8hrs and counting for switching platform

Its been 8hrs and it looks like only 50% done to swtichiing to ios platform from pc.
Why does this takes so much time. Anyway to reduce it

 

It has to reimport and compress every asset you have in the project - textures, meshes, audio, video, everything, changing formats to what's needed for the new platform (example, iOS textures use a different compression than PC textures). The more assets your project has, the longer it will take. So one way to reduce the time is to remove assets you don't need.

But there is a way to greatly reduce the time for future platform switches: the Cache Server. Install the Unity Cache Server on your network, set up every user's Unity to use it, and then whenever someone imports a new asset, it gets cached onto the server, so the next user to get that asset will have it served over the network rather than imported. This also works with changing platforms: one person will change platforms, and all their assets for that platform will be cached, so the next person to change platforms will just pull the assets from the cache.

After that, it only adds brand new assets to the cache, so everyone gets fast platform switches from that point on, plus a new team member grabbing the entire project for the first time, will get it all from the cache server rather than waiting for assets to import.