The Research Slider

Sometimes in the very early game, particularly when I'm playing at Emperor or above, it seems that I cannot affect the pace of my research no matter where I put the research slider. It is the same # of turns to gain the tech at 10% or 90%. Eventually with more cities it becomes adjustable, but not early on. This might not be enough information to answer the question, but does anyone have any ideas why this is?

 

I'm pretty sure it is related to difficulty/Civ size then. On lower difficulties, sometimes a 10% change won't affect it, but anything more will. I assume that the higher the difficulty, you need more research "base" first.

 

If you're gaining 4commerce/turn after you found your first city, whether the slider is at 100% (4beakers/turn), or 50% (2bpt), it'll still take the 50 turn max to finish a 200 beaker tech. Later you will be researching at a per turn rate that is a higher percentage of the research cost of a tech than you are at the beginning of the game, so adjustments are more meaningful. You also gain a more nuanced control via micromanagement.

 

The main two factors are the map sizes and the cost factor. The cost factor is a function of the level of difficulty. Minor adjustments are used such has how many civs you know that know the tech being researched. At the start you may not know any civs that know the tech you are researching. The larger the map the higher the tech cost. The higher the level the higher the cost.

Std maps factor is 240 and emp CF is 8. Note that as the difficulty level goes up the cf actually goes down, but raises the cost. Regent cf is 10, while sid is 4.

Research Cost = [MM * [10*COST * (1 - N/[CL*1.75])]/(CF * 10)] - Research done so far

MM map size, N number of civs on diplo screen that know the tech, CL = number of civs left in the game,
COST = technology cost as on the civilization advances tab in the editor,
CF = AI cost factor(as on the difficulty tab in the editor).

So like jarred said, the tech now cost more at emp than you were use to paying and the beakers you can generate at the start are too low to make an impact. Note that at the start you cannot drop below 20% and research, unless you have a scientist running.

 

The time for researching a tech is limited to 4 turn as the minimum and 50 turns as the maximum. You cannot use up more than 50 turns of actual research, no matter how little you spend, as long as you spend more than zero.

As beakers per turn do increase most techs are achievable in less than 50 turns. Aiming for 50 turns does hardly ever make sense, but exceptions do exist.

 

Another aspect that occurs in the very early game is the rounding/truncation calculations that occur when converting your raw commerce into science (beakers). Some of those calculations use the "FLOOR" function, to produce an integer result that drops the fractional parts.

In the very early game, you may find not much difference mathematically between 10% of your commerce and 90% of your commerce. As you get more cities up and running, the amount of raw commerce your cities generate will be larger and the rounding errors become less significant. Avoiding these rounding errors is the motivation for some players to use "binary" research -- either as close to 100% as they can, burning gold surplus, or as close to 0% to build up that gold surplus.