Comment 20 for bug 156201

It’s been nearly a decade now and this is still an issue… Micro$oft engineers must be making jokes about this. Editing a 5MB text file should not be a problem.
Seriously though, my intuition is that it can be narrowed down to the system displaying Unicode characters as their double byte code in one character space. Maybe, the approach should be to use one single generic “U” in a small rectangle as the only graphical representation of unknown characters. I doubt it is of vital importance to display the exact Unicode value of special characters. Users who need this kind of information probably use specialize tools already.
As for me, I gave up. Now I use Bless Hex Editor when it comes to text files containing blobs and such.

As an example I attached a mysqldump file containing a single row insert with about 3MB blob data. Such a file is impossible to edit using gedit 3.18.3 in Ubuntu 16.04 with a 6 core CPU, 12GB RAM and a SSD drive. gedit just hogs an entire core and slowly eats up RAM (250MB after 5 minutes of processing and it keeps on rising).