Dell PowerEdge C6145 questions: fan control, each motherboard runs separately or together?

I got my hands on a (two, actually) Dell PowerEdge C6145 servers, equipped with two motherboard trays each with four AMD Opteron 6282 SE CPUs (140W). It works, I did boot it up earlier today, but I’m a bit confused how to run them, and can’t seem to find much about them online or reports of anyone else using one. Basically here’s what I’d like to know:

  • Do the two motherboards run completely independent of each other, like two separate computers? Does each one boot up separately? Or do they share RAM, CPU, storage, etc? Like, can they be combined to operate as one single 128 core unit? Or can they only be combined as a cluster like you’d combine separate physical servers?

  • The fans on mine quiet down during POST and then go to near full speed when the monitor turns on. Does this mean there is some sensor or other fault that the server is responding to by sending the fans full tilt? Or is this normal fan behavior for a machine like this?

  • On a related note, what kind of fan control do these systems have? The fan control board has jumpers to set the fan speed, but from what I read the minimum you can do with that is 6300RPM, which is still a crazy lot. Can they be made to go lower? Is it possible to hack the fan system on this, by manually reducing the speed and either jumping or faking the tachometer? (I’ll monitor temperature of course). I read about someone replacing the fans on these, but he didn’t mention how - what kind of fans would work, and do I need to mess with the tachometer?

  • lastly what are some cool things I can do with 128 CPU cores?

Thanks in advance!