Let’s skip the usual slow introduction and get right to the topic at hand: how Bitcoin miners can increase revenue. Generally speaking, there are 2 ways for a Bitcoin mining operation to boost their top line:

• Buy new hardware
• Improve the performance of their current hardware

Buying new hardware is the riskier option of the two, as it typically involves a large up-front capital expenditure that will likely take many months or even years to get a positive ROI, subject to Bitcoin’s price performance of course. 

In comparison, getting more from existing hardware is a no-brainer for most miners. What’s less obvious or well-known is that overclocking is not the only way to increase an ASIC’s hashrate. In this article, we’ll explain how autotuning firmware can boost miner revenue and how it’s different from the better-known practice of overclocking.

Customized Antminer S9 photo by MiningCrate.Com

Overclocking = More Hashrate, Less Efficiency (Max W/TH)

Sometime around early 2018, miners began experimenting with overclocking their ASICs to boost revenue. Overclocking simply means that the ASICs consume more power, hash at higher frequencies, and produce more valid proofs of work than at stock settings. For example, an Antminer S9 that typically produces 13.5 TH/s at 1200 W consumption could be overclocked to produce 16 TH/s at 1600 W consumption instead.

With Bitcoin difficulty adjusting upwards consistently as more and more ASICs come online, the revenue produced by a single machine typically decreases substantially over time. 

The hash price ($/TH of hashrate) has consistently dropped over time as difficulty has risen.

Therefore, miners want to get as much out of their machines as possible, as quickly as possible, before their profit margins get squeezed thin by the rising difficulty. And they are willing to make their machines less efficient (i.e. higher W/TH) with overclocking in order to stack more sats in the short term. 

However, the potential firmware improvements do not stop at overclocking.

Autotuning = More Hashrate, More Efficiency (Max TH/W)

Something many people don’t realize about ASICs is that every individual device is unique in terms of the quality of the hashing chips and the overall manufacturing. This is primarily due to the fact that silicon quality is not 100% uniform, so some hashing chips are naturally better performing than others. 

However, mining companies require standardization when they are purchasing hardware, so manufacturers typically make the ASIC specifications much lower than the maximum performance possible in order to better ensure that every machine they deliver will meet miners’ expectations.

On that note, a lesser-known performance upgrade for ASICs that’s similar to overclocking is known as autotuning. Both overclocking and autotuning involve adjusting the frequencies on the hash boards in order to alter the ASIC’s performance. The difference between overclocking and autotuning is in the intelligence and sophistication of those frequency adjustments.

You see, overclocking is a rather brutish adjustment. Simply increase the frequency on the hash boards in order to increase the machine’s hash rate. Autotuning, on the other hand, is far more sophisticated. Rather than increasing the frequencies of entire hash boards, autotuning firmware can calibrate the frequency on a per-chip basis. In other words, the firmware finds an optimal frequency for every individual chip, sending higher frequencies to higher quality chips or lower frequencies to lower quality chips.

The end result from autotuning is a better W/TH efficiency at any power setting the miner chooses. When combined with overclocking, autotuning can enable even higher hashrates or it can maintain the same hashrate increase while bringing power consumption down. 

For example, the same Antminer S9 that typically produces 13.5 TH/s at 1150 W consumption with stock firmware could produce 15.5 TH/s at 1150 W consumption with a per-chip autotuning firmware.

For miners who have very cheap or even free electricity, overclocking + autotuning is the most effective way to maximize the amount of BTC mined.

Users Choose the Power Limit

In bull markets, autotuning and overclocking tends to be the most common combination as miners aim to maximize revenue while they have better profit margins. However, autotuning optimizations are useful across a full spectrum of mining strategies. 

For example, autotuning at low power limits was very useful for miners using Antminer S9s around the time of the last halving when profit margins were squeezed thin. With Braiins OS, miners can set their power limit at 800 or 900 Watts for S9s and achieve an efficiency in the 70-75 W/TH with air cooled machines, as shown with our cost to mine 1 BTC calculator. (Miners can achieve ever better results with immersion cooling.)

The key value proposition of autotuning firmware is that it will optimize ASIC efficiency at any power limit that you specify, lowering your costs for every satoshi of revenue you earn.

The Market for Autotuning Firmwares

Everybody who’s been in mining for a few years understands how quickly the mining industry evolves. While autotuning is still relatively uncommon today, it will likely become a standard practice among miners within 1-2 years. Miners have several 3rd party firmware providers to choose from, which is a huge improvement from just a few years ago when Bitmain was the dominant hardware manufacturer and there were no custom firmwares for Antminers.

In recognizing the value that autotuning can provide — particularly to miners outside of China who have to wait longer and pay higher prices for new-generation mining hardware — we at Braiins have dedicated ourselves to developing a high performance autotuning firmware for mining operations of all sizes.

Braiins OS is competitive with other ASIC optimization firmwares on cost and performance, but unique in other key aspects such as the open-source foundation, GPL compliance, and the solid reputation that we’ve built through over 7 years of experience in Bitcoin mining.