Smarter Clock Speed Management for Bitcoin Miners: Maximize ROI, Minimize Waste

Mining Software

Published

23.5.2025

In today’s dynamic mining environment, maximizing returns requires more than just plugging in the latest machines. From energy markets to firmware limitations, miners must navigate multiple variables to stay profitable. One of the most overlooked levers? Clock speed management, adjusting how hard your machines work depending on market conditions. At Braiins, we believe this is an untapped opportunity. That’s why we’ve introduced Performance Settings in Braiins Manager, bringing native support for managing power modes on stock firmware and precise power target configuration for Braiins OS devices. Let’s explore why this matters and how you can start making smarter decisions on performance tuning.

Table of Contents

Understanding Clock Speed Management

Clock speed management refers to adjusting the operating frequency of mining chips to balance performance and energy consumption. This strategy is crucial for adapting to fluctuating energy prices and varying miner capabilities.

Downclocking (reducing clock speed) typically lowers power consumption and improves efficiency (lower J/TH), but not simply because the frequency is reduced. The real gain in efficiency comes from the fact that voltage can also be lowered alongside frequency. Since power consumption scales with the square of the voltage (W = a × F × V²), even modest voltage reductions can lead to significant energy savings. This makes downclocking especially effective for older-generation machines operating in high electricity-cost environments.‍
Overclocking (increasing clock speed), on the other hand, boosts hashrate but often requires higher voltage to maintain chip stability. Because of the exponential relationship between voltage and power, this leads to worse efficiency (higher J/TH). Overclocking is best suited for newer, highly efficient models in low-cost energy markets, where maximizing output per machine outweighs the hit to energy efficiency.

⚖️ In general, there’s a trade-off: the higher the clock speed, the worse the efficiency, and vice versa. Smart miners use this dynamic to fine-tune operations for current market conditions.

Not All Hashrate Is Created Equal

Bitcoin miners aren’t just power-hungry, they’re also increasingly diverse. From older-generation hardware like the Antminer S19 to newer models like the Antminer S21 Pro, machines differ in their optimal operating ranges. Depending on your electricity rate, it can be more profitable to downclock older machines or overclock newer ones, rather than simply running everything at factory settings.

Clocking Strategy by Hardware Model

Miner Type	Strategy	Rationale
Older Models (e.g., S19j Pro, M30s)	Downclock	Avoid unprofitable hashrate at high energy prices, and unlock profitability for older-generation miners.
Mid-gen Models (e.g., S19 XP, M50s)	Adaptive (case-by-case)	Profitability highly depends on firmware and energy price
Newer Models (e.g., S21 Pro, M60s)	Overclock	Maximize return on investment when power cost is low

Breakeven Efficiency: Why Every Joule Counts

As of today (May 20, 2025), the hashprice is $0.055/TH/day, which means that a miner’s profitability depends heavily on how efficiently it converts energy into hashrate.

1. Miner Efficiencies: Stock Firmware vs. Braiins OS

First, let’s look at the nameplate efficiencies of common ASIC models, and how Braiins OS can improve upon them by operating miners at clock speeds that optimize efficiency. These gains are typically achieved by downclocking, which allows for lower voltage, and since power scales with the square of voltage, this leads to significantly better J/TH performance.

Miner Model	Stock Firmware Efficiency (J/TH)	Braiins OS Efficiency (J/TH) and Relative Improvement
Antminer S9	98	70 \| +29%
Antminer S17	45	31 \| +31%
Antminer S19	34	26 \| +24%
Antminer S19j Pro	30	23.5 \| +20%
Antminer S19 XP	21.5	19.5 \| +9%
Antminer S21	17.5	15.4 \| +13%
Antminer S21 Pro	15	14.1 \| +6%
Antminer S21 XP	13.5	11.9 \| +12%

⚙️ Braiins OS uses its autotuning engine to calibrate voltage and frequency for each hashing chip. The result? Miners operate closer to their physical potential, achieving higher efficiency at chosen performance targets.

2. Breakeven Efficiency vs. Energy Price

Now, let’s match efficiency to electricity prices. The graph below shows how much energy (in Joules per TH) a machine can afford to consume at a given energy price and still be profitable, assuming the current hashprice is $0.055/TH/day.

Now, let’s compare Stock Firmware and Braiins OS to see at which energy prices ($/kWh) it makes sense to operate your miners, given a hashprice of $0.055/TH/day.

Energy Price ($/kWh)	S9	S17	S19	S19j Pro	S19 XP	S21	S21 Pro	S21 XP
0.00	🟢	🟢	🟢	🟢	🟢	🟢	🟢	🟢
0.01	🟢	🟢	🟢	🟢	🟢	🟢	🟢	🟢
0.02	🟢	🟢	🟢	🟢	🟢	🟢	🟢	🟢
0.03	🟣	🟢	🟢	🟢	🟢	🟢	🟢	🟢
0.04	❌	🟢	🟢	🟢	🟢	🟢	🟢	🟢
0.05	❌	🟢	🟢	🟢	🟢	🟢	🟢	🟢
0.06	❌	🟣	🟢	🟢	🟢	🟢	🟢	🟢
0.07	❌	🟣	🟣	🟢	🟢	🟢	🟢	🟢
0.08	❌	❌	🟣	🟣	🟢	🟢	🟢	🟢
0.09	❌	❌	❌	🟣	🟢	🟢	🟢	🟢
0.10	❌	❌	❌	❌	🟢	🟢	🟢	🟢
0.11	❌	❌	❌	❌	❌	🟢	🟢	🟢
0.12	❌	❌	❌	❌	❌	🟢	🟢	🟢
0.13	❌	❌	❌	❌	❌	🟣	🟢	🟢
0.14	❌	❌	❌	❌	❌	🟣	🟢	🟢
0.15	❌	❌	❌	❌	❌	❌	🟢	🟢
0.16	❌	❌	❌	❌	❌	❌	🟣	🟢
0.17	❌	❌	❌	❌	❌	❌	❌	🟢
0.18	❌	❌	❌	❌	❌	❌	❌	🟣
0.19	❌	❌	❌	❌	❌	❌	❌	🟣
0.20	❌	❌	❌	❌	❌	❌	❌	❌

^{Legend: 🟢 Both}^{Braiins OS}^and^{Stock FW}^{profitable, 🟣 Only}^{Braiins OS}^{profitable, ❌ Neither firmware profitable.}

📉 As electricity prices rise, only the most efficient miners remain profitable. This is where Braiins OS creates real economic headroom. Cheap electricity, most efficient hardware and cutting-edge FW are keys to profitable mining.

3. What If Power Prices Spike?

Even with optimal efficiency, there are times when no miner can remain profitable, especially during extreme spikes in electricity prices. This is common in index-priced contracts², where your rate is tied directly to real-time or day-ahead market prices.

That’s where Strike Price Curtailment comes in.

When power prices exceed your profitability threshold, Braiins Manager can automatically pause your miners and bring them back online when the price normalizes. You define your strike price per miner model and Braiins Manager handles the rest.

🛡️ Think of it as a safety net against price spikes that would otherwise burn through your margins.

👉 Learn more about Strike Price Curtailment in our dedicated article.

Braiins OS: Intelligent Efficiency with Autotuning

When operating with Braiins OS, miners gain more than just additional control, they gain intelligence.

Whenever you set a new power target or hashrate target on Braiins OS, the system uses a proprietary autotuning algorithm to calibrate voltage and frequency settings for each hashing chip. This chip-level calibration ensures that the machine reaches optimal performance and efficiency (J/TH) for the selected target.

This autotuning process is the most advanced in the industry and ensures that your hardware operates in the most cost-effective way possible, without requiring manual adjustments or trial-and-error. Just set your preferred power or hashrate target and let Braiins OS to do its job, to set frequency and voltage for each chip in a way to mine on the edge of the particular miner.

Stock FW vs. Braiins OS: What’s the Difference?

While stock firmware provides some level of performance control through preset power modes (usually just 1 additional setting: low or high clock speed), it lacks the granularity and flexibility needed for optimal efficiency across changing market conditions.

Braiins OS offers:

Fine-grained power and hashrate target settings
Advanced chip-level calibration via autotuning
Support for Dynamic Power Scaling (DPS) for automatic reaction on heating conditions of the miner
Full batch configuration capabilities via API or GUI

Feature	Stock Firmware	Braiins OS
Power Mode Presets	✅	❌
Custom Power Targets	❌	✅
Custom Hashrate Targets	❌	✅
Dynamic Performance Scaling (DPS)	❌	✅
Batch Configuration	Limited	Full Support

Performance Settings in Braiins Manager: Your Control Center

Braiins Manager now gives you centralized control over performance settings, letting you adjust how your miners behave based on your strategy and the market conditions.

With just a few clicks, you can:

✅ Set power modes on miners running stock firmware across major brands:
- Antminers
- Whatsminers
- Avalons
✅ Define power targets on Antminers running Braiins OS, unlocking more precise control over power consumption and efficiency.
✅ Apply changes in batch across hundreds or thousands of miners with an intuitive, guided UI. Whether you’re overclocking to ride a low-cost power window or downclocking older units to avoid losses, Manager makes it fast and frictionless.

Final Thoughts

Smart miners are moving beyond “set-and-forget”. With power prices fluctuating and miner performance ranges widening, dynamic clock speed management is no longer optional, it’s essential.

By combining Braiins OS’s granular control with Braiins Manager’s centralized configuration, you gain the tools to optimize your operation minute-by-minute, not just machine-by-machine.

Ready to take control?

👉 Install Braiins OS on your miners

👉 Try Performance Settings in Braiins Manager

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¹ Best measured efficiency on Braiins OS at the power target where we saw the best result.

²Electricity supply agreements where the price you pay is directly tied to a market index, such as real-time or day-ahead prices in wholesale power markets. This means your energy cost fluctuates based on supply and demand, often leading to very low prices during off-peak hours but potentially extreme spikes during peak demand or grid stress.