Currently Sublimetext 3 can open large files (about 500mb for example) but:
- It takes very long
- and searching inside takes very long, too
In comparision there are other editors (UltraEdit) which opens such files instantly.
* Do not load the complete file into memory when it's larger than X MB. Just load the first X MB only.
* Continue loading when the user scrolls down or the search needs to load more up to the next occurance of the search.