Key Features

• Add Mining Efficiency technology that reduce the ore consumed by all mining drills
• Default maximum level: 20
• Reaching the max level effectively multiplies ore yield by ×100
• Miner speed is affected by quality: 1 + (level × 0.3)
• Quality does not affect the resource drain percentage
• Research cost scales with power of 3 in the late game. The closer you get to the max level, the more effective each level becomes (add extra levels to increase difficulty)

Gameplay Impact

• Solves the issue where mining productivity makes drills insanely fast
• Mining drills must actually work - ore patches size matter
• Makes extra oil mining outpost relevant in late game
• Makes productivity modules in mining drills meaningful
  • Design proper beaconed mining setups
  • Productivity is multiplicative. At max level, +100% productivity results in ×200 total ore

Technical Notes

• Removes the vanilla Mining Productivity technology by default
• UPS impact is almost zero
  • Only runs on research completion (O(n))
  • Or when an entity is built (O(1))
• Still beta and not fully tested

Known issue

• Special Mining drills are not hidden: https://forums.factorio.com/viewtopic.php?t=132058

Commands

• /mdrd_unresearch
  Before removing the mod, Prevents mining drills from disappearing.
• /mdrd_refresh
  If some mining drills do not upgrade
• /mdrd_list_effects
  Help to understand how effective resource drain is for each mining drill

Links

• Original brainstorming discussion

Extra

• Dev time used: 2 big days