Topic: What's your magic number? (or, Should I keep mining?) - page 2. (Read 8752 times)

Yeah, some resources are definitely shared.
For my machine it looks much more extreme:

Just CPU: 9.5 Mh/s
Just GPU: 85.5 Mh/s

Both: 68Mh/s(GPU)+9Mh/s(CPU)=77Mh/s - so it seems their competition for resources takes up some time. I got the highest M using GPU only.

Very useful post for those intending to get into mining and/or purchasing more hardware. As I'm using some existing equipment a while ago I calculated the extra power use as about $1 a day and just keep my eye on if it's profitible from time to time based on my BTC generated per day, not as though in my case having it running a week when it would have been cheaper to purchase is a particular financial disaster.

Besides it's coming into winter in Australia and I'm having a go at growing herbs inside, so if I stop mining it'll probably get too cold and kill my Thai Basil .

Don't forget that this is assuming that you sell your BTC at the exact rate that is used to calculate (BTC/USD), if you stop once your "Magic Number" falls below, you'll stop earning BTC. Essentially betting that BTC rates will not go up.

If enough people does this and pulls out, others that are still mining will get more for their shares since less share are distributed during the solving time.

Also, you're ignoring the fact that (if) you invested capital into buying hardware and have not compensated, those are just sitting around. AND if you're just waiting for the rates to go up, you won't have BTC to sell (assuming you sold them when you've got them) when they do and have to start mining for them.

But of course, during this 'downtime' it's obviously better to use your 'cost' to buy bitcoins instead that'd bring a different dynamic as people who are still mining would earn more BTC while people who are buying bitcoins are bringing the rates up.

The important question is then how long does it take for the rates to go up high enough for people to start selling/mining again, if it takes long enough, people who are mining might make more than those who are buying as the prices go higher. If this time period is too short then question is did you buy enough to cover what you've missed out.

Then again, this is assuming if the economy get's back up. if it doesn't, then those who invested into buying more than their 'cost' would lose more, while those mining will have BTC in their wallets and maybe those will worth something in the future after the collapse.

Just my 2 cents worth, I don't really know which is better or the real dynamic. I'm new and I just think that calling this a 'magic number' is over-reaching and it actually doesn't reflect enough of what goes on. It just shows that right at this point you're probably paying more for electricity than what you're mining. Not necessarily a decisive factor to stop operation altogether.

Just out of curiosity I did the calculations for my Netbook (HP Mini 311c) which has an Atom N270 and Nvidia ION chipset (Geforce 9400M - hell yeah, netbook with Dx10 and Cuda  ) while they have very low hash rates I was curious to see if the silly low power usage would counter that. The hash rate testing was performed in Ubuntu 11.04, using the SSE CPU Miner and Phoenix GPU miner.

I pay about £0.10 per kWh for power.

CPU:

Hashes at 1.52Mhash/s
Draws 5W at full load

GPU:

Hashes at 1.92Mhash/s
Draws 6W at full load

However when I tested this I noticed that they cannot do these hash rates while the other is loaded as they must share some of the same components in the ION chipset, the combined hash rate was only 2.52Mhash/s.

Once again discounting all extras such as the screen, HDD, speakers, etc, etc we get the following:

Just CPU: 2549.95
Just GPU: 2684.16
Combined: 1921.61

So in this case, surprisingly in theory it is technically profitable right now to using my netbook; however once the power used by everything else is factored in (29W maximum with screen on full brightness at 100% load) with the obscene low hash rates it is completely unfeasible.

that sounds about right, mining on any CPU is pretty much worthless, they are very inefficient.  mining on my 5GHz 2500K yields 8 Mhash/s where on my 6950 is 360 Mhash/s, ATI video cards are where its at, nVidia cards are about 5-10x slower due to their GPU architecture being more like a CPU than ATIs.  You can read about it on the bitcoin FAQ.  It doesn't sound like it would be worth it for you on either the CPU or GPU.

Based on the information here I can make a few of these estimates for your system under ideal circumstances.

Using the highly optimized SSE2 miner yours Q6600 should be able to do 11Mhash/s using all 4 cores for 105W, now if you only want to use two cores then we can roughly half all of those numbers for the total calculation (very roughly)

So thats 5.5Mhash/s @ 52.5W.

Next we add your graphics card in, which is sadly only capable of about 3.37 Mhash/sec at a power usage of 50W.

So the following magic number apply for you (assuming no other power use, which of is not true):

Just CPU = 585.83
Just GPU = 376.90
Both CPU & GPU = 518.43

Now as you can see I'm afraid even under ideal circumstances, not counting the cost of power for your other components/cooling/peripherals you are well below the break-even point of around 700 shares/USD right now, with your GPU being far more inefficient than your CPU.

I'm new to this (just saw the write-up on lifehacker), and curious if this would be profitable. I did a test run on my q6600 using only two cores and got 2269 khash/s. Now at .14 kWh and a 450W ps I got .008391698 as my magic number. Now assuming my math was right (.000233*2.269)/(.45*.14) I should just forget it.

My questions are:
1. Did I get the math right?
2. Would using a mining program vs bitcoin make a difference?
3. Would using a mining program on my 9400GT card make it worthwhile?

Thanks for the help.

If mining for a pool that has a fee one should use an adjustment for the reward: For example if the fee is 2% (like Slush's one) the reward should be 49 not 50.

Values for me:

M=317
Threshold=275

So I should mine even if my comp has nothing else to do.  

Careful with the units.

(1) 1.44 Gh/s is 0.00144 Th/s, not 1440. So divide by 1,000,000.

(2) Your hashrate is a rate per second, but your power usage is a rate per hour. So multiply by 3600.

(3) I'm assuming by "KW/hr" you mean "dollars/kWh" (or whatever currency you prefer).

This gives you an actual magic number of 16,043.4286 shares/dollar.


You're good until the difficulty divided by (50x the exchange rate) reaches 16,043.4286. But this number is falsely precise and you'd be better off looking out for the number 16,000.

1.44 Gh/s 820Watts .092 KW/hr

(1 440 * 233) / (.820 * .092) = 4 447 507.95

So I'm good until the difficulty reaches 4,447,507.95 ?

Subsidy is another name for the block reward. I prefer the term subsidy because it implies that it is a temporary measure while the network is smaller and transaction fees are not a sufficient enticement for mining.

few months/weeks later mining can't be profitable even with GPU.
and after hash change[SHA256 isn't bulletproof enough, IMO], even CPU's mining goes in history too.

I just noticed something: If you're paying $0.15/kWh or less for electricity, mining with a very high-end CPU, such as a Phenom 2 X6, is actually marginally profitable at the moment. This even with the recent drop in value and fast rise in difficulty, which implies that it was more-than-marginally profitable a week ago. (This only applies if you already own the CPU, of course.)

"42" (c) ?

What is the subsidy variable you added intended to be?

as long as complexity rise, only guys with cheap electricity stay in business.
half-year ? maybe faster.
ie, guys with access to industrial area, living in Russia or under Nuke power station

Well, it's not exactly a calculator, but maybe this is useful. All the numbers scale nicely: that is, if you want to look at the 1M-10M difficulty range just multiply all the magic numbers by 10, or if you want to look at exchange rates in the 10-100 range just divide them all by 10.

currently the exchange rate is tanking and the difficulty is on track to go up quite a bit.

For those who have difficulty converting units...

MHash/sec * 60 seconds/minute * 60 minutes/hour * 1 THash/1000000 Mhash = THash/hour

All the numerator units except THash cancel, and all the denominator units except hour cancel.

Btw, someone should throw this up on a website to calculate all this stuff. Exchange rate and difficulty could probably be filled in automatically with a couple of calls to BlockExplorer and MtGox.

No that's right (Well your Thash/hour is a little out but its close), your just paying twice the amount per kWh in power than most of the other results in this thread which is forcing your Magic number to be about half the size (give or take).