KalimochoAz/android_packages_apps_Contacts — comment on commit 2097e4e8858978ef3adf14aed7e7319735002cbf
File:  line 0
By pawitp:

Comparing English-only vs all, the performance difference is very negligible (10 ms for converting 1000 names) on 800 MHz (which is likely the lowest ICS will run on). Yes, other languages will need other settings, but I would like to keep Roman languages grouped together due to the reason mentioned before (having foreign name).