Limit DAG growth Discussion


#1
ECIP: 
    Title: Fixed DAG limit restriction 
    Author: Cody Burns <[email protected]>
    Status: Draft
    Type: Standard
    Created: 2018-04-16

ECIP-1043– Fixed DAG limit restriction

Abstract

The purpose of this ECIP is to set a limit on the maximum size of the DAG to its initial state and no longer increase it on an epoch schedule

Motivation

The original intent of the DAG was to provide ASIC resistance to the mining protocol in order to prevent centralization of mining distributions and thereby provide for an objectively fair distribution of tokens. As evident by ASICs being developed that are capable of matching current GPU miners while being more energy efficient, the DAG has failed at its task and now only serves as a deterrent to broader investment in application specific hardware by competent distributors. Because of this, the increasing DAG has began to have negative impact on long term security and acts as an anti-competitive bug preventing large scale investment in mining development .

As originally discussed in ECIP-? Limit DAG growth #6; a constantly increasing DAG will eventually reach a hard limit of bus speed on GPU memory and forcing GPU’s into obsolesce does not provide an increase in security. To the contrary, smaller DAG sizes allow more GPU’s the ability to mine while providing a lowered initial entry cost to hobbyist miners.

A 5 year vision of the mining landscape would see a transition from general purpose GPU mining to a broader market of application specific hardware being built by current and supported by a diverse group of manufactures similar to the current GPU market.

Specification

if(blkNumber > forkblock) DAG epoch = 0

Risks consideration

This ECIP is not forward compatible and introduces backwards incompatibilities in the DAG file generation, block verification, and block mining. Therefore, it should be included in a scheduled hardfork at a certain block number.

This is a long term PRO applicaton specific hardware proposal. If sufficient interest is not generated by manufactures in the mining field, there is risk of domination by one or more manufactures. (market risk)

Implementation

The following clients implemented ECIP

  • [] Geth-ETC
  • [] Parity
  • [] Mantis

Copyright

Copyright and related rights waived via CC0.

Github link: https://github.com/ethereumproject/ECIPs/pull/91