The best fans for my S3's are Corsair SP150 performance edition blowing in and Enermax UCMAA12A blowing out. The Enermax are not PWM but have a choice of three speed settings. I use the lowest 1000rpm setting. The S3 temps hover around 48-50C at ambient 22C and are a rock solid 440Gh at 218.75 Mhz, very quiet too. For lower temperatures I use Thermalright TY-143 both ends, not so quiet but easy to live with and the S3 temperature drops to 44-45C