AMD 8950 GPU load

I build up a system to run hashcat. i7, 16gb mem, ssd and amd radeon hd 8950. what i notice actually is that the GPU load is fluctuating, from values between 60 and 100%. this happens even when the gpu is at a low temperature (68 degrees). is this behavior expected or is there something i can do to make the load always 100%??

PS running windows 7, and started with a fresh install with bare minimums, didn't get it to run on linux yet.
depends on which version of hashcat you are using, what algorithm you are attacking, what attack modes you are running, what your -n and -u values are. maybe you can provide more information about what you are doing. otherwise i suggest getting more familiar with the software. read the wiki, read the forums.
I played for a little while with a couple of -n and -u values, from small to big (first the tuning and then the fine tuning). I see the fluctuations mostly with the dictionary attack. could it be that the system is reading the dictionary and letting the gpu wait?
you cannot achieve full acceleration with a straight wordlist attack against fast hashes. you need to add some rules.