 Okay, based on the response to part one of this series, we could have done a lot better with our first GPU mining computer. But, believe it or not, we knew that... Theoretically, 1080Ti's are the most profitable, but we have to ignore cost to buy. And so today is all about rectifying. Our stupidity, that is. In part two of this series, which is now, we're going to show you guys how you can mine cryptocurrency at home properly. And we're going to build what we call the ultimate 13 GPU price to performance mining rig. Kind of started out with that and then it went away. And we're going to do that after we tell you about today's sponsor. Mack Weldon believes in smart design, premium fabrics, and simple shopping. Use offer code Tech Tips and get 20% off on your next order at the link below. Parts selection might not be thrilling, but it's the single most crucial part of building a mining rig. Now, we touched on this a little bit in our last video, but one of the key factors in a well-designed miner is what's called the ROI time. That is how long it will take the hardware to pay for itself and start generating a profit. Now, our first machine would have taken what? Five years. But a well-designed miner should take closer to four to six months. Now, let's introduce the big star of this video, the motherboard. Most people will just jump on whatever is the cheapest five to seven slot board available at the time. But Asus B250 mining expert, if you can find it in stock, lets us spend a little bit more on the board. And the reason that we can afford this is that we can save on system components that don't affect mining speed like CPUs, RAM and SSDs. Because even if we don't fill it up with the P106 or P104 mining cards that are apparently required for it to reach its full 19 GPU potential, 13 graphics cards is still about twice as many as a normal board. Now, for our CPU choice, this is going to be a little different from normal Linus Tech Tips. We're looking for cheap, cheap, cheap. So Coffee Lake is out of the question. What Jake's installing here is a last-gen Kaby Lake where we'll find some better options like the Intel Celeron G3930, which for around 35 bucks US with the heatsink included is basically steel. Now, as for RAM right now, similar to the CPU, basically we'd recommend whatever is the cheapest compatible memory that you can find from a reputable brand. At the time of filming, this ended up being some bare bones 2400 megahertz DDR4 from Crucial for just under 50 bucks. OK, now we're getting into the tough stuff. It's no longer as simple as just buy the cheapest one you can find. Picking the absolute best GPU for mining would pretty much require a crystal ball, but that doesn't mean we can't make some educated guesses. So for users who are more limited by space, making the most of every PCIe slot by filling their rigs with 1080 Ti's for maximum raw power might make sense. But based on the numbers today, the ROI time for that approach compared to our choice is much longer. So right now, one of the best AMD cards and reliability is a factor here too, is the RX 570 4G after flashing a mining friendly BIOS. And yes, we know Vega is insane at Monero mining, but it has some other issues. So the water-cooled Vega 64 in our mining test server would regularly switch HBCC off for no apparent reason, cutting the hash rate of the card to about the same as a BIOS flashed RX 580. So it's not worth it to us for the extra cost and hassle at this time, even if we could find any of them in stock. Now on the Nvidia side of things, GTX 1060s and 1070s yield similar ROI time to each other, but most miners these days are opting for the 1060 due to its lower upfront costs and better relative resale value. Now, they have their issues. Nvidia cards with suboptimal RAM, yes, graphics cards can use memory from different manufacturers and you cannot predict what you'll get in the box, drop a lot more performance than AMD cards with bad RAM do. But one nice thing about Nvidia cards is that they don't need a BIOS flash in order to hash at their peak. So then we ended up with a balanced approach here. Eight RX 570s, which is a total lie because actually one of them is a 470, three of them are actually 580s. Check out these 580s from Betty Seuss sent over. These things are ridiculous. Thanks, bros. And then we've got two of what are some pretty special passively cooled P104 mining cards that are the equivalent to a gaming GTX 1070. Let's talk about mining cards. Basically, a mining card is a less expensive version of its gaming cousin that comes with beefier power delivery and in some cases claims of better efficiency, which believe it or not, we were able to observe with these sample cards from Manly. So all of that is good stuff. The problem, though, is that they have much shorter warranties and they have no display outputs, which can potentially have a negative impact on their resale value if that's part of your model for making back your money. Okay, so it's assembly time. These mining cards actually just go in with zip ties here because they don't have PCI brackets. So it's just a little, you know, something like that. But that is far from our biggest potential problem now. Actually, yeah, thank you. You guys might have noticed before that the B250 mining expert has PCI Express 1X slots all over the place. Definitely way too small to fit a full sized graphics card. So what gives then? Well, it's designed around the use of risers. So these five to ten dollar kits come with a 16X slot on a little PCB. They come with a power adapter and they come with a USB cable that plugs into, see that? Another little PCB that goes right into, check this out, goes right into our 1X slot, a little something like that. Now, there are a ton of models of these things on the market, but the go-to currently is the VER006C or version 6C. And this was recommended to us by long time cryptocurrency expert Marshall Long. That's OGBTC on Twitter. Now, one tip when powering these guys is to use as few adapters as possible when plugging them in. So ours are run off SATA. So we're going to be using two of these adapters per SATA harness coming out of our power supply. On the subject of power, this is one of the biggest concerns for any miner. And choosing the right power supplies, yes, plural potentially, for your system can be tricky. Now, for small scale miners, changes in efficiency like going from an 80 plus gold power supply to an 80 plus titanium model probably won't significantly impact your ROI time. So most folks go for a relatively inexpensive 800 to 1200 watt unit from a trusted brand, leaving some headroom for more cards if they plan on expanding. Now, one of the best options for a rig like ours would actually be an adapted server power supply that runs 200 volts or more from a company like Parallel Miner. But using one of these relies on having 200 volt power, which isn't common in North America, and relies on finding anything in stock, which was an issue. So we opted instead for three 850-ish watt units. On most boards, you would actually need a jumper like this one to run multiple power supplies. But it's pretty cool. Asus actually thought of that, and the B250 mining expert has three ATX connectors. Next order of business then is finding a place to put all this stuff. So Jakku over here, being the DIY type, he's actually whipped up a couple of different styles of frames to show you guys. And we're going to include the dimensions in the video description if you're interested. This first one was made out of recycled 2x4s that he found at work, and some drywall screws that he found at work on the floor. So it has the advantage of being really, really cheap. But it should be noted that we do not recommend having wood anywhere near a hot mining machine. And we think the additional cost of this metal frame made from 1x1 angled aluminum from the local hardware store is worth the better space efficiency and the lower weight. Though, again, you would want to improvise a non-wooden support system for your graphics cards. For the 13 GPU rig though, rather than building a gigantic chassis, we opted to demo another popular mounting strategy, which is building your miner right into a shelving unit. Now, this isn't great if you have to move it around, but it is pretty darn cost effective because even if you are using racks, you're going to want shelves to put them on anyhow. Okay, so everything's together. We've booted up Windows, we've flashed a few of our GPUs with some customized BIOSes, and we have some mining software ready to go. So we're currently using a management utility called Awesome Miner. And without going into too much detail, that's probably a subject for another video. It basically allows you to control up to 5,000 machines in a single instance, and it can auto-profit switch, notify you if your rigs are having issues, help organize your miners into groups, and a lot more. So with it all set up, we're mining Monero with the CastXMR miner on the AMD GPUs, and then Zcash with the DSTN miner on the two Nvidia cards. And without much tuning, the AMD cards are running an average of 7.3Khz in Kryptonite, and the Nvidia cards are at around 1Khz in Equihash. This all equates to a current average of about 900 US dollars per month in revenue before we pay for power. So at about 10 US cents per kilowatt hour, this config with current profitability is sitting pretty at about a five-month ROI time. That's about 8% of our original rig's estimated ROI time, which is pretty damn good. So guys, stay tuned then for part three of Mining Adventure, where we look at the pros and cons of ASIC miners, because GPUs are not the only way to tackle this. Speaking of tackling things, FreshBooks is the way that freelancers and small business owners can tackle their accounting problems. It's the simple way to be more productive, more organized, and get paid faster. Create and send professional-looking invoices in less than 30 seconds, set up online payments with just a couple of clicks and get paid up to four days faster, see when your client has seen your invoice to put an end to the guessing games, and take the whole experience with you on the go with their iOS and Android apps. For an unrestricted 30-day free trial, just go to freshbooks.com slash tech tips and enter Linus Tech Tips in the How You Heard About Us section. So thanks for watching, guys. If this video sucked, you know what to do, but it was awesome. Get subscribed, hit that like button, or check out the link to where to buy the stuff we featured in the video description. Also linked down there is our merch store, which has cool shirts like this one, and our community forum, which you should totally join.