The Ethereum blockchain underwent its historic transition from Proof-of-Work (PoW) to Proof-of-Stake (PoS) at exactly 2:43 AM EST with the mining of block 15,537,393. This milestone marked the end of Ethereum's mining era and ushered in a new chapter powered by validators. Remarkably, this fundamental shift occurred seamlessly within 12 seconds without any network downtime. Here's our detailed analysis of critical events surrounding The Merge.
The Final Countdown to TTD
The transition began when the network reached Total Terminal Difficulty (TTD). Key observations:
- Hashrate remained stable during PoW's final day, ensuring TTD completion within expected timelines
- CoinMetrics' FARUM detected 6 chain reorganizations in the 2-hour window pre-merge
- Mining pool f2Pool produced the last PoW block at height 15,537,393
Network Health Monitoring
We established real-time visualization tracking consensus layer health via Lighthouse nodes, displaying:
- Epoch slot status (32 slots/epoch, 12-second intervals)
- Green slots: Successful block proposals by randomly selected validators
- Red slots: Missed blocks (typically from validator downtime or client misconfigurations)
A small percentage of missed slots is normal, but sudden spikes indicate network issues - as briefly seen during the September 6 Bellatrix hard fork.
Merge Execution Metrics
The transition succeeded with:
- 99.98% block proposal success rate during merge epochs
- Only 2 missed slots observed post-TTD across 4,700,013-4,700,015 epochs
- Full network confirmation within 13 minutes
- Seamless integration of execution payloads into beacon chain
Post-merge data shows:
- Error slot ratios matching pre-merge baselines
- Predictable 12-second block times (versus PoW's probabilistic timing)
- Several validator operational issues emerged (discussed below)
Chain-Level Impacts
Final PoW Block Highlights
- Contained an NFT bundle transaction
- Proposing validator (#347963) earned ~45 ETH in rewards
Validator Payment Issues
We identified:
- 15+ post-merge blocks with misconfigured fee recipients
- Fees accidentally burned when sent to
0x000000...addresses - Caused by unset/incorrect validator payout addresses
First Post-Merge Slashing
Validator #404680 was penalized in slot 4,700,025 for:
- Running duplicate validator instances
- Common operator error when attempting redundancy
- Highlighting the importance of proper node configuration
The Miner Transition
Ethereum's 7-year PoW era saw:
- $35+ billion in total mining revenue
- ~50 million ETH mined (of current 120M circulating supply)
Current challenges for GPU miners:
- Plummeting hardware values
- Unviable alternatives (ETC daily revenue = 1/40th pre-merge ETH)
- Some miners attempting ETC transition despite 90%+ difficulty spike
Historical Perspective
The 2014 Ethereum whitepaper first proposed PoS transition as a future possibility. Achieving this:
- Required global coordination
- Maintained 100% uptime
- Represents unprecedented blockchain evolution
Ethereum Merge FAQ
What was the exact moment of The Merge?
Precisely at block 15,537,393 (2:43 AM EST) when TTD was reached.
How quickly did the transition occur?
Full transition completed in 12 seconds without network interruption.
What happens to GPU miners now?
👉 Learn about alternative mining options as Ethereum mining becomes obsolete.
Were there any major network issues during The Merge?
Only minor slot misses observed (0.02% error rate), matching pre-merge performance.
How does PoS improve Ethereum?
Enables:
- 99.95% reduced energy consumption
- Predictable 12-second block times
- Stronger economic security
Can validators lose ETH?
Yes - improper setup can lead to:
- Missed rewards
- Slashing penalties (e.g., duplicate validators)
For deeper technical insights, explore our 👉 complete validator setup guide.