Hi everyone, I have an original Mac Pro (2x Dual-core 3Ghz); from what I have heard other say, these things are whisper-silent Macs. My brother's 8-core 2008 Mac Pro seems VERY quiet, even while full of dust, HDDs, and a GPU that has a cooling fan. Mine, however, seems like it's louder than it should be - it's definitely louder (and sounds different) from my brother's 2008 Mac Pro. First off, I DO have an ATI Radeon 5770 on this, so that does contribute to the noise the machine makes. However, I can distinguish its noise from my computer's fans' noise. I also only have one HDD in this machine - just FYI. What's catching my attention is the frontal fan. It seems to be a bit loud; and rather than giving off a very faint hum, much like how it is on that '08 Mac Pro, it sort of sounds like a mini wind tunnel. In no way is it a blasting or dangerous-sounding noise, but it is a little louder than how quiet people say these are. It almost sounds like... like... if you pucker your lips / prepare to whistle, but steadily and carefully blow air out without making the whistling noise (or perhaps on the verge of a whistle). It's not a buffeting fan noise, but it does sort of sound like air escaping from a narrow passageway. I have reset the SMC (by way of shutting down and unplugging everything), and the PRAM as well. This hasn't done anything. My temps are pretty nice, and my fans all run at 500-600 RPM, respectively. I have noticed a few things, though, and they may or may not be contributing factors. For one, the power cable for my GPU is a little bit long, and it does stand in the pathway of the airflow--almost directly behind this front fan - where those racks are for extra-long GPUs (and where it plugs in). I also put a small LED light strip in this machine, and it is hanging freely where the GPU is and possibly altering air flow(?) Lastly (and a bit obviously), there is some dust on the tips of the blades of this frontal fan. I have cleaned this thing before, but I cannot remember when the last time was and if it made a difference, or whether or not I had still had my fan-less card at the time. It seems like cleaning dust has never made audible differences for me, at least with the general lot of my computers. In the meantime, though, I'm taking a 3-gallon air compressor to this thing tomorrow. If that doesn't clear things up, I'll be back. If it really doesn't help, what could it be? Oil the fan? Not one Mac Pro is alike? Did I happen to get a model with a slightly louder fan? Much appreciated, -MDD P.S. It's 2:20 AM at the time I am writing this, so excuse any errors if you see 'em.