I got the Dremel out and started shaving back the mounting holes for the CPU bracket. I think I can make it work. But on my last shave, I got a little impatient and made a cut bigger than I wanted. It wasn't damaging, but I realized I'm too groggy.

Anyway, I'll add pictures tomorrow and maybe continue on.

I've been assuming all along that the problem was the cpu fans. I did another search and came up with someone who installed a Zalman: here and write-up here.

One of the pictures had a closeup of the case fan, so I searched for it and here is a description: here:

If noise issue is no problem for you, you might want to consider this Delta 120mm fan. It features a whopping 152 CFM of airflow at 53 dBa. For a 120mm fan that is 38mm thick that isn't too shabby. This high end Delta 120mm fan is often used in rackmount server rooms where noise is not an issue.

I can't swear, but I think the CPU fan is a:

Tach output, 9 blade, very high performance 40CFM, moderate noise 38dBA,

Okay, it is clear Sun was getting a good deal on server room fans and not desktop fans.

But, as a server, these things kick butt!

If I wanted to keep the stock fans, I think I would look into building a box to house the computer. I've looked at noise dampening from an audio perspective (think garage band) and it looks like a simple box with 2 layers of drywall might do. Sounds heavy. I'd probably consider a light wooden frame and the sides made out of a double layer of cork. This would not be a load bearing box, just something that could be placed over the computer.

You would want airflow (the trade-off is classically sound versus temperature.) with a means for air to come out. Perhaps a low blowing case fan? :->

I think I could build something like that for much less than the sound reduction boxes I see online.

Hmm, too late at night - but I wanted to capture the thoughts on the noise reduction box!