loose file and optimization question

[youtoo]

I have read lots of docs and videos. However, I am confused about this.

 

What is meant by a 'bsa' vs. a loose file? Or do I not have this correct? Is a loose file an unzip or something?

Is this related to using ddsopt to optimize textures?

 

I have read alot of stuff, but Im confused.

[rootsrat]

BSA is like a zip file, yes. Loose files means the BSA is unpacked.

 

When you launch Skyrim, the loose files ALWAYS overwrite the BSA files. So for example if you install texture mod in loose files, and then install other textures mod (that covers the same stuff) after it, but in BSA format, then the first mod would be what you see in game, even though in theory the last one installed should be what you see.

 

Using BSA however has it's benefits, especially in regards to access time (the data is read faster by the game if it's back into the BSA, or this is my understanding at least).

[EssArrBee]

Actually, I think reading the unpacked file is a bit faster, but since Bethesda designed their own archives and the engine has native support for the BSAs, there is basically zero cost. If an asset is not in RAM and has to be retrieved from disk then we are talking about thousands or clock cycles, packed or unpacked. The best reason for using a BSA is saving space. The only time I unpack then is if it saves an esp slot.