I am planning on add a second DNS-323 with the new 2T Western Digital drives but wanted to make sure they are compatible first...
Here is the information about the drives....
Western Digital 2TB Caviar Green WD20EADS - SATA 3 Gb/s, 32MB Cache
As hard drive capacities increase, the power required to run those drives increases as well. WD Caviar Green drives make it possible for energy-conscious customers to build systems with higher capacities and the right balance of system performance, ensured reliability, and energy conservation.
Reduced power consumption - WD has reduced power consumption by up to 40 percent compared to standard desktop drives with the combination of WD's IntelliSeek™, NoTouch™, and IntelliPower™ technologies.
Helps enable eco-friendly PCs - WD Caviar Green drives yield an average drive power savings of 4-5 watts over standard desktop drives making it possible for our energy-conscious customers to build systems with higher capacities and the right balance of system performance, ensured reliability, and energy conservation.
 
 
Specifications 
 
   Drive Type:   Internal 
  
 
   Capacity (GB):   2000 
  
 
   Interface:   SATA 3.0Gb/s 
  
 
   Interface Type:   SATA 
  
 
   Spindle Speed (RPM):   Intellipower 
  
 
   Buffer Memory:   32MB 
  
 
   Data Transfer Rate on Serial ATA:   Up to 3000 Mb/sec 
  
 
   Form Factor:   3.5" 
  
 
   Temperature, Operating (°C):   0 to 60 
  
 
   Temperature, Nonoperating (°C):   -40 to 70 
  
 
   Shock, Operating: 2 msec (Gs):   30 
  
 
   Acoustics Idle (bels—sound power):   24 dBA 
  
 
   Acoustics Seek (bels—sound power):   25 dBA 
  
 
   Acoustics Performance Seek (bels—sound power):   29 dBA 
  
 
   Dimensions:   1.03" x 4.0" x 5.8"