PCIe x16 vs. x8, x4, x1 | TechPowerUp Forums
If you're still using a computer with a PCI or AGP slot, it's likely time to upgrade your PC!
Permanent upgrade slot | Fandom
This is the best permanent upgrade slot build, I would not recommend the golden cookie frequency upgrade because you get all these upgrades in 8 minutes and the upgrades that I just said take more time to get.
CookieClicker Upgrades | PDF
Icon Upgrade Cost New Prerequisites Residual Luck 99 999 - Permanent Upgrade Slot 2 20 000 - Decisive Fate 7 777.