I don’t have any hard dB measurements (no meter), but I’m guessing it was in the 60-ish dB range. You could have a nice quiet conversation next to the server, but it’s still audible from across the room.

My only word of warning is this: The R905 (and I’m pretty sure it’s the same for the R900) consumes about 500W of power at idle with a decent amount of RAM and disks. Power is pretty expensive where I am, so it ended up not making economic sense to keep running the server. I got an older T710 with 2xE5620 CPUs and 96GB RAM to replace it — that hardware cost more than twice the price of the R905, but the performance is probably better (even with half the CPUs) — and it uses about 200W. For me the more expensive server pays for itself in about 18 months due to energy savings. Plus the T710 is also just a bit louder than an average desktop machine.

Also, I believe the R900 has a different fan setup than the R905, so your results on the sound issue might differ.

Being I’m soon going to buy a Dell R900 I sure would like to know what the db’s level was after you replaced the fans. I have seen spec’s on the stock fans and the db’s are 70. Just wonder what your project turned out to be.

Thanks