How to Farm Chia Coin, the New Storage-Based Cryptocurrency

The new Chia cryptocurrency has already started making waves in the storage industry, as we’ve reported back in April. With Chia trading now live, it looks set to become even more interesting in the coming months. The total netspace for Chia has already eclipsed 2 exabytes, and it’s well on its way to double- and probably even triple-digit EiB levels if current trends continue. If you’re looking to join the latest crypto-bandwagon, here’s how to get started farming Chia coin.

First, if you’ve dabbled in other cryptocurrencies before, Chia is a very different beast. Some of the fundamental blockchain concepts aren’t radically different from what’s going before, but Chia coin ditches the Proof of Work algorithm for securing the blockchain and instead implements Proof of Space — technically Proof of Time and Space, but the latter appears to be the more pertinent factor. Rather than mining coins by dedicating large amounts of processing power to the task, Chia simply requires storage plots — but these plots need to be filled with the correct data.

The analogies with real-world farming are intentional. First you need to clear a field (i.e., delete any files on your storage devices that are taking up space), then you plough and seed the field (compute a plot for Chia), and then… well, you wait for the crops to grow, which can take quite a long time when those crops are Chia blocks.

Your chances of solving a Chia coin block are basically equal to your portion of the total network space (netspace). Right now, Chia’s netspace sits at roughly 2.7 EiB (Exbibytes — the binary SI unit, so 1 EiB equals 2^60 bytes, or 1,152,921,504,606,846,976 bytes decimal). That means if you dedicate a complete 10TB (10 trillion bytes) of storage to Chia plots, your odds of winning are 0.00035%, or 0.0000035 if we drop the percentage part. Those might sound like terrible odds — they’re not great — but the catch is that there are approximately 4,608 Chia blocks created every day (a rate of 32 blocks per 10 minutes, or 18.75 seconds per block) and any one of them could match your plot.

Simple math can then give you the average time to win, though Chia calculators make estimating this far easier than doing the math yourself. A completely full 10TB HDD can store 91 standard Chia blocks (101.4 GiB). Yeah, don’t get lazy and forget to convert between tebibytes and terabytes, as SI units definitely matter. Anyway, 91 blocks on a single 10TB HDD should win a block every two months or so — once every 68 days.

Each Chia plot ends up being sort of like a massive, complex Bingo card. There’s lots of math behind it, but that analogy should suffice. Each time a block challenge comes up, the Chia network determines a winner based on various rules. If your plot matches and ‘wins’ the block, you get the block reward (currently 2 XCH, Chia’s coin abbreviation). That block reward is set to decrease every three years, for the first 12 years, after which the block reward will be static ad infinitum. The official FAQ lists the reward rate as 64 XCH per 10 minutes, and it will get cut in half every three years until it’s at 4 XCH per 10 minutes with a block reward of 0.125 XCH.

Of course, luck comes into play. It’s theoretically possible (though highly unlikely) to have just a few plots and win a block solution immediately. It’s also possible to have hundreds of plots and go for a couple of months without a single solution. The law of averages should equalize over time, though. Which means to better your chances, you’ll need more storage storing more Chia plots. Also, just because a plot wins once doesn’t mean it can’t win again, so don’t delete your plots after they win.

This is the standard cryptocurrency arms race that we’ve seen repeated over the past decade with hundreds of popular coins. The big miners — farmers in this case — want more of the total Chia pie, and rush out to buy more hardware and increase their odds of winning. Except, this time it’s not just a matter of buying more SSDs or HDDs. This time farmers need to fill each of those with plots, and based on our testing, that is neither a simple task nor something that can be done quickly.

Hardware Requirements for Chia Coin Farming 

(Image credit: Tom’s Hardware)

With Ethereum, once you have the requisite GPUs in hand, perhaps some of the best mining GPUs, all you have to do is get them running in a PC. Chia requires that whole ploughing and plotting business, and that takes time. How much time? Tentatively, about six or seven hours seems typical per plot, with a very fast Optane 905P SSD, though it’s possible to do multiple plots at once with the right hardware. You could plot directly to hard drive storage, but then it might take twice as long, and the number of concurrent plots you can do drops to basically one.

The best solution is to have a fast SSD — probably an enterprise grade U.2 drive with plenty of capacity — and then use that for the plotting and transfer the finished plots to a large HDD. Chia’s app will let you do that, but it can be a bit finicky, and if something goes wrong like exceeding the temp storage space, the plotting will crash and you’ll lose all that work. Don’t over schedule your plotting, in other words.

Each 101.4 GiB plot officially requires up to 350 GiB of temporary storage, though we’ve managed to do a single plot multiple times on a 260 GiB SSD. Average write speed during the plotting process varies, sometimes it reaches over 100MB/s, other times it can drop closer to zero. When it drops, that usually means more computational work and memory are being used. Plotting also requires 4 GiB of RAM, so again, high capacity memory sticks are par for the course.

Ultimately, for fast SSDs, the main limiting factor will likely be storage capacity. If we use the official 350 GiB temp space requirement, that means a 2TB SSD (1863 TiB) can handle at most five concurrent plots. Our own testing suggests that it can probably do six just fine, maybe even seven, but we’d stick with six to be safe. If you want to do more than that (and you probably will if you’re serious about farming Chia), you’ll need either a higher capacity SSD, or multiple SSDs. Each plot your PC is creating also needs 4GB of memory and two CPU threads, and there appear to be scaling limits.

Based on the requirements, here are two recommended builds — one for faster plotting (more concurrent plots) and one for slower plotting.