A REFERENCE GUIDE FOR OPTIMIZING DELL™ MD1000 SAS SOLUTIONS  VER A00 
PAGE 6    5/06/2005 
 
 
 
  Figure 2: Bandwidth improvement with SAS port aggregation 
 
 
 
 
 
 
 
 
Improved capacity scalability 
•  SAS allows for port expansion, enabling the ability to “daisy-chain” storage enclosures for 
dramatic improvements in capacity scalability. With Ultra320 SCSI, systems were limited to a 
maximum of 16 devices on a single SCSI channel. This typically translated to maximum of 14 
physical disks connected to a single SCSI channel on a RAID controller. With SAS expansion, 
a single SAS port can be expanded out to multiple SAS devices (similar to how Ethernet hubs 
can expand a single Ethernet connection into multiple devices). 
 
Other important changes to keep in mind about SAS: 
•  SAS continues to use the SCSI command sets for driver & software compatibility. 
•  SAS is not backwards compatible with Parallel SCSI. 
 
2.  Recommended Maintenance for your Dell PowerVault MD1000 SAS Solution 
Dell strives to provide the best possible customer experience for all of our enterprise server and 
storage products. Proper maintenance of your solution is essential to help ensure that the 
equipment remains in optimal working condition. Dell recommends the following suggested 
maintenance activities. 
Keep firmware/drivers/utilities up to date 
In general, Dell posts planned maintenance updates for firmware twice a year.  To stay current 
with the latest updates, customers can subscribe to Dell notification tools. Click the following link 
to sign up for technical updates.  
Up to 320MB/s 
Up to 12.0 Gbps performance