temperature questions

I've been checking out my Oc'ed Sapphire 4870 1gb, and the temps are kind of high (at least I think so) right now it's 74 degrees Celsius (idle) with 18 percent fan speed... I'm using xpert tools to monitor it and the fan mode is set to dynamic, and basically the options aren't good enough for me cause if I go to a custom fan speed the lowest it has is 50 percent and that's too loud, is there anything I can use beside ati traytools (because it won't recognize my fan) to put the fan at something that will keep it cool while not gaming and cool while gaming cause this is bugging me

p.s. I can get it to around 48 degrees celcius idle at 50 percent fan speed which I'm going to do for now cause I don't want my gpu cooking itself to death

p.s.s. graphics card just got too cold and crashed my system? ahhh idk screw it I need help (not going 50 percent speed anymore obviously) this is actually kind of funny