Build a Monero CPU Mining Rig: Part 1 We have always wanted to build a CPU Mining Rig but have always focused on video card-based rigs like the one in our GPU Mining Rig build guide. There’s many reasons why, but it mainly boils down to two things: First, you can mine far more cryptocurrencies with a video-card based mining rig (or an ASIC for that matter). Second, and importantly, CPU mining isn’t nearly as profitable. With that said, we did decide to give it a go.
With the price of Monero gaining steam rapidly, we decided to redirect some effort and build a CPU Mining Rig for Monero (XMR). XMR is the symbol for Monero, a cryptocurrency which uses the RandomX algorithm. Mining RandomX is most efficient with a CPU mining rig where the processor does the heavy lifting.
We do talk about why people build CPU mining rigs, especially as they aren’t as profitable as their video card based siblings (or ASICs). That isn’t the reason for this guide, however. This is for those who have already made up their mind and are wanting to do a CPU-miner. We’ve had several inquiries about writing up a how-to, and this is it!
If you just want to get to the components involved, and why we chose what we chose, skip directly to the Monero CPU mining rig hardware section.
What is a CPU mining rig?
A CPU mining rig is a cryptocurrency mining computer which relies on the computer’s CPU as the primary mining component. This probably isn’t all that surprising. What might be surprising is that there are, and have been, several different types of mining rigs including mining rigs that used hard drives to do the work.
Today, however, it’s really down to ASICs, GPUs and CPU mining rigs, with CPU mining rigs being the least common.
What can you mine with a CPU mining rig?
We’re building this mining rig to specifically mine Monero. Monero is mined with the RandomX algorithm which is best tackled by a CPU-based mining rig. Mining Monero is also the most likely reason one would build a CPU mining rig to begin with.
CPU-mineable Algorithms and Cryptocurrencies
The following cryptocurrencies (often called coins) can be mined with a CPU miner like the one we are building in this tutorial:
While you can mine the cryptocurrencies above with the processor-based mining rig in this guide, we haven’t ran the numbers on what kind of return one would get.
Monero Mining Revenue
At current Monero (XMR) rates (right around $400) and difficulty, the revenue (not including the cost of electricity or the mining rig itself) has been between $1.55 and just over $2.00 a day. That is with the miner running full-time mining Monero and doing nothing else. When you consider the price of building this mining rig, you’ll notice that the ROI is quite some time in the future. So, why build this thing anyway?
Why build a Monero CPU mining rig?
Like we mentioned, mining other cryptocurrencies with ASICs or with a GPU is much more profitable. So, why mine Monero? Why even invest in buying the hardware to build the mining computer in the first place?
People have their own reasons for mining Monero, they usually come down to one, a few or all of the reasons below.
- Support the Monero Cryptocurrency and/or Community – Monero was the first truly private cryptocurrency. Many people believe we are losing privacy at that hands of technology, and support Monero or similar projects to encourage innovation concerning privacy.
- Dual-purpose Computing: Build a High-Performance Gaming Rig which can also Mine Monero – An effective Monero CPU mining rig shares a lot in common with a high-end gaming computer (or computer/workstation for that matter). Building a CPU-mining rig with the specifications required to efficiently mine Monero allows participation into the cryptocurrency world and even the ability to offset the cost of the computer.
- Speculative Monero Mining with the Hopes of Future Gains – Occasionally we’ll mine a cryptocurrency that we think has great utility and/or value even when the profitability is low. We never mine any cryptocurrency that can’t be efficiently mined. Like ourselves, others often mine a cryptocurrency with free CPU cycles (part time or full time) with the intent of holding the Monero in the long term, hoping it continues to rise in value.
- To Learn How to Do So – It’s true. People do enjoy simply learning how to do things. This is part of our reason for building this rig, but it’s not the only one. While we have read about CPU mining rigs, we prefer hands-on knowledge.
Okay, with all that said, why are WE building this mining rig? Our reasons actually span all 4 of the reasons we outlined above. We were about to build a computer to use with newer, more intensive flight simulators. When we looked at the specs we noticed that a mid-to-high end computer build shares a lot in common with a Monero mining rig.
Monero CPU mining rig hardware
A Monero CPU mining rig uses the same hardware as a traditional computer or GPU mining rig to mine XMR. The big difference between a CPU mining rig and a video-card based one is which pieces are the most important. The CPU has much higher importance, as does RAM, but not in how you might think. Here’s the what we’re selecting for this build, and why. If you already know about the different components, you can jus skip to the parts list so you can get shopping.
The items listed below with the pictures are the exact items we’ll be using for the Monero Mining Rig build. There are alternatives in the shopping list below them.
CPU, CPU Cooler and Motherboard
In a CPU mining rig, the CPU is critical as is the RAM. The CPU also dictates the motherboard to be used, and because CPUs run hot while mining (especially if overclocked), the CPU cooler has increased. importance, too.
What we’re looking for in a CPU is high performance and multiple threads and cores. You an go with either an AMD or an Intel CPU, and there are plenty of choices. We’ll be choosing a CPU which is a good price-to-performance balance. We’ll forgo the stock cooler for a larger unit. For the motherboard, we want something that can support the CPU and is well constructed, preferably with additional attention paid to cooling.
CPU Mining Rig Processor: AMD Ryzen 9 3700X
CPU Cooler/Heat Sink for our RandomX Miner: be quiet! Dark Rock Pro 4
Monero Mining Rig Motherboard: ASUS ROG Strix X570-E Gaming *
* As far as motherboard goes, we actually started with a GIGABYTE X570 AORUS Master. Ours was unfortunately DOA, and we built everything up on a ASUS ROG Strip X570-E instead. Between the two, the GIGABYTE X570 AORUS Master has far better cooling and in our opinion is a better motherboard. We may try one again in the future, but unfortunately our first go around wasn’t successful. But, there is no reason why this build shouldn’t won’t with it. We just got a bad one.
RAM and CAS Latency (CAS/CL)
For a CPU mining rig, as far as the RAM is concerned, it’s not so much having as much as you can get your hands on as it is getting RAM with the right specifications. First, we’re looking for two sticks of RAM and we want them capable of 3200 Mhz and with a low CAS Latency. CAS latency is usually expressed as CAS or CL. We’re shooting for CL 14.
RAM: G.SKILL TridentZ Series 16GB (2 x 8GB) F4-3200C14D-16GTZKW
The RAM we have chosen has a CAS or CAS Latency of 14. It didn’t break the bank, either (there’s definitely more expensive RAM that met our criteria). If the RAM above is out of stock we have a few options listed below in the parts list.
We highly recommend a CAS Latency of 14 or less. And, it must be in two sticks of 8 GB or more. We went with 2x 8GB RAM. You can go up to two sticks of 16GB for a total of 32GB of RAM (or more) if you like, which you may if you are looking to use the mining rig for other purposes. Do not go less than two sticks of 8GB, however.
A true dedicated CPU mining rig does not require a massive power supply (PSU). It does require enough power to run the miner during constant operation at a high utilization rate. That makes our choice a platinum PSU and we’ll want it only running at 80% of it’s potential max while mining.
Power Supply (PSU): EVGA SuperNOVA 750 P2, 80+ PLATINUM
In our build, we went with a larger PSU because we had one to use. Go with one that is Platinum rated 750 watt or better PSU and you’ll be good to go.
We’ll be going SSD for our storage. You don’t need a ton of storage and can get what you like. Some lean toward fast disk access. While we don’t recommend getting a slow drive you also don’t need the latest and greatest PCIe 4 spec SSD for this build.
SSD: SAMSUNG 970 EVO SSD 500GB – M.2 NVMe *
* We had this SSD and it performs well enough and isn’t expensive. You can go with a cheaper SSD if you like, and even one that is 250GB. Nowadays when buying an SSD we always go 500GB or higher so it will have a useful life beyond mining. You could go for a 3.5″ SSD as opposed to an M.2 form factor which will cut down on cost. We’ll put examples in the CPU mining rig shopping list below.
Operating System (OS)
You can CPU mine on either Windows 10 or on Linux. We’ll be using Ubuntu Linux in this build. It is free and runs great. One thing to be aware of is that there aren’t great utilities to tweak a CPU in Linux. You can, however, tweak the CPU in BIOS. The motherboard we’ll be using will have the ability to boot into different BIOS’ and to easily flash the BIOS even without any other components functioning.
There are also those that say for a Monero mining rig you want Linux over Windows 10. The argument is that Linux gets higher performance when mining the RandomX algorithm that Monero (XMR) uses. While we haven’t verified this, we did want to mention it.
Case for the Monero Mining Rig
On this one, you can do whatever you like. You will want something with good airflow, and there are plenty of options out there. We aren’t gong to cover putting the mining rig into a case as it is pretty straightforward information. It also differs by what type of case you purchase.
For our Monero mining rig tutorial, we’ll just do the whole build open air on a ramshackle test-bench, a perfectly sized piece of cardboard that shipped with the motherboard. When completed we put the whole rig on a cool open-air case we came across, but will likely move it into a Cooler Master case we have that doubles as a real test-bench.
You’ll need these, but likely have them you can borrow temporarily
You will need the items below full-time for a CPU mining rig, so if you can borrow them from another computer. Else, you would need to buy them.
- Keyboard – You’ll want a USB-based keyboard. If you do need to buy one, we used this Anker Bluetooth set (and love it for general use)
- Mouse – A USB-based mouse.
- Monitor – Any monitor that will take an HDMI input will do.
Monero CPU Mining Rig Parts List and Alternatives
- 1x CPU Mining Processor
- 1x CPU Cooler/Heat Sink
- 1x Motherboard Compatible with the CPU
- 1x 16GB (2 x 8GB) 3200 Mhz low CAS/CL DDR4 RAM Kit
- Corsair Vengeance LPX 16GB (2 x 8GB) DDR4 3600 CL 14 or
- Corsair Vengeance RGB PRO 16GB (2 x 8GB) DDR4 3200 Mhz C14 or
- G.SKILL TridentZ NEO Series 32GB (2 x 16GB) DDR4 3200MHz CL 14 (note this is 32GB, not the minimum)
- 1x SSD Drive – Recommended 250GB at a Minimum
- 1x 750 Watt or Higher Platinum-Rated ATX Power Supply
- 1x Case (anything you want that has high air flow and takes an ATX size motherboard)
- 1x 2GB Minimum USB Thumb Drive (any will do, these are USB 3.1 and much higher GB so they have future use)
- 1x PCI-e Video Card (any card you have, if you do not have one and won’t be video card mining buy something inexpensive)
- You can literally use any PCI-e GPU if you need a suggestion, just ask.
If any of the parts above are unavailable, let us know and we can help out with another that will work with this CPU Mining Rig build.
* The GIGABYTE X570 AORUS Master was our preferred motherboard for this build. It has better construction, shielding and heat dissipation than the ASUS motherboard we ended up going with. Unfortunately, our X570 AUORUS Master was DOA which is why we did this build with the motherboard we did.
Next up: Assembly
Once all the parts arrive, the next step is to assemble the Monero Mining Rig components. We’ll have directions posted within a week or so! We’ll be mining XMR’s RandomX algorithm with our CPU miner soon enough!