System information

Chapter 1. Introduction to IBM eServer BladeCenter technology and its advantages 19
twice the current density of a non-blade server. The IBM Eserver BladeCenter supports a
minimum of one 4 port 1 GB Ethernet switch for up to fourteen blade servers. A total of four
switch modules can be utilized within the IBM Eserver BladeCenter. This can be a
combination of either Fiber Channel or Ethernet.
We recommend the use of blade servers for the following situations:
򐂰 Space constrained environments
򐂰 WebSphere
򐂰 Linux clusters
򐂰 Web caching
򐂰 Collaboration applications (Lotus Notes®, Microsoft Exchange and Citrix)
򐂰 Dynamic Web serving - Load balancing
򐂰 Firewall
򐂰 Telecommunications
򐂰 Active directory services
򐂰 Scientific and technical computing
These applications are typically processor and memory intensive, and so lend themselves to
the scale out option rather then the scale up option. The scale out option is where the
strength of the IBM Eserver BladeCenter becomes obvious. Due to the highly scalable
range of components available with the BladeCenter unit, the blade server has a huge
market.
Figure 1-13 Scale up versus scale out
Attractive cost savings are also possible where a large number of rack installed servers are
required. These savings run from power usage, to hardware procurement (due to not
duplicating components), through to server management. Table 1-1 on page 20
demonstrates the input voltage required for different servers providing the same number of