2. HARDWARE & EQUIPMENT
2.1 Open Air frame
2.2 GPUs & PSUs
2.3 Motherboard and perifpherals
2.4 Cable Management
2.6 Environmental protection and cooling
2.1 Open Air Frame Other then your GPUs, your frame may be the most important thing your purchase and design. Temperature control, cooling, scaling, repairs, and upgrades are all heavily reliant on a well assembled well designed open air frame.
While your rig doesnt need to be pretty or a Picasso-like work of art it does need to be functional and allow for cooling, growth and maintenance. The best open air designs seperate components out, allow for proper air space, and are designed in a way that you can easily get to all component in the event in which they nee to be swapped our or repaired. There are a few considerations here and while there are dozens of great designs I will be presenting one in which I believe covers all the bases,
You’ll want to choose a good material:
-Something that conducts heat well
-Something that is light and can be easily moved
-Something that is cost effective
-Something that isn’t prone to produce dust or particles
Lightweight metals such as aluminum are a great choice. Aluminum tubing and aluminum angle are lightweight, cost effective, available at most hardware stores, and dont produce dust or particles that may get sucked into a fan intake. While aluminum angle is easily assembled, I prefer the modularity of aluminum tubing with connectors.
http://www.estoconnectors.com/ is a great online source for aluminum tubing and connectors. the snap in connectors make it easy for anyone to quickly assemble a sturdy box-type frame. The materials can but cut to custom sizes and is fairly inexpensive. I built a 24 X 18" custom cut 2 tier frame for less then $65 including shipment.
A good open air rig is more then just the box frame. You will want to have 2 tiers. An upper tear for your graphics cards and a lower tear for your motherboard, peripherals and power supply.
The bottom shelf should be sturdy and be braced. this will reduce vibrations which can lead to wear and tear or damage over time. As you can see from the photo above we attached 3 pieces of 1/4" thick aluminum across the bottom of the box frame to help brace the shelf.
For the shelf you want to use something sturdy. We chose a 1/8" piece of stainless steel sheeting. This has the weight to remain sturdy and reduce vibration from the equipment running on it. Since this is our first rig there was no consideration for air flow on the bottom shelf. however if this was a second rig, we would instead use a perforated steel sheet for airflow for the GPUs stacked on the rig below.
You will also want to stabilze your components. Drilling motherboard standoffs into the steel base will allow to attach your motherboard and provide airspace for it so it doesnt come in contact with the steel which could cause a short.
You can also use the Aluminum angle to create a bracket to hold your PSUs in place.
The Top Shelf should have a ledge or flange for the GPU to screw into as well as a rear crossbar to support the back of the video card and hold it into place. To achieve this you can attach a piece of Aluminum angle across the frame
For a full list of framing materials, lengths, and a how-to on assembling the frame please send me a private message or check out my Open Air Frame Assembly Guide [Link to Come] Here is what the finished product looks like:
2.2 GPUs & PSUs GPUs and PSUs are the most important hardware components of your mining rig. for GPUs there are several considerations. We already covered “what to mine” in section one and will now focus on which GPUs are the most reliable and profitable for current and future mining.
There are 3 major considerations:
-The initial investment (Cost of the GPU)
-The Hashrate vs Power consumption Ratio
-The long term mining ability.
Initial Investment How quickly you reach your ROI is directly proportionate to how much you spend for GPUs. While GPUs are still somewhat tough to source at cost/without a market things have settled down to where you can find most cards retailers or through online stores. While one GPU may drastically outperform another, it may make sense cost wise to go with another GPU. for example if you are able to buy TWO GPUs with a 18 MH/s output for $20 each that may be a better option then buying one card with a 35 MH/s rate for $500. So keep initial cost of hardware in mind when making this decision. This will vary quite a bit depending on where you live and what options are available to you at the time.
Hashrate vs Power consumption Ratio
There are a few different philosophies on Hash vs. Power Consumption which are influenced not just by opinion but by area. If your power costs are low (or free) Hashrate become most attractive. Additionally with difficulty going up over time, hashing as many coins as possible in the early stages is also a consideration. if you live somewhere with high power costs, power consumption becomes critical. For this guide we will assume all things are equal.
Below is a chart of viable GPUs from a Hash vs. Power perspective sorted by hashrate (no necessarily by best ratio)
AMD Radeon R9 295X2 - 46 MH/s @ 325 W
AMD Radeon RX VEGA 64 - 40 MH/s @ 165W
NVIDIA GTX 1080 Ti - 32 MH/s @ 125W
NVIDIA GTX 1070 - 27 MH/s @ 105W
AMD RX 580- 22 MH/s @ 75W
AMD RX 480 - 20 MH/s @75W
*** Disclaimer. These rates are subject to change and may vary based on driver and bios configurations. There are tons of resources on hashrates. Please do your own research and check the mining forum for real life results people are getting. ***
I’ve personally tested both the GTX 1070 and AMD RX VEGA. I find these to be the most measurable, cost effective GPUs that provide high hash rates with reasonable power consumption. Please check out my AMD RX VEGA mining rig breakdown here:
The RX Vega and GTX 1070/1080 are both great long term mining options. There may be better alternatives or better options based on your situation (Budget,environment, power costs). Please do your research or consult the forum to help make this decision.
Long term mining ability. Just because a GPU mines well now does not mean it will continue to mine well in the future. There are 2 major considerations when considering long term mining ability. Difficulty and Dag.
Over time as coins are mined the difficulty of the algorithms increase. This is a sort of check and balance put in place on the block chain to ensure the security of the ledger and that no single entity can manipulate the blockchain. For more on this, read the bitcoin white paper or read up on how proof of work functions.
The important thing to keep in mind however, is that the difficulty WILL increase. So you will want as much hash power as you can get. whether that is achieved with scale (many GPUs) or Raw power (GPU hash rate) you want to try and squeeze as much hashrate as you can out of your rig while remaining profitable in respect to power consumption.
The second, and more important consideration is the DAG (Directed Acyclical Graph). The DAG basically maps out the algorithms and instructions. It must be loaded into memory almost like a header. Why is this important? Because the DAG grows at each increment. These increments are called “Epoch” and come in 100 hour increments. At a certain point, a GPU will not be able to fit the DAG into memory… this takes quite some time, however in the near future (at approximately epoch 199 or 200) cards with only 4 GB of GDDR5 RAM will no longer be able to handle the DAG and will not be able to mine Ethereum. Additionally, as we approach Epoch 200, the DAG will consume more and more of that 4 GB of RAM cutting into the hashpower of 4 GB GDDR5 RAM GPUs.
What does all of this mean? In Short: Make sure your GPUs have 8 GB or more of memory.
One consideration of going with the AM RX VEGA was its 8 GB of HBM2 memory. RX 480/580 card models with 4 GB of memory are now flooding the secondary market. if you plan to mine, stay away from those 4 GB models.
PSUs are the other important hardware component. This is not only going to power your rig and keep it online, but also factor into your energy costs. All PSUs are not created equal. Some are much more energy efficient then others. It is also important to understand how much power your need. There are 3 major considerations when choosing a PSU:
If your Rig is going to draw 1000W you dont want a 1000W power supply, you want more juice then that as PSUs are not designed to run on their maximum load 24/7. You can refer to this site to help calculate your power consumption and how big of a PSU you will need:
It is also important to not run all your GPUs in series. You dont want to be running several GPUs on the same PCIE or SATA cable. I like to have once dedicated for every GPU or no more then 2 GPUs on one cable. Please refer to the forum and this Thread on GPU mining electrical needs:
PSUs are typically rated into 4 categories: Bronze, Silver, Gold, and Platinum. Bronze being the least efficient and Platinum being the most efficient. Why is this important? Because the more power you waste/use the less profitable your mining rig will be.
PSUs convert AC current from the wall and convert it to DC power for your rig. during this conversion there will some power loss. This also produces more heat. The higher efficiency power supplies require less AC current to produce the same amount of DC power and produce less heat. (which is also important as many GPUs hash better at lower temperatures). You can Save 5%, 10%, or even 20% on energy costs with a Gold or Platinum PSU.
The last factor is cost. PSUs, especially the gold rated ones, can cost up to $200 or more. The more you spend on a PSU, the more profit you need to make to reach your ROI. And as mentioned in the Redundancy/Single point of failure portion of Section 1 above, you are going to want to have multiple PSUs in your mining rig. So choosing the most cost effective PSU and balancing that vs. the most efficient PSU is an important calculation.
Pro-Tip! Instead of purchasing an expensive high end gaming PSU, purchase an old server PSU. Server PSUs are built to run 24/7, are platinum rated, and are very inexpensive ($15-$35). You can purchase a Pair of 1000-1200W PSUs to power your GPUs and a 225W PSU to power your motherboard all for under $100.
ServerSupply.com sells HP proliant PSUs here:
Important! you will also need a breakout board. Server PSUs attach modularly to server motherboards. In order to get 6 pin PCIE interfaces you will need a breakout board. The X6 breakout board is available on both ebay an parallel miner:
2.3 Motherboard and peripherals Purchasing the right motherboard is very important and it is easy to mistakenly buy something that appears to meet the needs of your mining rig but falls short. For example, a 6 card mining rig will require 6 PCIE slots in order to run all 6 cards. There are plenty of motherboard that come with 6 or more PCIE slots. The problem is a lot of these motherboard are not made to handle 6 GPUs running simultaneously and while they can run 6 PCIE devices at the time they weren’t designed with GPU mining in mind. They were designed to handle a couple of graphics cards in addition to other PCIE devices such as RAID controllers, NIC adapters, Card readers and other PCIE interfaced hardware.
Luckily, with the expansion of GPU mining, hardware manufactures have started making motherboards specifically geared towards GPU mininig, ASRock, BioStar and others make several boards designed to handle 6+ GPUs, and even have “BTC” in the model name.
ASRock H110 Pro BTC+ Motherboard
BioStar TB250 BTC Motherboard
While you don’t need a motherboard marketed as a “BTC” or “Minining” motherboard to run your rig you should do extensive research on whether or not the motherboard you choose can handle the GPUs and has shown to be stable running multiple GPUs 24/7.
Resource: The following is a list of some of the more popular mining motherboards:
As mentioned in section 1 with regards to redundancy and uptime; I would suggest against motherboards with 10+ PCIE slots to run that many GPUs all on one board. Not because the board can not handle it, but because if you do have a motherboard failure you bring your entire operation to a halt.
Now that you have all the main components of your rig mapped out, its time to look into the peripherals, bells, and whistles you will need to connect all the components and optimize your design. At a minimum you will need:
PCIE Risers are extension cables that connect your GPUs to your motherboards PCIE slots. Remember the reason we are building this open air rig is for cooling and airflow so housing your GPUs right in the motherboard would not allow for that cooling and likely overheat your rig. The risers allow you to secure the GPUs on the upper shelf, where air can flow more freely.
There are alot of PCIE risers on the market and most of them are made cheaply and are the component most prone to failure in your rig. It is recommended that your purchase a few spare risers so you minimize downtime in the event of failure.
PCIE risers come in both powered and non-powered versions. It is recommended to use the powered versions over the non-powered 16 pin ribbon cables. The powered versions require less power from your motherboard and from a durability perspective are going to keep you up and running longer. The powered versions are also required for many rigs as most multi PCIE slot motherboards dont have full 16 pin PCIE slots for of their interfaces.
PCIE/Molex/Sata cables Most PSUs and GPUs will come with cables and connectors. But you may not have enough cables to connect all your GPUs or more important connect them all with individual cables. (Running more then 2 GPUs in series is not recommended and likely to cause issues down the road).
If you go with the above recommended route of using HP server PSUs with breakout boards, you wont have any cables included and will need to purchase several 6 pin to 6+2/8 pin cables/connectors. Overall you will want to do a review of all the cable and interface/adapter needs for your components and make sure you have all the required cables. You will also want a few spares for troubleshooting or replacement and most importantly be sure to get the correct lengths so that your cables reach your hardware and arent being stretched.
Hard drives/Storage GPU mining rigs require minimal storage. You will need a drive to run your operating system and GPU hardware. Windows 10 requires 16 GB of drive space for its installation. with software and formatting you can easily get away with a 64 GB hard drive for a windows OS based mining rig. Linux based rigs can run on even less or even run off a usb stick.
64 GB 2.5" or mini PCIE hard drives can be purchased for as little as $35. As mentioned in section one, buying a second drive and cloning your rig after initial tested stable setup or having a backed up .ISO image ready to go for recovery is strongly recommended.
RAM/Memory While GPU RAM/Memory is crucial to the performance of your mining rig, system RAM/Memory is not critical at all. a 4 GB stick of RAM will be enough to power your rig without any issues. With the cost of RAM being so inexpensive, and for redundancy reasons, it is recommended to buy two 4 GB sticks of RAM, keeping your rig operational should one stick fail. a 2 x 4 GB RAM kit will run you as low as $30.
Processor Like system RAM, mining rigs do not require A lot of processing power from the CPU to operate. In fact, it is more profitable not to run a powerful CPU as it wont increase mining performance but will increase your power costs. Using a Pentium or Celeron processor is going to provide all the processing required while consuming less power then an i3/i5/i7 processor and also save you quite a bit of money in hardware costs. Be sure to keep this in mind when choosing your motherboard to ensure the socket can handle the processor you choose.
2.4 Cable Management
Cable management should be considering for any mining operation, especially larger multi rig operation are those expected to scale overtime. Beyond just satisfying those of us who are OCD when it comes to organization, proper cable management while allow you to more easily access components or swap hardware in and out more efficiently. As we have covered several times already, you are losing money every moment your rig is down. to e able to quickly swap hardware and cabling in and out is an important design consideration.
Some best practices for cable management include:
-Use cables of appropriate length, with enough slack to prevent pulling but not so much that it will coil up and tangle.
-Use velcro in place of tie wraps whenever possible. Velcro allows for easy removal and recabling where ties need to be cut.
-when cutting the excess of a tie wrap, be sure to cut right at the knuckle to avoid sharp edges that could cut wiring
-use your frame to secure and space your cables out evenly and channel them to the appropriate areas.
-Avoid crossing cables across the rig, and design your rig so that components connected with cables are closest to eachother.
A UPS (uninterrupted Power Supply) is strong recommended for all mining rigs. A UPS will NOT keep your mining rig running through a power outage… what it will do is allow you to gracefully and safely shut down all the components of your mining rig so that a power outage and sudden shutdown will not damage any of the components.
Protecting your investment is critical. You dont want to be caught setting up an RMA or warranty claim on a GPU that failed during a power outage nor do you want your rig down while you wait 7-10 business days for a new one to arrive. A 1500W power supply can be purchased for as low as $65. Most UPS also have the ability to set up email or text alerts that will notify you of an outage which is a nice feature to have.
2.6 Environmental protection and cooling
Once you have your rig set up and running it is important to protect your rig against its surroundings. Depending on where you store your rig, you may need to worry about things such as dust, debris, moisture,and other elements. Some considerations and failsafes to consider are:
-to keep your rig in a cool, dry area.
-keep your rig elevated off the ground in the even of a spill or flood.whether on a shelf or even building your frame out with legs to elevate the shelves.
-To protect against dust and debris you can line the frame of your rig screen door screen which will allow air flow while cutting out dust and particles. Covering fan intakes with pantyhose is an old IT hack that many people still employ that also keeps dust and particles out.
-Use compressed air to blow any dust or debris out of your rig on a periodic basis.
In addition to keeping your rig dry and clear of debris, proper cooling is also important especially in larger scale multi rig mining operations. While the subject of cooling is vast and beyond the scope of this guide it is important to know that keeping your rig cool is critical not only to keep it from overheating or causing damage but a lot of high end GPUs will also have increased hash rates at lower temperatures.
Channeling heat away from your rig with duct or tubing, fans, or vents can make a considerable difference in how cool your rig will run. While air conditioning is a very effect way to keep your rig cool, be sure to consider the power costs of running air conditioning 24/7, as this may cut into your overall profits or even put you at a loss depending on the power consumption of the air conditioning and electrical costs in your area.