Due to some Error102/Patchdata problems I'm currently reinstalling ESO. When Steam had downloaded the 67GB-ish game, I started the launcher and it goes on to install the game.

For those that have installed the game and might remember better than me, what I would like to know is:

Does the launcher really need to download the shown amount of data again? From earlier installations, I thought I remembered that when actually installing the game from within the launcher, the whole thing went alot faster since it "downloaded" the file from some folders on the PC, rather than from some servers. Meaning that the installation speed was determined by the reading/writing speed on my SSD, rather than my internet speed.

I was unsure how to formulate my question, but if you understood my concern, I would really appreciate any input to whether the speed of your own ESO installation was determined by your internet speed, or your storage device's speed

Might the reason from this be that I moved the "Zenimax Online" folder (after fully downloading it) from the Steam Library Folder on my SSD to the Steam Library Folder on another internal HD (which is my standard - I got no clue why it wasn't downloaded to this place in the first place)? If so, is there any way to point Steam/ESO to the place all the corrent datafiles are, to prevent the launcher from having to redownload everything again?

(Yes - about 900 KB/s is maximum download speed here)