Quiet computer

[David King]

>>> You might wants to consider using a low-power 'brick'-type AC->DC
>>> PSU (~90W?) and a DC-DC voltage converter that plugs directly into
>>> a mainboard's power connector. This will be quite noiseless.
>> Do you have any recommendations? Ideally it would mount on the case
>> (<http://www.logicsupply.com/product_info.php/products_id/134>) like
>> the current power supply does but I'm open to other options
> something like this (random example):
> http://www.logicsupply.com/product_info.php/products_id/596

The only types of power supplies with which I'm familiar are the ones  
that typically ship with most cases, so I'm a little confused by  
this, excuse my obvious ignorance :)

What does the DC-DC converter do, if the AC-DC converter supplies DC  
power?

What would be an example of this AC-DC converter? Could it power two  
3.5" hard drives in addition to the motherboard? How does it differ  
from a regular power supply?