Figured I'd post this here just in case you run into a similar situation during your build.
Since I'm about to cram 4 more CPU cores into the same case I'm running now (going from 8 to 12 cores) I figured I'd better finally do something about my cooling. My machine starts out fine after it's been off for an hour, but after a while the fans start running fast and faster. Basically it seems to be heat soaking. In an effort from Supermicro to keep the case quite, they didn't put an exhaust fan on the rear, but instead lined the front of the case with 4 intake fans, and provided a air shroud to move the air over the passive CPU heat sinks. The problem is, I put a Tyan board in the Supermicro case. So the shroud the included didn't line up with anything. So I put fans on each of my CPUs, but they just get the heat up into the case, not out. There's an optional rear fan from Supermicro, but it's a 4-pin PWM fan--it's an odd size, and a standard fan won't fit. The problem comes up that I don't have any more PWM headers on my board.
I had theorized that providing the power to the fan, along with splitting the PWM lead would allow to fans to be run from one header--the RPM monitor should only be connected from one fan (else a 2x reading would be returned). I just now found a company which makes just what I needed the
Ak-CB002. This allows one 4-pin PWM header to be still connected to the fan to be monitored (like the CPU fan), in addition two more fans get the same speed setting from the split PWM lead. And as to not tax the somewhat fragile board header the power for the fans comes directly from the power supply. Brilliant. I ordered 3 of them.
