My gpu usage is not stable !

[timetsami]

hi everybody,

i have got a problem with my two sapphire 7950 when i launch guimier

after 5 min the gpu usage begin to change between 64 % and 100 %
img : http://imageshack.com/a/img36/2666/aly7.png

specs : soft ; w7, catalyst 13.4
           hard : asrock 970 Extreme4, amd sempron 145, 4gb, psu 850w gold+

thx for your help

[Xch4ng3]

What settings are you using for GUIminer?