Yes, they are 3 pin fans, and are actually connected to a 10v reducer cable (into a splitter if that makes a difference) to make then 1600 RPM from the default 2000 RPM. my temps are really low already though so looking to go further.
And yes, that option is in my Bios. it's currently either on auto or pwm though, definitely not via voltage! and yeah, I have speedfan too, it looks really good but I thought I'd start with getting smartfan working first, so I know I can actually alter the speeds.
Out of curiosity does it matter which three of the four pins in the CPU fan header I plug my three pin cables into? Currently have them in the last three, rather the first three.
Thanks for the help, I'll set it to voltage mode and hopefully it'll let me slow things down. My CPU and rear exhaust fan are pretty loud and it'd be nice to slow them down!