Ethereum Classic (ETC) has gone through a hard fork that heralds a new upgrade to increase miner involvement and increase security.
According to Blockscout's ETC Explorer, the ETC mainnet reached a block height of 11,700,000 on Sunday around 3:45 UTC and automatically triggered the expected Thanos upgrade.
Terry Culver, CEO of ETCLabs, told CoinDesk Thanos this was an "important milestone" as the network seeks to improve support for existing miners and attract new ones.
The Thanos protocol upgrade (ECIP-1099) in particular has reduced the size of the DAG (Directed Acyclic Graph) file to well below 4 GB, which means that 3 GB and 4 GB of graphics processors (GPUs) can dismantle the network again. With the implementation, 4GB GPUs will be supported for an additional three years, according to an ETC blog post.
This was made possible by doubling the duration of the ETC mining phase or epoch from 30,000 to 60,000 blocks, which slowed the DAG growth (which grows with each epoch).
The upgrade allows miners with 3GB and 4GB GPU systems to resume ETC mining, "which ultimately increases network security and promotes a more dispersed and healthier mining ecosystem," said Culver.
Before the upgrade, the DAG size was already very close to 4 GB, which pushed some older GPU mining cards off the network. The Thanos upgrade effectively reduced the DAG size per post from 3.94 GB to 2.47 GB.
Over 90% of the existing miners have made the move to the Thanos Fork, according to Culver. As new miners went online, the network's hashrate has also increased significantly.
ETC has seen a number of what are known as 51% attacks and is keen to take steps to make the network more resilient. One such initiative called MESS (for Modified Exponential Subjective Scoring) is supposed to make the implementation of massive blockchain "reorganizations" considerably more expensive (although its effectiveness has been questioned).
"MESS was the first step protecting the network, miners and exchanges," said Culver.
With more miners critical to creating a robust blockchain network, Culver argued that the next phase of security measures has now been successfully completed. "Thanos expands and strengthens the mining ecosystem," he said.