Stratus ftServer 4500 - CPU-I⁄O Enclosures: Front

System Design
Overview of ftServer 2600, 4500, and 6300 Systems 1-3
The following subsections provide more system design information.
• “CPU-I⁄O Enclosures: Front” on page 1-3
• “CPU-I/O Enclosures: Rear” on page 1-5
• “Description of System Components” on page 1-8
• “Peripheral Components” on page 1-10
CPU-I⁄O Enclosures: Front
Each ftServer 2600, 4500, or 6300 system comprises a minimum of two
CPU- I ⁄ Oenclosures
. Each CPU- I ⁄ O enclosure contains a CPU element and an
I/O element joined to the same board. The elements are numbered as follows:
• Upper enclosure: CPU element - 0 and I/O element - 10
• Lower enclosure: CPU element - 1 and I/O element - 11
Figure 1-2 shows a front view of the two CPU- I ⁄ O enclosures in a system, without the
bezel installed.
Both CPU-I/O enclosures are powered by a single power button (number 10 in
Figure 1-2) that is located on the bottom of the system front panel.
One of the I/O elements is the
primary (or active ) I/O element, while the other is the
secondary I/O element. The primary I/O element drives control of the video, USB ports,
COM ports, DVD drive, and modem (if attached). The PRIMARY system LED (see
Figure 3-2 and Table 3-2) indicates which CPU-I/O enclosure contains the primary I/O
element. (The primary CPU element may reside in the same CPU-I/O enclosure as the
primary I/O element, or it may reside in the other CPU-I/O enclosure.)
NOTE
For the sake of simplicity, this manual uses the term
primary (or active ) enclosure in some cases to indicate
the CPU-I/O enclosure in which the primary I/O element
resides.