Cubic Diodes farming guide
Europa — Larzac (Dark Sector Defense)
Cubic Diodes drop from Eximus units on Europa, and this Dark Sector Defense stacks its resource drop-chance bonus on top of the Eximus spawns that ramp up with waves — the wiki cites 100+ Cubic Diodes by wave 20.
Boosters help: this spot relies on enemy drop tables.
Neptune Proxima — Nu-gua Mines (Railjack)
Cubic Diodes are significantly more common in Empyrean than on Europa: Corpus Proxima end-of-mission bonuses can award 200 at once, and sweeping the storage containers at points of interest like Nu-gua Mines adds more — a container/reward farm, so drop boosters don’t apply.
Boosters don't apply: this spot is a container/deposit pickup, not an enemy drop.
Early game
Larzac on Europa (Dark Sector Defense) is the go-to ground farm: Cubic Diodes drop from Eximus units on Europa, and Eximus spawns scale up the longer a Defense runs — the wiki cites 100+ Cubic Diodes by wave 20 here. The Dark Sector resource drop-chance bonus and Resource Drop Boosters both apply, since everything comes from enemy drop tables. Ose (Interception) is a decent alternative if you prefer that mission type.
Mid & late game
Once you have a Railjack, Corpus Proxima is in a different league: Cubic Diodes are significantly more common in Empyrean than on the Corpus Ice Planet tileset. End-of-mission bonuses across Venus, Neptune and Pluto Proxima can award 200 Cubic Diodes at once, and sweeping the storage containers at points of interest like Nu-gua Mines (Neptune Proxima) stacks more on top — container and mission-reward payouts, so drop boosters don’t help there.