Gem Overclocker - Build Times don't Add up

[OneloneZanzibar]

Item	Production Building	Lubricant	Gems	Build Speed	Build Time
HyperComputer Module	Advanced Assembler	None	None	1x	2304
HyperComputer Module	Advanced Assembler	None	Sapphire Seed	1.2x	1986
HyperComputer Module	Advanced Assembler	None	Emerald Express	1.35x	1800
HyperComputer Module	Advanced Assembler	None	Diamond Dark	2x	1280
HyperComputer Module	Advanced Assembler	Ultra Lubricant	None	1x	166
HyperComputer Module	Advanced Assembler	Ultra Lubricant	Sapphire Seed	1.2x	165
HyperComputer Module	Advanced Assembler	Ultra Lubricant	Emerald Express	1.35x	163
HyperComputer Module	Advanced Assembler	Ultra Lubricant	Diamond Dark	2x	157

Maybe my game is bugged, but I don't see the speed reduction that the game says I should have when slotting a Diamond Dark gem.

[Vahnkiljoy]

You would think 1.5x would be noticeable, they REALLY should just make it 2.0x so the end game isn't such a stupid slog, here I am in the overlay responding and about to just do stuff while I wait, this feels worse than forager.

[Delreich]

Speed-ups are additive. Lubricant speedups are off-by-one.

Base time for HCM is 2880 (90 * 32).
+25% skills gets it to 2304. (2880 / 1.25)
+100% OC gets it to 1280. (2880 / 2.25)
+1600% lubricant -> 157.81. (2880 / 18.25)