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Browser Bitcoin Miner

bitcoinplus.com

13 pointsdnadolny22 comments

I've just finished a browser-based bitcoin miner, written in Java (as an applet).

I'd love to get some feedback on it.

Once the page loads, hit "Start generating" and it should start mining bitcoin.

This should be called GlobalWarming@Home because it's so inefficient; it's literally 200x slower than a GPU. The generated BTC are probably worth less than the electricity consumed.

Yes, it is slower than GPU mining. I meant this to be more of an introductory easy to use miner to get people interested without having to download anything or configure anything. So it is slower than GPU, but you can generate a usable amount of BTC to play around with

I wonder, what's the math behind the electricity use of an idle CPU vs a CPU at 100%?

Unless your office is paying for the electricity ;)

--edit-- Really? I'm getting downvoted for a valid point?

True.

I've been thinking this over for a while. Right now, the general consensus is that the price of bitcoin will end up being related to the cost of electricity for computing, and in the long run transaction fees will have to go up or down to make that happen.

I think this will change.

When you have negative externalities like this, where people don't pay for electricity (they're renting, or in a condo/apartment building that has electricity included) or even free CPU power, as in an office, then the economics change. The price of bitcoin won't be tied to the price of electricity/CPU power, it will be tied to the cost of running a website like mine that lets people take advantage of free CPU power.

Yes, I think there will be a "base" of miners who basically have zero marginal cost, then a certain number of "suckers" who think that they'll make money even though they won't, and then "serious" miners whose number will vary according to profitability. Ultimately the base + suckers is probably enough to keep Bitcoin working in some form.

Even if they are, it's not worth it. Using my laptop CPU, I can expect to get a payout of about 0.0003 BTC in an hour and half. Using my gpu at home, I get about 1.25BTC/day.

I'm curious, is your computer usable while you're using your GPU for mining? Or do you have a 2nd graphics card dedicated to mining?

I tried out GPU mining but my computer was unusable while it was running.

Someone on the bitcoin forums[1] has a killawatt meter and measured the difference between idle and 100% CPU. We did the math and for his computer, if the cost of electricity is under 14.1 cents per kWh (and you have your computer on anyway), it's profitable to use my CPU miner.

[1] http://forum.bitcoin.org/index.php?topic=8780.msg127782#msg1...

If I log into my account from multiple computers, I take it that it just does the right thing and accumulate work from all running miners?

I also wonder this. Also, say I have a highly trafficked site with a worthless customer base (say a puppy pictures site for 6 year olds) is there a way I can embed your applet into my site and have it generate me bitcoins invisibly to the six year old? I'd much rather do this than spam them with useless adwords.

Edit: I'm aware that this will only generate about half a cent per hour, but you would be surprised how long kids can browse useless pictures.

That came up on the bitcoin forums (http://forum.bitcoin.org/index.php?topic=8780.0). I've got plans for doing something like that - let you embed the miner in your website so your visitors mine bitcoin for you. It's a really cool idea because you get money based on how long people stay on your page, rather than how many pageviews or click-throughs you have. Instead it's based on a more accurate measure of user interest - time spent on the page.

If anyone's interested in that, leave a reply here, or email me at donny@bitcoinplus.com and I'll let you know when it's ready.

Just my opinion, but this feels really scummy. I'd wonder why your site caused my CPU to spike, and probably consciously avoid it from then on.

I get where you're coming from. Here's an interesting thought: consider this as an alternative to advertising.

Which would you rather: a website use your mind by taking your attention to an advertisement, or a website using your CPU?

Advertising, no contest. Annoying, intrusive ads I have no qualms about adblocking, because they will never actually get me to buy a product. Helpful, non-invasive ads and clearly disclosed affiliate links? Feel free, since I'm getting some benefit too. There is no way for me to benefit from you using my cpu (ignoring the actual content in this comparison, obviously).

I'm sure any embeddable bitcoin miner will be added to adblock pretty quickly, so you won't have to worry.

Would it change your mind if you were given a portion of the bitcoins generated while you were on a site that was doing this?

For some people, yes. For me personally, no. I find them interesting, but I'm not investing in them really.

I think the best way to do it would be to ask, and be very clear about what you're doing. Some people would gladly help you, but others may be more wary.

Heres how I would do it: have a Bitcoin Plus (or whatever) widget box clearly visible on the website. Have it tell the user exactly what it is doing, including the current speed. Highlight the fact that it is an alternative to advertisement and that it only uses idle processing time (or if its used together with advertisement, state that its used to help pay for the site). Finally, provide a stop/pause button so that if it really annoys somebody or actually is causing cpu spikes, its easy to turn off.

That's correct, you can log in to as many computers as you want, all with the same account and it will work. You could even run multiple on the same computer and it would work perfectly - but of course it wouldn't make it any faster.

As I understand it, the real Bitcoin mining money is in GPUs, right? Does this work with GPUs (I'm guessing not)?

Yep, GPUs are much faster than CPUs for mining. A top of the line GPU does 600 MHash/sec, on my graphics card it was doing I think 3 or 4 MHash/sec but the computer was unusably slow, and with a CPU miner I get 2 MHash/sec and my computer is perfectly usable. This is targeting the people who are interested in bitcoin (you can still mine a usable amount), but don't want to set up a dedicated mining machine.

Right now it doesn't use the GPU but I've got plans to do it too (it might be able to work with the new OpenCL stuff that's going on)

My GPU stably does 30 Mhash/s (when I underclock it a little bit), or 55 Mhash/s on stock speeds (about 65 is the max I can get overclocking) but then the GPU temperature increases quite quickly and if left for too long I've seen it do one of two things: automatically underclock to 30 Mhash/s or just crash.

Not sure how to best do it in a (non-obtrusive) applet, but would certainly be interesting to get it working!

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