Very very smallest the cracking speed 7870 XT

[loveistheair]

I have

GPU 1
Ati Radeon HD7870 XT With Boost (Tahiti core 7950/2 ( share on 2) = my 7870)

Program to recover WPA/WPA2 passcape and elcomsoft give me speed about 120000-160000 pass/s

oslHashCatGui give me 49312 pass/s
Seems there in oclHashCat is a special limitation on the graphics card

How to remove this limit and who made it and for what???

2 And anyway very small speed on all card less than other programs (passcape and elcomsoft ) on 5000-10000 pass/s

How to contact the developer on this subject?