And that is how we make a totally silent PC!
But we're not done yet. You wouldn't just take my word that it works, right? -
Well, how about some temperature and load graphs?
Here we have the system playing back a 1080p h.264 encoded avi from the SDD. This requires a lot more processing power than playing back from a Blu-ray drive. After an hour of playback the temperatures level out at about 45/46 deg C for the CPU cores and 52 deg C for the motherboard temperature sensor (wherever it is).
Next, an experiment was tried to lower the stock speed and voltages down to an acceptable level to show that you don't need the full 2.5GHz to playback a movie. The voltages were dropped to 0.925 for the vcore and the CPU speed taken down to 2GHz.
Playing back a Blu-ray disc shows that the CPU cores drop to about 40/41 deg C and the motherboard drops to 50 deg C after an hour of disc playback; nice and cool.
But if running things below stock speed doesn't tickle your fancy, then we reset the voltages and core speed to defaults and play the movie again. This time CPU temperatures jumped by 10 deg C up to 50/51 and the motherboard sensor (still no idea where it is) up around 58 deg C.
What can we take home from this? Well, under-clocking and under-volting can result in significant temperature drops, so long as you have the performance excess to handle the core requirements of the system. In our case playing back HD videos was easily achievable with a 2GHz core speed.
The downside to a system like this really comes around to the size of the case required and the size of the heatsink inside of it. There are a number of other options available out there with specialist case manufacturers attaching heat pipes directly to the side of their thick walled and finned aluminium cases.
The bottom line is really down to how much you want to spend and how quiet you are willing to tolerate. Today has proven that it doesn't cost the world to make a system that is totally silent, so long as you don't mind a slightly larger case.
Don't be afraid to experiment with under-volting, too. There is rarely any damage to be done to a processor by reducing its voltage. You might be surprised what you can get those left over bits of technology to do when you play around with them.