InStr is very slow especially when you use TextCompare. InStr doesn't even use any special technique to perform the search, it does it the hard brute force way (ie. checks every single byte). So that is why I coded something that is faster than InStr in many normal search situatations; and knowing InStr is most likely coded in ASM, it isn't a bad result. Though the main aim with my function was to provide a search function for byte arrays; beating InStr was a secondary goal.

Btw, there are some people who have made ThunderVB, which allows adding ASM code into a VB6 app. Afaik they've made InStr replacement using Boyer-Moore, which should beat the native InStr in about every possible case.