I'm curious to start making my own recipes, and am thinking about trying 1 gallon batches. I would guess the conditioning time would be the same, since by then it's all in it's own bottles, so there's no difference there from the 5 gallon batch (just fewer bottles). However Is the fermentation and settling time the same for a small batch vs a full 5 gallon batch?
To answer your question it is important that you first understand what it is that the yeast is actually doing whilst in the "fermentation stage".
After you have added your yeast to your batch it will begin with a so called lag phase. This is mainly the yeast getting climatised with the new environment. In this phase the yeast also start to take up minerals and amino acids from the beer, this to get to the amount of nutrients it needs in order to complete the fermentation. If the wort does not have enough the yeast will have to start to produce its own nutrients. So depending on the quality of the wort this time will differ. The entire lag phase can differ from anywhere between a few hours up to 15-24 hours. Until this phase is completed, the yeast will no yet start to ferment.
The next phase is the growth of the yeast, during this phase the yeast will consume the sugars in the brew; producing CO2 and alcohol. During this phase the flavour compund is also produced, meaning that this phase is the most important part of your brew. Not only is it significant for the alcohol content of your beer, but it also affects it impacts the falvour greatly. This phase usually takes between 1 to 4 days.
During the final phase of the process the growth of yeast is slowed down and the beer reaches a maturing phase. The yeast now starts to "flocculate" (basically it is settling down). It is during this phase it is important to make sure that the beer has reached its final gravity. If it has not, and the yeast has started flocculating before it has reached it's terminal gravity, it has to be "roused" to ensure that it fully consumes all the fermentable sugars. This process takes at least three days, and can be left here for maturing.
If you wish to speed up the process it is possible to increase the initial yeast/sugar-ratio. This will introduce more yeast that can quicker consume the sugars in the wort, however this will also decrease the possibility for each yeast to reach the optimum level of nutrients it needs in order to fully ferment the beer. Meaning that each yeast will be less healthy in this case. To reach an amount of yeast that is pitched that reduces the quality (or health) of the yeast is however unlikely when homebrewing.
If you introduce the same amount of yeast in a smaller batch you will see a reduction in the second phase since you introduce more yeast particles to consume the sugars. You might however see a slightly longer lag phase, since it will take longer for the yeast to acclimatise itself.