUs to mine as access to the GPU hardware is more difficult/would require more end user cooperation to get that botnet software installed and running, AFAIK.

July 13, 2011 | 08:27 PM - Posted by Anonymous (not verified)

This test didn't use DiabloMiner, so it's automatically invalid.

July 14, 2011 | 03:37 AM - Posted by Sturle (not verified)

What price did you use for power in your profit calculations? At 500W for a simple 6990 system, total power consumption in a year of 24/7 use will be 4380 kWh. Your profit after one year will be negative if your price for power is more than about 35 cents, assuming constant difficulty. All Nvidia cards will operate at a loss unless your power is very cheap or free.

Difficulty is about 1000 times larger now than half a year ago, btw. Power cost has become the most important factor in mining profitabilty.

July 14, 2011 | 06:49 AM - Posted by Ryan Shrout

You should check out the second article for a host of details on that topic:

http://www.pcper.com/reviews/Graphics-Cards/Bitcoin-Mining-Update-Power-...

July 14, 2011 | 05:32 AM - Posted by Europe (not verified)

For european readers, the power use is a bit more important. 1kwh of power costs on average around 0.25 euro.
Which means a system like the beast (using 1kw of power) will cost you 0.25*24*365 = 2190 euros per year in electricity.
The beast yearly produces 3637 dollar equivalent bit coins, which is about 2584 Euros.

That means it will effectively only produce 394 euros. And that is not counting the cost of buying the system.

July 14, 2011 | 10:25 AM - Posted by Acejam (not verified)

A 6990 in the default BIOS position should generate 330 MHash/s PER core. That's 660 MHash/s per card. I'm not sure why, but your card is showing a much slower speed on one of the cores. (~285.3 MHash/s)

Switch the BIOS switch to position 2 and you'll be at 360-375 MHash/s per core.

You also seem to be missing the most basic flags for GUIMiner running poclbm: -v -w128

July 14, 2011 | 11:13 AM - Posted by Anonymous (not verified)

Does anyone see this as an AMD ATI scam? I smell so O_o

July 15, 2011 | 12:22 AM - Posted by Anonymous (not verified)

Your cpu usage is silly!
It's prolly the guiminer interface or something.
My 'rig' runs 350Mh/s on i7 2600k and HD6970 and rarely hits 4% cpu usage.
And that is while i run an active minecraft server and use the rig to watch videos and stuff (gets it to about 8% for SD video).
I'm using the Phoenix miner btw.

July 15, 2011 | 12:30 PM - Posted by Sc00bz (not verified)

"... maximum performance on a Core i7-2600K of 8 instructions x 4 cores x 3.4 GHz = 108.8 GigaInstructions."

It's 4 integer operations/instruction x 3 instructions/clock x 4 cores x 3.4 GHz = 163.2 GigaInstructions/second. AVX is 4 integer operations/instruction or 8 floating point operations/instruction. Each clock can issue up to 3 instructions if they don't depend on the answer of the previous instructions. The nice thing with AVX over SSE2 is AVX has instructions like a = b *operation* c vs a = a *operation* b for SSE2.

July 18, 2011 | 12:10 AM - Posted by Anonymous (not verified)

Great articles guys. thanks.

July 19, 2011 | 08:36 AM - Posted by Anonymous (not verified)

You DO know that there are single-slot water-cooled Radeon HD 6990 monstrosities out there, do you? 8 of these in a single system *head spins*...

July 19, 2011 | 01:52 PM - Posted by Anonymous (not verified)

This whole thing sounds kind of stupid.

July 21, 2011 | 06:06 PM - Posted by Bryan Clanton (not verified)

Who is this IDIOT slamming bit coins? Moron, the US government has nothing to do with the Federal Reserve Bank. It is owned by private individuals. Do you homework before your next show-n-tell.

July 21, 2011 | 06:07 PM - Posted by Bryan Clanton (not verified)

Who is this IDIOT slamming bit coins? Moron, the US government has nothing to do with the Federal Reserve Bank. It is owned by private individuals. Do you homework before your next show-n-tell.

July 22, 2011 | 09:48 PM - Posted by Jimmy (not verified)

Now i know why i can't find another 5850 to run crossfire with. The ones i do find are way overpriced now.

July 24, 2011 | 12:45 AM - Posted by Escalus (not verified)

I'm looking at testing out a very simple mining rig. If I get a Radeon 6XXX series GPU, would it make sense to use it on a Core 2 Duo system? Would the CPU be a bottleneck?

July 27, 2011 | 04:04 AM - Posted by Those Who Get it (not verified)

So your telling me you put a Virus on your computer that helps criminals launder money.
you let it operate through your GPU because there is no security there.
and you spend hundreds on hardware and power, for a experiment in social engeneering?
then you think that because 3 places are taking the hype of the bitcoin as a COUPON to sell you shit at 3 times the normal cost, that the bitcoin is therin a currency?

what do you think your GPU is really processing?
or does anyone think?

July 27, 2011 | 04:17 AM - Posted by Those Who Get it (not verified)

You just dont get it,
the GPU is processing YOU!
It is internally cyclicly redundant pre-processing your own non-trasnactions, into a multilevel advertising purchacing and marketing scheme.
If they do not enable the user with a journey, then there is no game to be played. There is no Corelation to alternative universal dimentional shifting of exchange goods in virtuality, when there still is nothing but virtuality in existance.
How do you perceive that something exist when one person tells you that it exist, and masses of people join that ONE person to confirm that it exists.
That is a singularity of the black hole variety.

October 12, 2011 | 05:54 AM - Posted by Anonymous (not verified)

Issue -problem guiminer with dual gpu card HD6870x2 powercolor. After creating new worker for the second Gpu, it still doesnt work 0 Mhashes the first gpu at 304 Mhashes clock at 970 Mhz 60% fan speed temp 74 degrees Celsius
flags -v -w128 -a4. Does anybody know how to setup this correctly , so that both gpu´s work at the same time thank you for helping me out.

December 15, 2012 | 09:45 AM - Posted by Anonymous (not verified)

This is all far too complicated for me. Can't you have a simple link to click on that will look at one's machine and say "yes" or "no"?

February 21, 2013 | 07:46 AM - Posted by Anonymous (not verified)

How do I buy the beast? Then after I buy, I would probably find a better more efficient system where?

July 14, 2013 | 08:40 PM - Posted by whitesites (not verified)

You guys really need to rerun this test using bitminter. I have the GTX 560 TI and I am getting 138 Mhps with that card. Also would really like to see how the new ATI 7xxx series cards perform.

November 6, 2013 | 07:24 PM - Posted by Anonymous (not verified)

is your 560ti a 448 core version or no? also are you only running 1 card or do you have a sli, tri-sli, or tri-sli with a fourth dedicated physics card?

kinda wonder what my ole x58 rig might pull off with its i7 980X cpu
3x GTX 560Ti 448 core GPU's
lowly 9600GT that is just in there as a dedicated PhysX processor

course I built it with a 1600 watt psu and the system doesn't pull enough juice to really even warm the power supply up LOL

September 6, 2013 | 06:41 PM - Posted by Anonymous (not verified)

Try this site, it may help you. Goodluck! http://btc.nubtektrx.us

November 22, 2013 | 01:27 PM - Posted by Ralph (not verified)

Has anyone considered solar power for the electricity? Take longer to recoup costs, but any analysis?
Ralph

December 26, 2013 | 03:47 AM - Posted by Anonymous (not verified)

hi
Iwant to have one accunt plz .
download sowftwer

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