Bitaxe Efficiency Explained: What J/TH Means for Solo Miners

Bitaxe Efficiency Explained: What J/TH Means for Solo Miners

Spend a little time in home-mining chats and you will see people compare miners with a number followed by "J/TH". It sounds technical, and it often gets thrown around without context — one person quoting a spec sheet, another quoting a screenshot, a third quoting a wall meter. The idea behind it is simple, though, and once you know how to work it out for your own Bitaxe it becomes the most useful single number on your desk.

J/TH — joules per terahash — measures how much energy a miner uses for each unit of work. You get it by dividing power in watts by hashrate in terahashes per second: J/TH = watts ÷ TH/s. Lower is more efficient. To find your own figure, measure wall watts with a plug-in power meter after warm-up, read your average hashrate from AxeOS or the Bitmern Solo dashboard, convert GH/s to TH/s by dividing by 1000, then divide. Some firmware versions display an efficiency figure, but it is based on the board's reported power, which does not include power-supply losses at the wall. Solo finds are lottery-style; efficiency is the part you control. Keep BTC easy-start host btc.bitmernsolo.com with port :3132 (never treat :3102 as the Bitaxe / home default), username WALLET.worker, password x. Current Effort is not a find guarantee.

This is the "efficiency" lane. Monthly running cost has its own formula — Bitaxe power cost. If your dashboard hashrate looks lower than AxeOS, start with expected hashrate vs dashboard. Model differences are covered in Ultra vs Supra vs Gamma.

Bitmern Solo is solo infrastructure: flat 1% fee on finds only, you keep 99%. Nothing in this post is financial advice, and nothing here claims a profit or a find.

Hashrate units first: GH/s vs TH/s

Before efficiency makes sense, the units need to line up. Hashrate is the number of hash attempts per second:

1. H/s — hashes per second.
2. GH/s — gigahashes per second: one billion hashes per second.
3. TH/s — terahashes per second: one thousand GH/s.
4. PH/s and EH/s — larger units used for pools and the whole network.

Home miners often see their own hashrate shown in GH/s, while efficiency is usually quoted per TH. To convert:

TH/s = GH/s ÷ 1000

Getting this conversion wrong by a factor of a thousand is the most common efficiency mistake. If your result looks absurd, check the units first.

What J/TH actually means

A watt is one joule of energy per second. A terahash per second is one trillion hashes per second. Divide one by the other and the "per second" cancels out:

J/TH = watts ÷ TH/s

So J/TH answers a plain question: how many joules of energy does this miner spend to compute one terahash? Lower is better — less energy for the same work.

Two miners can have very different hashrates and still be compared fairly by J/TH. A bigger machine can hash faster but use more power; a smaller one can hash slower but use less. Efficiency puts them on the same scale.

This post does not state a hashrate, wattage, or efficiency for any specific Bitaxe model. Boards, chips, firmware builds, frequency and voltage settings, cooling, and power supplies all differ. Your figure comes from your meter and your dashboard.

A worked example (EXAMPLE values only)

The numbers below are placeholders for the arithmetic only. They are not a measurement of any Bitaxe model. Replace them with your own.

• EXAMPLE wall draw: 18 W
• EXAMPLE average hashrate: 600 GH/s

EXAMPLE ONLY
600 GH/s ÷ 1000         = 0.6 TH/s
18 W ÷ 0.6 TH/s         = 30 J/TH

If the same EXAMPLE miner used the same power but hashed faster, J/TH would go down (better). If it used more power at the same hashrate, J/TH would go up (worse). That is the whole idea.

Ordered "work out my Bitaxe efficiency" checklist

1. Get a plug-in power meter

Symptom: You only have the power number AxeOS shows.

Fix: A plug-in energy meter between the socket and your Bitaxe power supply measures what the whole setup actually draws, including supply losses. That is the honest input for efficiency at the wall. The Bitaxe power cost post covers how to measure.

2. Let the miner warm up at your normal settings

Symptom: The numbers jump around right after boot.

Fix: Let the miner hash at your usual frequency and voltage until temperature and fan speed settle. Efficiency measured in the first few minutes is not representative.

3. Use an averaged hashrate, not an instant one

Symptom: The hashrate readout swings up and down.

Fix: Instant hashrate is noisy. Use an averaged figure — AxeOS and the Bitmern Solo dashboard both show hashrate over a window. The dashboard figure is derived from accepted shares, so it can differ from what the board reports, especially over short windows. That is explained in expected hashrate vs dashboard.

4. Convert units carefully

Symptom: Your J/TH comes out a thousand times too big or too small.

Fix: Convert GH/s to TH/s by dividing by 1000 before you divide watts by hashrate.

5. Calculate wall efficiency

Symptom: You have the inputs but no number.

Fix: Wall watts ÷ TH/s. Write the result next to the miner's name with the date and the settings you used.

6. Compare with any efficiency figure your firmware shows

Symptom: AxeOS shows a different efficiency number from yours.

Fix: Some firmware versions display an efficiency figure. It is usually based on the board's own reported power, which sits on the board's side of the power supply. Your wall figure includes the supply's losses, so it will normally look a bit worse. Both are useful: the firmware figure for trends, the wall figure for the real energy you pay for.

7. Re-measure after any change

Symptom: You changed frequency, voltage, firmware, the power supply, or the room.

Fix: Any of these can shift both power and hashrate. Re-measure after each change, one change at a time, so you know what moved the number. Firmware procedure: firmware update checklist.

8. Watch heat — throttling hurts efficiency

Symptom: Efficiency gets worse in the afternoon or in summer.

Fix: A hot chip may throttle, losing hashrate while still drawing power — that pushes J/TH up. Fix airflow before blaming the board: temperature throttle fix. If hashrate dropped suddenly, see hashrate drop fix.

9. Keep the stratum fields exactly as they are

Symptom: You wonder if a different port or pool string changes efficiency.

Fix: It does not. Efficiency is a hardware and settings question. Keep:

btc.bitmernsolo.com

Port:

3132

Username:

WALLET.worker

Password:

x

Never treat :3102 as the Bitaxe / home default.

10. Confirm the work is reaching the pool

Symptom: Your efficiency looks great on paper, but you have not checked the dashboard.

Fix: Efficiency only matters if the hashes are accepted. Open the same coin tab on Bitmern Solo and confirm the worker under WALLET.worker with fresh accepts. A miner that is rejecting or disconnected is spending energy on nothing — see dashboard workers / shares / effort.

About tuning for efficiency

Frequency and voltage settings affect both hashrate and power. Generally, pushing harder raises power and heat faster than it raises hashrate, while backing off can improve efficiency at the cost of some speed. Exactly where the balance sits depends on your board, chip, cooling, and firmware.

This post does not recommend specific frequency or voltage values. If you experiment:

1. Change one setting at a time and let it settle.
2. Measure wall watts and averaged hashrate after each change.
3. Watch temperature and stability — a setting that crashes or throttles is not efficient.
4. Follow the board maker's guidance on safe ranges, and back up your config first: AxeOS config backup.

Why efficiency is the lever you control

Solo mining is a lottery-style bet on every hash. Each hash has a tiny chance of finding a block, set by network difficulty — not by you. You cannot choose when a find happens. What you can choose is how much energy each hash costs:

1. Odds per hash — set by the network. See difficulty adjustment explained.
2. Hashes per second — set by your hardware and settings.
3. Energy per hash — that is efficiency, and it is yours to measure and improve.

Efficiency connects directly to cost: the Bitaxe power cost formula turns wall watts into money, and J/TH tells you how much work you get for those watts.

The fee only applies to finds: flat 1%, you keep 99% — see 1% fee explained. Whether solo mining fits you at all is a separate, personal question — see is a Bitaxe worth it. This is not financial advice.

Current Effort is an ops signal — not a find guarantee. Better efficiency does not change your odds per hash; it changes what each hash costs you.

What this post will not invent

• No hashrate, wattage, or J/TH figures for any specific Bitaxe model
• No overclocking or undervolting values — follow the board maker's guidance
• No profitability, ROI, or payback claims — no financial advice
• No "expected days to find" numbers
• No claim that :3102 is the home Bitaxe default (easy-start is :3132)

Common efficiency mistakes to avoid

1. Mixing GH/s and TH/s — divide GH/s by 1000 first.
2. Using a spec-sheet figure as if it were your miner — measure your own.
3. Using instant hashrate — use an averaged window.
4. Measuring right after boot — let it warm up.
5. Comparing firmware efficiency to wall efficiency as if they were the same — one excludes supply losses.
6. Changing several settings at once — you will not know what helped.
7. Ignoring rejects — rejected work is wasted energy.
8. Treating :3102 as "the Bitmern port" — easy-start for Bitaxe / home BTC is :3132.

Soft next step

Put a plug-in meter on your Bitaxe, let it warm up, note wall watts and averaged hashrate, convert to TH/s, and divide. Write your J/TH down with the date and settings. Then confirm BTC easy-start btc.bitmernsolo.com with port :3132, WALLET.worker, password x, and check the worker row on the matching coin tab.

Start mining

Start Mining — after login, open the matching coin tab and confirm workers / shares / hashrate.

FAQ

What does J/TH mean?

Joules per terahash: the energy a miner uses to compute one terahash. It equals watts divided by TH/s. Lower is more efficient.

How do I calculate my Bitaxe's efficiency?

Measure wall watts with a plug-in meter after warm-up, take an averaged hashrate, convert GH/s to TH/s by dividing by 1000, then divide watts by TH/s.

Why does AxeOS show a different efficiency than my calculation?

Some firmware versions display an efficiency figure based on the board's reported power, which excludes power-supply losses. Your wall-meter figure includes them.

What is a good J/TH for a Bitaxe?

This post does not quote figures for specific models. Measure your own, track it over time, and compare like with like — same settings, same room, same measuring method.

Does the stratum port affect efficiency?

No. Efficiency depends on hardware and settings. Keep :3132 on btc.bitmernsolo.com; never treat :3102 as the Bitaxe / home default.

Does Current Effort mean I am about to find a block?

No. Current Effort is an ops / attribution signal — not a find guarantee. See Current Effort explained.