Etchash (Ethereum Classic DAG Algorithm)
ASIC ResistantEtchash is the proof-of-work algorithm used by Ethereum Classic (ETC) — a modified version of Ethash, the original Ethereum algorithm. After Ethereum switched to Proof of Stake in September 2022, Ethereum Classic retained proof-of-work mining using Etchash, making it the primary large-cap proof-of-work smart contract platform. Etchash is DAG-based, memory-hard, and GPU-friendly.
How Etchash Works
Etchash requires miners to generate a large DAG (Directed Acyclic Graph) dataset stored in GPU VRAM. The DAG is used for each hash calculation, requiring fast random memory access. The DAG grows over time with each epoch (every 60,000 blocks), currently around 3–4 GB. Etchash was modified from Ethash to grow the DAG more slowly, extending GPU compatibility longer. Memory bandwidth is the primary performance driver — GPUs with fast GDDR6/GDDR6X deliver the best Etchash hashrates.
History & Evolution
Ethereum Classic has used DAG-based proof-of-work since its inception. When Ethereum merged to PoS in September 2022, large quantities of GPU mining hardware shifted to ETC, temporarily causing a massive hashrate surge and difficulty increase. The ETC network eventually settled at a stable post-merge hashrate. Etchash remains one of the few profitable GPU mining algorithms in 2026, particularly for high-VRAM GPUs.
Hardware Requirements
Etchash is GPU-exclusive — no dedicated ASICs exist or are economically viable due to the large VRAM requirement. The best performing GPUs for Etchash are high-memory-bandwidth models: NVIDIA RTX 4090 (~135 MH/s), RTX 3080 Ti (~118 MH/s), and AMD RX 6800 XT (~64 MH/s). GPUs with less than 4 GB VRAM cannot mine Etchash. At least 6 GB is recommended; 8+ GB ensures compatibility for several years.
Compatible Mining Software
Mining Pools for Etchash
2Miners, HeroMiners, and F2Pool are the largest ETC mining pools. 2Miners offers both PPLNS (lower variance) and solo mining modes. The ETC network hashrate is predominantly GPU-driven, making pool distribution more decentralised than ASIC-dominated coins.
How to Start Mining with Etchash
- Choose hardware — Etchash is GPU-exclusive — no dedicated ASICs exist or are economically viable due to the large VRAM requirement. The best performing GPUs for Etchash are high-memory-bandwidth mod.
- Install mining software — compatible options include: lolMiner (best Etchash performance), T-Rex Miner, GMiner, NBMiner, PhoenixMiner (legacy).
- Select a pool — 2Miners, HeroMiners, and F2Pool are the largest ETC mining pools. 2Miners offers both PPLNS (lower variance) and solo mining modes. The ETC network hashrate is predominantly GPU-driven, making pool di.
- Configure stratum URL and wallet — set
stratum+tcp://pool-url:portas pool address and your ETC wallet address as the username/payout address. - Start mining and monitor — check accepted shares in the pool dashboard within 5–10 minutes of startup.
- Track profitability — use our live calculator to monitor earnings vs electricity costs.
Frequently Asked Questions
What happened to Etchash mining after Ethereum's merge?
When Ethereum switched to Proof of Stake in September 2022, millions of GPUs that had been mining ETH needed new targets. Many moved to Ethereum Classic, causing ETC's network hashrate to surge by roughly 100–200× almost overnight. Difficulty adjusted upward over subsequent weeks. Other GPUs moved to Ravencoin, Alephium, and smaller GPU-minable coins. The GPU mining landscape permanently shifted after The Merge.
How much VRAM do I need for Etchash mining?
The Etchash DAG file is currently around 3.2–3.6 GB. A minimum of 4 GB VRAM is required to mine ETC, but 6 GB is strongly recommended as the DAG will continue growing. 8+ GB ensures compatibility for at least several years. GPUs with 2–3 GB VRAM (like some older GTX 1060 variants) cannot mine Etchash and should not be purchased for this purpose.
What is the best GPU for Etchash mining in 2026?
The NVIDIA RTX 4090 delivers the highest absolute Etchash hashrate (~135 MH/s) but has the highest power draw (~300 W) and acquisition cost. For efficiency, the AMD RX 6800 XT achieves ~64 MH/s at only ~120 W, making it one of the most efficient Etchash miners per watt. The RTX 3080 Ti at ~118 MH/s balances raw hashrate and cost. Check our hardware comparison pages for current profitability data.
Is Etchash ASIC-resistant?
Etchash was designed to be ASIC-resistant through its DAG memory requirements. Mining an Etchash block requires fast, random access to a multi-gigabyte dataset that changes every 60,000 blocks — making it impractical to implement without large VRAM, which is expensive in ASIC silicon. No viable Etchash ASICs have entered widespread production, and the algorithm is expected to remain GPU-dominated for the foreseeable future.
How does Etchash compare to Ethash?
Etchash and Ethash are nearly identical algorithms. The primary difference is the DAG growth rate — Etchash grows more slowly, extending GPU compatibility beyond what would have occurred with the original Ethash parameters. Both algorithms require the same software (lolMiner, T-Rex, etc.) and the same GPU VRAM minimums. Miners who were mining ETH before The Merge could switch to ETC with zero configuration changes except the pool endpoint.