Hey Cat, I've recently done (and re-done) a lot of calculations on CPU mining profitability and in my situation determined that it's now only profitable to mine on two of my most energy efficient CPU's. Even then its not much money. Its enough to cover the electricity costs of the base system while my graphics cards are pumping out scrypt coins.

I've ceased CPU mining on not only core 2 duo's but also core 2 quads that do not support AESNI / AVX kind of accelerated instruction sets which are highly beneficial to some CPU coins.

You mean like CGRemote???

NOT MY IMAGE:

If you shift+right click a windows folder and select "Open command prompt here" it sets the current directory in the cmd window that opens automatically to that folder. You do not need to click any exe files etc.

https://i.imgur.com/TCh4u3x.png

Nice, very much what I'd do if I had the space and capital.

The price change over last week has been <10%, relatively stable for a altcoin. You should buy only if you can justify the purchase to yourself; relying on others for your financial decisions is poor form.

if you are using windows, shift+right click the folder containing vanitygen executables. when the window opens already at that directory path, you can then paste (via the square top left of window) a string like:

Agreed, I used to search for 30+ prefixes at a time

1. Run the latest HP client on one of the machines, ensure all CPU threads are used.
2. Go to debug console, type: "getmininginfo"
3. Use this magic:


4. Multiply by 16
5. Look up exchange rate of XPM on any of the sites which list it. http://www.cryptocoincharts.info/#jump-xpm-btc
6. Calculate your obtainable $/day
7. Calculate your costs: electricity - you'll need a wattmeter of some kind.
8. You can now answer your question.

$100k reward? That's only like 1 year of work from 1 post-doc where I live ($80-90 k/pa).

Sort of. Synthetic diamonds are produced in ton per day quantities for industrial applications, but the problem is that they're normally sub-millimeter size. So there is no practical way to combine them into a typical heatsink. It's the same problem with many of the nanomaterials discovered in the last few decades which in theory have amazing thermal conductivities: it's difficult or impossible to make anything sizable and practical for these uses from them.

A common misconception is that gold is better at moving heat than more common metals like copper. Copper's thermal conductivity is about 23% better than gold. And gold is apparently over 450,000% more expensive, so there's that..

Watercooling is great if you want amazing results from overclocking or a dead silent system, but its also expensive (effects ROI) and can be a huge pain in the ass maintain:

- leaks
- more parts means more crap that can fail (fans / pumps)
- corrosion 
- inferior lifeforms taking over your coolant (I'm looking at you, glycol-based coolants)
- harder to physically move systems unless you have expensive leak-free quick-connect fittings or all loop components are in the one case

When you calculate the extra component costs and the value of your time spend messing around with the above, you could argue it would be cheaper and easier to just buy a second unit of mining hardware instead. But then your hardware is just "normal" and doesn't have any wow-factor.

It's a shame that the demand for results from this service is so low. That means its almost entirely unprofitable for anyone with GPU to try and solve for these patterns. In fact, you are just throwing away money.

Currently the best work is: "Searching for pattern: "1Thanks1" Reward: 0.010400 Value: 0.000001 BTC/MkeyHr"

$842 (bitcoinaverage price) * 0.010400 = $8.75 USD

Time to reach 50% probability on a overclocked Radeon 6870: 17.2 days

Power consumption: measured 120w AC:

0.12 kW * 0.30 $/kWh * 24 hours * 17.2 days = $14.86

Or, I could mine dogecoin (presently #1 scrypt coin) for 17.2 days and earn a profit (after electricity taken into account) of $50.40... and get paid with 100% assurance.

Lots of 40mm server fans operate at speeds up to 10600 RPM, maybe more. Most servers have variable fan speeds, though, so probably about 8000 RPM would be a low/moderate speed for normal operation. That's still several times what most quiet 12cm fans operate at. The Lian-Li case I have has 'silent' fans that operate at 1200 RPM. Fan noise is mostly related to the maximum tip speed of the blades:

4 cm 1RU server fan: Circumference 126 mm and 8000 RPM = 38 miles per hour tip speed
12 cm case fan: Circumference 377 mm and 1200 RPM = 17 miles per hour tip speed

Here is two bags of reclaimed Nidec 4cm fans, 9 watts each, and their Sunon equivalents, 28 in total I think. Perhaps I should do something silly with them. I'm not sure I'd reduce the fan speed in a server PSU, but I suppose the worst that will happen is that it'll overheat and perhaps deliver a fatal voltage spike to your expensive mining hardware when a power transistor or cap explodes.

https://i.imgur.com/T8dJg7a.jpg

Unrelated to the post above, I think the Profitability calculator is useful (although the same info can just be obtained from websites) but its location within the interface (under Settings) seems a bit arbitrary and hard to find.

I see somebody is amused by my work..

So my latest procrastination had several design requirements:

- Must ventilate most of its heat to the outside (hot Australian summer at the moment)
- Must not be audible from any part of the apartment (as declared by the minister of Finance and Tribal Warfare.) outside of the spare bedroom
- Must not burn down the place if some shitty PSU cable/connector catches on fire

But first, some history... The existing solution that worked for ~half a year for my CPU miners (Primecoin/Protoshares): I had installed most of the stuff under the home entertainment unit, complete with fan intake and ventilation duct (this was when I was single, can you tell?):

https://i.imgur.com/bhZUclP.jpg


https://i.imgur.com/lGFLb7a.jpg


https://i.imgur.com/zvjFqOy.jpg


At its height, there were 7 computers in there, ~500 watts of heat nicely ventilated outside. Ambient temps are often 30 deg C all day where I live so more heat from mining is not required...

Anyway, certain people found this setup in the living room unacceptable and a new solution that met the criteria above was created...

Mining box!

https://i.imgur.com/5LwchAJ.jpg


Home of the mining box

https://i.imgur.com/YN8jNaV.jpg


Since the first pics, some motherboards had died, other systems were repurposed. As a result, the mining box would house:

1x core 2 quad q6600, dual radeon 7790s
1x core 2 duo E8400, 1x radeon 5750
2x core 2 duo E7500, (CPU only)
16 port gigabit switch

Here is the power infrastructure, networking (including switch) hidden under a plane of glass. On the right are the two E7500's and in the middle is the E8400 and shitty old 5750 card:

https://i.imgur.com/EI7qYt6.jpg


The Q6600 and 2x 7790 placed on top of the glass which sits sort of diagonally:

https://i.imgur.com/5YP4hDO.jpg


As it turned out, it was very hard to cool this thing while keeping it more or less silent. Most of the things in the box were quiet, but most of the AC powered fans I had to ventilate it were too noisy. I finally tore this rotary vane (squirrel cage) fan out of an old portable air conditioner. I added a cord and switches for it. It has three motor winding taps and can run at 85, 155, or 185 watts (@230 volts). Unfortunately all of these were simply too loud. Even at the lowest fan speed it creates reverberations that can be heard from the other side of the apartment. The solution is to run it on the lowest setting, through a step down transformer that outputs @ 130 volts. This limits the total power consumption (and noise) to 28 watts. The clips on the side are to hold on the dust filter. The plastic lid placed on top of the CPU heatsink is to deflect some of the air coming down from the fan, which can make an annoying whistling noise:

https://i.imgur.com/pLjv8CD.jpg


The box is pressurized by the big fan, and hot air flows up through a duct to the window above:

https://i.imgur.com/nB1WvUj.jpg


Making the wooden window frame and getting the duct to stay in it was a huge pain in the ass. I finally settled on a ventilation fascia installed into the wood, which gave a point to secure the duct to. Its held in place with some reusable zipties and screws.

https://i.imgur.com/7GEIj6J.jpg


Unfortunately, as I discovered later on, making the fan silent by running it at lower RPMs reduced the flow rate too much and things were getting too hot. As a result the Auxiliary Air Accelerator(TM) was created for $9. I'll eventually cut out some metal at work that will make this duct connection and entire top of the box much neater.

https://i.imgur.com/RJedYNF.jpg


https://i.imgur.com/B32i1SX.jpg


The final setup as it probably will be left from now on:
*I changed the step-down transformer to a 1000 VA model so all of the motor speeds can be used if needed

https://i.imgur.com/WNOe5xJ.jpg


There is another two 7790's and a watercooled 6870 (display device) on the HTPC, now much lonelier without its CPU mining brethren:

https://i.imgur.com/55WOwDc.jpg


https://i.imgur.com/y9UZa2E.jpg


So numbers? The CPU mining across all of my systems makes about $8 revenue per day. Mining dogecoin across all my GPU makes about $20-22 revenue per day most day. Power cost per day @0.30 AUD/kWh is about $8 to $9. I have some outdated ASIC strapped to the cooling fans of my makeshift NAS pile which get about $0.15/day? ( ):

https://i.imgur.com/3Zdtnyo.jpg


The end... for now...

Toilet paper and cardboard boxes literally right against stacks of potential ignition sources, A++ would ignite again.

147 page thread on why you shouldn't buy from BFL and there are still people here buying from BFL.

Design hardware to do very specific, simple and repetitive mathematical operations. --> Not suitable for anything else. --> People complaining they can't do anything else. --?