This is a trivial issue, but caused me some confusion trying to find the cause of low FPS while debugging a mission.
My test results (using hint):
String length, FPS
1, 118
2, 118
4, 118
8, 118
16, 118
32, 118
64, 117
128, 116
256, 114
512, 111
1024, 100
2048, 75
4096, 40
8192, 14
16384, 4
32768, <1
65536, <1
131072, (Arma3.exe not responding)