Famous jailbreaker and hacker Saurik has posted some comments regarding the way the Cydia jailbreak store functions and to explain why some of the processes act the way they do, specifically the black loading bar you see upon first launching Cydia.
Saurik has compared how Cydia loads data to how the App Store loads data and why they are different.
The biggest complaint seen from jailbreakers is how long Cydia takes to load their data. Jay Freeman a.k.a Saurik has posted up some comments to explain a bit better how Cydia handles packages in comparison to the App Store.
While Apple chooses to only load 25 apps on any one page, Cydia actually loads the entire database of packages in real time. This is the reason that you can scroll through so many packages at once and in one go as opposed to the App Store way of doing things which is by tapping a Load More.. button continuously to load 25 more applications.
“…Cydia, unlike the App Store (or almost any similar service), stores the entire package catalog locally. This is why it can (quite quickly, in fact) render an insanely long table with all packages in it that you can just fling your way through, while the App Store shows you 25 packages at a time with a slow “load more” button.”
Saurik went on to explain that a lot of how Cydia loads can heavily depend on what repositories have been added by you within Cydia. While Saurik has actively made suggestions as to how repos should be hosted, that does not mean or guarantee that all developers would choose that route. If a source is offline or not available, that is when you will get errors. This theory was tested by the removal all repositories from a device except the BigBoss, ModMyi, and ZodTTD. Cydia definitely loaded a lot quicker in comparison.
“Users are honestly more willing to believe they don’t have the right source installed (as to them there are so many and they think they should have all of them on their phone… there are users out there with over 50 sources installed… I can’t imagine what their refresh time must be like) than that they need to refresh some weird offline database.”
In short, if you would like your data to refresh a lot quicker, You should limit the amount of repositories you install to the ones you need. Saurik also explained that new devices with faster processors obviously speed up the process as well.