Should you undermine? (OBSOLETE)

[Moser]

Many people see in the Bitcoins and, more precisely, in mining a hen from the golden eggs that can be used to generate money from nothing. 
This is not true: if it is undeniable that mining make bitcoins, you must always remember that computer calculation is not free: the cost is primarily represented by the additional electric current used by the computer to calculate, and secondly by wear to which the hardware meets. Finally, we must not neglect the commitment necessary to make everything work properly and to keep it functioning.
The sum of these components define the cost we have incurred to produce our bitcoins by mining. If the final price is lower than the market price, mining is advantageous. If it is lower, it is disadvantageous and it is therefore advisable to buy BTCs directly on the market rather than undermine them. 
Let's analyze separately the components of the cost of mining: 

Electricity
The mining process requires computational power, and to generate it the computer absorbs electrical energy. The amount of bitcoin that is generated with a kilowatt hour of electricity depends on the hardware used and on the level of current mining difficulty. The latter is a number that varies (generally increases) every two weeks or so and which represents how difficult it is to find the blocks, and can be read here . Knowing that value, to know how many BTC per kilowatt hour can be generated with a given hardware, you can use the formula "predigested" below: 

BTC / KWh = 41'911 * MHJ / difficulty

(this formula is valid in the ideal scenario: no pool fee, stales = 0, 100% uptime and in general no inefficiency.The only current consumed by the video card is taken into account) 

where MHJ is the MegaHashes / Joule value typical of each device used to undermine and recoverable on mining hardware comparison

With the current difficulty at 09/19/11 of 1'755'425, here are the BTC / KWh for some reference hardware. I have reported, in addition to the values already mentioned, the cost of the current necessary to make 1 BTC assuming 0.2 € per KWh and the net gain for a mined BTC, or the difference between the value of 1 BTC and the cost calculated before, assuming € 4 per BTC.
 

_______Guy_______Description___MHJ____BTC / KWh__ Cost for 1 BTC__Gain for 1 BTC__Good net daily_

Intel Core i5 650 CPULow power0.10.0024€ 83.3€ 79.3-0.36 €

Intel Core i7 950 CPUHigh power00:250006€ 33.3€ 29.3-0.34 €

NVIDIA GTX570 GPU0.50012€ 16.6-12.6 €-0.58 €

ATI HD 4870 GPUAti dated0.750016€ 12.5-8.5 €-0.73 €

ATI HD 6850 GPUAti recent low power1.400336.1 €-2.1 €-0.29 €

ATI HD 6970 GPUAri recent high power1.850044€ 4.5€ 0.5-0.11 €

From the table above, it can be seen that mining is, by calculating the only cost of electricity, economically at a loss in every possible scenario. 

Wear
This item is, unlike current consumption, extremely difficult to evaluate and to account for. The principle is that mining, increasing the energy consumption of the computer, causes an increase in the operating temperatures of the same, and with it a whole series of phenomena that can lead to reduction of the operational life, malfunctions, failures or even burns of the components with non-indifferent risks.
Not being able to evaluate the influence of this item, we must take this into account in a statistical sense: undermining on the PC exposes the hardware to a probability of failure and malfunctions greater than that which would occur in the absence of the load due to the same, and the entity the increase in this probability is greater the greater the temperatures at which the components inside the computer arrive (video card, motherboard, CPU, power supply, hard disks, ...). Be aware of it and do not assume that your hardware will not have problems. In any case it is STRONGLY DISCONFECT mined on laptops or computers with limited ventilation (barebones, mediacenter, ...) 

Uptime
in most calculations it is used to think that the PCs dedicated to mining are switched on 24h / 24 7g / 7. From experience I say that this does not happen NEVER: interventions on the PC, problems with the internet connection, interruption of electricity, freezes, failures, malfunctions of the pool etc. they reduce, sometimes significantly, the time when PCs actually undermine. Personally, in a protective way, in my calculations I consider an uptime of 80%. This happens especially in the early days, where you spend a lot of time refining the PC to squeeze it to the best while maintaining a certain reliability. 

Conclusion
Although mining may seem like an easy way to make money with little effort, the reality is very different. Considering the consumption of electricity only, it can be concluded that in Italy, due to the high cost of electricity in relation to other countries, the mining operation is currently in a net loss. 
Not only that: even if you accept to undermine at a loss, we must take into account the reduction of life to which the hardware will inevitably meet. 

To put it short: at the moment, generating bitcoins by mining is not absolutely convenient. . At the same money, it is much cheaper to buy bitcoins directly on the market than to produce them by undermining. In thisthread there is the testimony of those who tried to seriously undermine Italy, and the discomforting result.