HIS GPU's iTurbo vs Catalyst Control Center for overclocking

Seth L

Honorable
Dec 1, 2014
121
1
10,710
Before I ask my question, I'd like to say something... Odd...
I have the HIS R7 250X iCooler 1GB GDDR5 GPU
While attempting to overclock, I tried the software HIS gives you(you know, kind of obvious you'd use THEIR software, right?) Wrong.
Stock speeds are
Core clock: 1000MHz
Memory clock: 1100MHz

Ok, now... On iTurbo, I got to 1050MHz on the core clock, and 1175MHz on the memory clock before my graphics driver crashed. Instantly.

Now, when using Catalyst Control Center to overclock, I got up to 1090MHz on the core clock, 1250MHz on the memory clock. Solid 24 hours of stability. No joke.

Now as for my question... Why would CCC work better at overclocking than the software HIS designed for their hardware? Any ideas? I'd really like to know.
 

Seth L

Honorable
Dec 1, 2014
121
1
10,710
Yes, I'm using iTurbo 1.6.6

As for the temps, I used 3DMark Fire Strike(regular, not extreme or ultra) to put it under stress quickly, and I ran GPU-Z to monitor on a 0.1 second interval, here's what I peaked at:

59°C auto fan
54°C 100% fan