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Friday, April 26, 2013

Bitcoins and Litecoins: How to Build a Mining Rig

Some of you might think the time is past for building Bitcoin miners, and perhaps you're right. With Avalon talking about open sourcing their ASIC and Butterfly Labs shipping "any day now", we could see a flood of hashing power coming online in the next couple of months. Of course, I suspect the time it will take to actually get a wafer made, cut, and distributed -- and then tested, assembled, and more testing -- is more likely to be another six months, unless the original creator lines up everything so that you just have to order one. In that case, it would probably only take three or four months to get your ASIC from China.

As for Butterfly Labs, the jury is still out on whether they're a scam, an unintentional ponzi, or just highly incompetent with a horrible public relations/customer support staff. I actually emailed them to see if they'd be interested in sending me a unit for review; no response to the email so far, which means they're likely completely understaffed, or they're trying not to let any reputable hardware sites do any coverage. The ponzi aspect is pretty easy to get, though: you offer preorders for an "amazing ASIC" that can hash at 60GH/s while drawing 60W. Eventually, that comes out as 25GH/s at 150W, but demand is so high that instead of fulfilling long-standing orders for the 1500GH/s rigs, you start by shipping a few of your lowest performance solutions (5GH/s).

So far, apparently four units have shipped out, one to a blogger, and naturally that results in a ton of new interest. $274 for a 5GH/s Jalepeno? SIGN ME UP! Except, the current wait time is at least two months according to some sources, and more likely it's two or three times that long -- and that's assuming you ever get the hardware. If I could get a firm deadline, like four months, even now I would be willing to fork over the $1100 or so for four of their Jalepenos. That would net me 20GH/s and use a whopping 120W, which is 4X my current hash rate in about 1/30 the power use, or approximately two orders of magnitude better in efficiency! But they're still unproven, so until I have $1000 around that I can afford to lose, I'm going to hold off.

Which brings me back to building a mining rig. Bitcoin mining with GPUs is still quite profitable. For example, a Radeon HD 7950 can run at about 500MH/s without too much effort, and it will draw about 250W for the system. At the current exchange rate of $137 per BTC, that works out to around $110-$125 per month in BTC with a power cost of around $18 per month. So let's just call it earnings of $100 per month, for a $300 graphics card. Right now, difficulty is increasing about 10% every two weeks, so if pricing stays static you'd make $90 on month two, $80 month three, and after four months you've more than paid for the hardware and as long as the difficulty doesn't get above 60 million or so you should still at least break even -- and in the winter months, you can deduct some of the power cost from your heating bill! :-)

Litecoins are a different story, as ASICs aren't available and may never become available. With a 7950 and a bit of tuning, you can readily get 550kHash/s out of a single 7950. At the current price of roughly $3.80, that works out to $155 per month, or $140 in net income. In less than three months, you could more than pay for a Litecoin mining rig, even in today's pseudo-ASIC Bitcoin landscape. And yes, recently I even put together another Litecoin mining rig for just such a purpose.

Here's what I used and recommend, keeping in mind that you ideally want a motherboard that supports as many GPUs as possible. That rules out AMD's Trinity (FM2) platform, as those motherboards only have two x16 slots as best, and given the price and power considerations I decided Intel was a better choice. There are some big Extended ATX board that support four or more x16 slots, but they're expensive at around $300 minimum, so I figured a solid ATX board was best.

3 x Gigabyte HD 7950 GPUs @ $310 each (the triple fans mean less noise)
3 x PCIe x16 extenders @ $5 each (so you can better separate the GPUs for cooling)
1 x ASUS P8Z77-V Motherboard @ 165 (supports 3 x16 slots and has WiFi)
1 x Kingwin Lazer Platinum 1000W PSU @ $180 (room to spare on power)
1 x Intel Celeron G1620 CPU @ $52 (no need for a fancy CPU)
1 x Mushkin 2x8GB DDR3-1600 RAM @ $98 (you could get 2x4GB, but this gives you room to spare)
1 x ADATA 60GB SSD @ $70 (you could get a slightly cheaper HDD, but you don't need a lot of storage and the SSD is faster booting, cooler running, and generally more desirable)

Now, here's the big question: where to store all the components. I can tell you from experience that having everything in a case just makes for hotter quarters, so if you don't mind going ghetto you can grab a plastic crate and store stuff in there. Otherwise, I'd suggest getting a really inexpensive case that you can dismantle a bit, since you want to spread out the GPUs to provide better cooling opportunities -- the Gigabyte case should work. If you want a "real" case, though, I'd get a full ATX tower, and Silverstone has some good options like the TEK SSI-CEB for $100. What about the OS? Well, get yourself a copy of Windows if you must, or get comfortable with Linux for free. I may see about doing a Linux configuration guide for Litecoin in the near future, once I've gotten familiar with the process, so stay tuned.

Grand Total: $1510
Expected Returns: $500 per month

Note that rate of return could go up or down depending on price and difficulty. I expect it should pay for itself within four months at most. There's more good news as well. The GPUs come with a game code good for three free games, which you can sell on eBay for typically $50 or so each. Second, even if Bitcoin and Litecoin become unprofitable for GPU mining at some point, you still have a very nice system -- well, the CPU is weak so you might want to upgrade to a Core i5-3570K or a Core i7-3770K. You should be able to sell such a system for at least $750, even if you only have one GPU in it -- $1000 would be reasonable with two GPUs.

So mine for as long as it's profitable, make a few upgrades, sell the hardware, and you could easily earn $5000 extra this year. That's my plan at least! And I'd seriously consider saving all of your Bitcoins and/or Litecoins for a while -- I could see Bitcoin hitting $1000 in the next few years, so at 2.5BTC per month, decreasing 10% each month, you'd end up with around 25 BTC by that time. Or if you hold LTC, you could have 1200 LTC by the end of a couple years, possibly more. At that point, sell them for $25 each and pay off all of your debt!

If you find this guide useful, I gladly accept donations:
BTC: 1JSrAuxPUhD2rS6yYLiPPT6X8fvz7c7k1W
LTC: LXpEZcNJtikd263z7Ha3vrdYDcLU7hiKWv

Update: Need help? See my Toubeshooting Guide.

Thursday, April 11, 2013

TopPower Nano: When Is Gold Not Gold?

Okay, I admit it: I got duped! I was in the market for a good power supply to run my new Litecoin mining PC, so naturally I went to Newegg and searched for "80 Plus Gold" efficiency power supplies. As the PC currently has two high-end Radeon 7950 GPUs running full tilt (and I might add a third), I also wanted at least a 1000W power supply. A quick search at Newegg gets you these results. The TopPower 1000W is currently out of stock, most likely thanks to other unwitting purchasers like myself.

What really amazes me isn't that someone tried this -- it's that they so far have gotten away with it! Well, that or they changed the packaging? Anyway, check this out: TweakTown calls it an 80 Plus Gold, and so does HardOCP. It looks like the front of the box had an "80 Plus Gold" sticker for both reviews, but look at the back of the box (these are my photos, but the above reviews have the same image, more or less):
Okay, so now it gets interesting, right? The box says 80 Plus Bronze, but that's because the box is sort of made for all of the six PSUs in the same family. The front of the box is clearly different (it says 1000W), but that's just a sticker over the original label (most likely 700W). So the question is: is this an 80 Plus Gold or an 80 Plus Bronze?

To answer that, let's turn to the HardOCP review. Oh, what's that? It fails to reach 80 Plus Gold certification levels? Color me not surprised. They pretty much skewer the TopPower, and rightfully so (good job, [H]. It did better over at TweakTown, where it appears to actually meet the requirements. They gave it an award as well, based on the value proposition. So which is it, Bronze or Gold?

Unfortunately, in my book it's neither -- at least in terms of awards. I've read a few other reviews, and I've come to the conclusion that there's a good reason this is the least expensive 1000W "gold" power supply around: it's also one of the worst. Thankfully, even a bad "80 Plus Gold" is usually good enough, but hopefully I don't end up eating my words. You see, a PSU may not seem like a big deal -- it just supplies power, right? -- but if you end up with a PSU failing at some point, it can take out most of the rest of your PC as well.

If I had it to do over, I'd spend more to get a power supply with better reviews and a real 80 Plus Gold efficiency, like this KingWin. In fact, all things considered at that price I would just go whole hog and upgrade to 80 Plus Platinum, which once again lands me with KingWin, this time with the LZP-1000. The Platinum model even gets a JohnnyGuru Recommended award, which is about as good as you'll find.

In the meantime, my Liteminer PC is chugging along merrily at around 1100kHash/s from the combined GPUs. That should get me around 4-5 LTC per day, which works out to a mere $6.75-$8.50. You see, Litecoin (and Bitcoin) just took a tumble on pricing, to about half their former value. Still, with a power use of around 600W for Liteminer, that's about $1.50 per day in electricity, so $5-$7 in profit isn't terrible. It does mean that it might take a few more months to pay off the hardware in Liteminer, at least if I were selling my LTC.

You see, I did that before with BTC; I could have stocked up on roughly 1000BTC if I had just been patient, and that would have been worth more than my house just last week! It might take a while, but we've been here before and I expect BTC and LTC are both here to stay; now, it's only a matter of waiting for the pricing to get high enough! My current MtGox has a standing sell order in for the crazy eights: $888.88. I wonder how long it will take us to get there? I'm hoping before the end of 2014, as that will take care of all my debts and then some. :-)

BTC: 1JSrAuxPUhD2rS6yYLiPPT6X8fvz7c7k1W
LTC: LXpEZcNJtikd263z7Ha3vrdYDcLU7hiKWv

Thursday, April 4, 2013

Bitcoin Breaks $100, Litecoin Rising As Well

A little known fact is that I started mining Bitcoins back in June of 2011 -- right around the height of the initial Bitcoin bubble. I had some spare hardware handy, read an article, and decided to give it a shot. After mining a couple coins in a couple days and selling them for over $20 each, I did some math and figured as long as the price stayed above $3 or so and difficulty wasn't too high, I could make a bit of extra money with Bitcoin.

My initial set of hardware allowed me to hit roughly 2000 MHash/sec, which was good for over 1 BTC per day. As the price came crashing down, eventually bottoming out at just under $2, many people quit Bitcoin and so with an improved 2500 Mhash/sec and an electricity cost of about $125 per month for the PCs I was mining with, I started seeing as many as 4-5 BTC mined per day. At $2 I was right around the break even point, and other than a week or two I kept mining. Sadly (for me), I kept selling the coins to pay for power and other bills, and I lost 80 BTC with the Bitcoinica disaster.

Last January, I watched the price go from $3 or so back into the $10+ range and suddenly I was clearly making a profit again. Hindsight is always 20/20, but I sure wish I had hoarded a few coins, because in the past two months BTC went from $20 to the current price of $135! Over the nearly two years I've been toying with Bitcoin, I figure I've mined in the neighborhood of 800 coins (primarily with the mining pool, if you're wondering). Had I saved those coins rather than selling, I could have paid off all my debt and half of my house today!

So why this post, and why now? With custom ASICs coming online and the mining reward halving late last year, Bitcoin mining is becoming increasingly questionable on GPUs, and CPUs are totally out of the equation. But there are alternate cryptocurrencies, like Litecoin. Due to differences in the cryptography algorithms backing the currencies, ASICs aren't likely to touch Litecoin for a while, and it was designed to actually be more CPU mining friendly. So, now I've decided that while my high-end Bitcoin mining GPUs will continue in that realm for now, I'm going to see about mining some Litecoins with the lower end GPUs as well as my various CPUs.
What does that get me? At the current difficulty, a single quad-core Intel processor will manage somewhere in the neighborhood of 50 KHash/sec. That may not seem like much, but do a quick run over the and look at the reward estimates. A single CPU mining at 50 KHash/sec will get you nearly 10 LTC per month. With Litecoin now trading at over $4.00, that's $40 per month of potential income, with one of the worst ways of mining for LTC. (Doing Bitcoin, that same CPU would only manage about 15 MHash/sec, with a potential monthly income of around $5.)

Where does all this take me? First, I've started mining LTC now at around 500 KHash/sec, which means potential earnings of $400 or more per month. Second, my Bitcoin mining is now making me around $1100 per month, and currently rising. So, while I might sell a few coins here and there, my plan is to only sell enough to pay for power if needed, and just keep all the LTC and BTC I mine for the foreseeable future.

I thought a year ago that Bitcoin would never reach $20 again, let alone $50 or $100. Now, with the massive increase in public awareness over the past couple of weeks I'm thinking $1000 might not be all that crazy -- and that's a tame estimate compared to the bulls over on forums talking about $10K and more for a single Bitcoin! Meanwhile, I can see Litecoin potentially following a similar path, and even if it remains valued at 1/25 of Bitcoin it's actually currently more profitable to mine LTC with the prices we're seeing.

If you'd like to know more, or if you're a friend who lives nearby and would like to give Litecoin or Bitcoin mining a shot, I'd be happy to build you a potent mining rig. I talked with a friend last night about this and ran some numbers, and I figure $2000 for a system that could mine at around 1500-1600 KHash/sec (or MHash/sec if you do Bitcoin) is entirely possible. I think BTC mining is set to get even more difficult as more people start doing it, plus all the ASICs, so Litecoin looks to be the better long-term proposition. That $2000 PC would end up mining roughly 300LTC in the first month, which would be $1200. In less than two months it would pay for all the high-end hardware inside, at which point everything else is profit! (Bitcoin would be more like $500 per month, and less if/when the difficulty goes up.)

Okay, there's a TON of terms and phrases used above that I didn't bother to explain, but let's end this simply: cryptocurrencies have serious potential to outperform gold and silver, so long as we have the Internet. If you want help setting something up, drop me a note and I'll be happy to provide some input. I'll even accept payment in LTC if you want a "no risk" proposition! My plan is to have well over 1000LTC stored up by the end of the year, and if all goes well at some point down the road I'll have several thousand LTC that are each worth the $135+ Bitcoin is currently valued at.

I missed out on stockpiling BTC because I was too timid, but I'm not going to make the same mistake with LTC! So come join the fun, and if you find this useful then please donate to one of the following addresses:

BTC: 1JSrAuxPUhD2rS6yYLiPPT6X8fvz7c7k1W
LTC: LXpEZcNJtikd263z7Ha3vrdYDcLU7hiKWv