OK Ive been searching the forum trying to find a suitable thread to read to give me some answer but I cant find one Anyway...... mac pro runs sweet as. Today I "attempted" to install Apples RAID Card into the machine. Despite the instructions being for the older Mac Pro's, it was pretty easy ( well except the ipass cable thing which is no where to be seen on the new mac's ). Everything powers up fine, computer see's the raid card etc... But the problem is my FAN. As soon as the computer starts to boot, the fan kick into 5000rpm. I checked all the temps etc and everything is running fine, but for some reason the fan wont slow / switch off. Now, if I remove the RAID card, the fan returns to normal use. Rinse and repeated this a few times and the fan only goes into overdrive when the RAID card is installed. Any thoughts, observations, ideas?