Choose Form Factor

Chassis Type	Chassis Image	3.5"-Drives Chassis	2.5"-Drives Chassis
1U		Build	Coming Soon!
2U		Build	Coming Soon!
3U		Not Available	Not Available
4U		Build	Coming Soon!
5U		Not Available	Build
Tower		Build	Not Available

How to Choose

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  Real estate available.

  For many server shoppers, the main constraint on the form factor of the server that they can buy is the real estate they have available. The real estate is simply the amount of space that one has on a server rack, measured in rack units (one rack unit, or "1U", is equal to 1.75 in). If real estate constraints are not a factor for you, then we recommend considering the other aspects of form factor selection (see below), as buying a server with a higher rack unit count can have many advantages. If, on the other hand, real estate is a limiting factor, then be sure to purchase the server(s) for the space you have available.

• 

  Hard drives required (with room to expand).

  The next important aspect to consider when choosing a form factor is the amount of storage space you will need now and in the future. This will depend on the functions that the server will perform, the software you are running, and the type and quantity of data you are storing on it. Since these factors vary greatly from customer to customer, we can not yet offer an online guide for how to determine the storage capacity that one needs. What is important for all customers, though, is to consider how the server will be used in the long run. A server's storage capacity can fill up very fast, so you want to be sure that you buy a server with enough room to add extra hard drives if you need them (see table above to determine the maximum storage capacity of each U). Even if you don't use those extra hard drive bays now, it's much more economical to buy a few more hard drives (if you need more storage capacity down the road) than a whole extra server because you ran out of drive bay space. If you have more specific questions about your storage requirements, please don't hesitate to contact us.

• 

  Number of expansion slots.

  Systems with a lower U count (in particular 1U and some 2U servers) may not have enough room for all of the expansion slots (PCI-E 2.0, and the older PCI-E 1.0 and PCI-X) that a motherboard allows. Those systems frequently require a riser card that will fit expansion cards horizontally rather than the typical vertical configuration (there is not enough room for the latter in those systems). Even then, they will allow only a limited number of expansion slots (see table above). Common expansion cards include RAID controllers, InfiniBand and other network adapters, Voice over IP (VoIP), video cards, and others. So, if you need to install multiple expansion cards, you should choose a form factor that will accomodate that requirement (probably a 2U or higher).

• 

  Noise tolerance.

  As a general rule, smaller U servers (1U and 2U) make more noise while running than larger U servers (3U and 4U). The larger servers can fit larger fans, which in turn spin at a slower pace and produce less noise. If you are shopping for a server for a large data center where operating noise is an accepted part of life, then this aspect should not be a major factor in your purchasing decision. If, on the other hand, you are shopping for a server that will stand on its own in a small company office, then take into consideration that a 1U (or even 2U) may sound too loud and whiny for that environment. All servers make operating noise, though - there's no way around it. But if you really must reduce the noise pollution in your office or server room, then get a higher U server which will have bigger fans.