Miner Health Check: Is Your Miner Performing Well?

How do you know if your ASIC miner is actually performing at 100%? The SoloFury dashboard gives you all the data you need. This guide teaches you how to read the Diff column, calculate expected performance, and spot problems before they cost you money.

1. Understanding Dashboard Columns

When you enter your wallet address on the SoloFury dashboard, you see a worker table with these columns:

2. What is "Diff" and Why It Matters

The Diff (difficulty) column shows the current share difficulty assigned to your worker by the pool's VarDiff (Variable Difficulty) algorithm.

Here's the key insight: the Diff value is directly proportional to your miner's actual hashrate. A miner performing at full speed will have a higher Diff than a miner that's underperforming.

3. How VarDiff Works

VarDiff automatically adjusts the difficulty for each worker to keep share submissions at a steady rate. Here's how:

1. When a miner first connects, it starts at startdiff (SoloFury default: 100,000)
2. If the miner submits shares too frequently, VarDiff increases the difficulty
3. If the miner submits shares too slowly, VarDiff decreases the difficulty
4. The target is approximately 1 share every 10 seconds (SoloFury's update interval)

For a powerful ASIC miner (like an Antminer S21+ at 235 TH/s), VarDiff will quickly ramp up the difficulty from 100,000 to 300,000+ because the miner produces hashes so fast that low-difficulty shares would flood the pool.

Difficulty timeline for a new S21+ connection:

4. The Performance Formula

You can calculate the expected steady-state difficulty for any miner using this formula:

SoloFury's update interval is 10 seconds. So:

5. Real-World Examples

Here is an example of 4 identical Antminer S21+ units mining BCH on SoloFury:

Example 1: All miners performing well

Analysis:

• Top performers (0310, 0210): Diff ~340K — running at full capacity
• 0110: Diff ~302K — about 11% below top performers
• 0410: Diff ~288K — about 15% below top performers

How to calculate the performance gap:

For Miner-D vs Miner-A:

Gap = (1 - 287,598 / 343,687) × 100 = 16.3%

This means Miner-D is performing 16.3% below the best unit. That's significant — it means 16.3% fewer hashes, 16.3% fewer chances of finding a block.

Example 2: A miner with problems

In this scenario, one miner is clearly underperforming:

Red flags:

• Diff stuck at 100,000 (startdiff) — VarDiff never ramped up because the miner kept disconnecting
• 3x more disconnections than healthy miners in 24 hours
• Significantly fewer shares compared to the healthy miner

6. Comparing Multiple Miners

The most reliable way to check miner health is to compare identical miners to each other. Here's the method:

7. Warning Signs — When Something is Wrong

🔴 Diff stuck at startdiff (100,000)

Cause: The miner is connecting and disconnecting rapidly. VarDiff never gets a chance to ramp up because each new connection starts fresh at startdiff.

Common reasons: Loose internal connections, dust buildup causing overheating, firmware bugs, or network instability.

🔴 Last Share more than 5 minutes ago

Cause: The miner stopped submitting shares. It may have crashed, lost internet, or a hashboard failed.

Action: Check the miner's web interface. If it shows "Connected" but no shares, restart the miner.

🟡 Diff oscillating between high and low values

Cause: This is normal for Antminer S21+ units. Each S21+ has 3 hashboards, and each opens its own stratum connection. The firmware performs periodic reconnections (~every 7 minutes). When a hashboard reconnects, it starts at startdiff (100K) and ramps back up. The displayed Diff is from the last share received, which could be from any of the 3 connections.

Action: Nothing — this is expected behavior. The mining continues normally during reconnections.

🟡 One miner has 50%+ more disconnections than others

Cause: Hardware issue, likely a loose connection between hashboard and control board.

Action: Perform physical maintenance: clean dust, reseat ribbon cables between hashboards and the control board.

🟢 Diff values fluctuate within 10% of each other

This is normal. VarDiff continuously adjusts, and shares have natural variance. A 10% fluctuation between readings is expected.

8. What To Do When Performance is Low

If you host your own miners:

1. Check temperature — overheating causes throttling. Clean dust from fans and heatsinks
2. Reseat ribbon cables — disconnect and reconnect the cables between hashboards and the control board
3. Update firmware — outdated firmware can have bugs that cause performance issues
4. Check power supply — insufficient or unstable power causes hashrate drops
5. Restart the miner — a full power cycle can resolve many issues

If someone else manages your miners:

1. Share the data — show the Diff comparison between your miners with exact numbers
2. Quantify the gap — "Miner A runs at 340K diff while Miner B only reaches 290K — that's 15% below"
3. Explain the impact — "In solo mining, 15% less performance means 15% fewer chances of finding a block"
4. Request maintenance — cleaning, cable reseating, and firmware check usually resolve the issue

Related Guides

• Solo Start Complete Guide
• Antminer S21+ Setup Guide
• How to Solo Mine BCH