IBM eX5 Implementation Guide

Chapter 3. IBM System x3850 X5 and x3950 X5 113

Figure 3-30 Cooling zones in the x3850 X5

Six strategically located hot-swap/redundant fans, combined with efficient airflow paths,

provide highly effective system cooling for the eX5 systems. This technology is known as IBM

Calibrated Vectored Cooling™ technology. The fans are arranged to cool three separate

zones, with one pair of redundant fans per zone.

The fans automatically adjust speeds in response to changing thermal requirements,

depending on the zone, redundancy, and internal temperatures. When the temperature inside

the server increases, the fans speed up to maintain the proper ambient temperature. When

the temperature returns to a normal operating level, the fans return to their default speed.

All x3850 X5 system fans are hot-swappable, except for Fan 3 in the bottom x3850 X5 of a

2-node complex, when QPI cables directly link the two servers.

3.14.2 MAX5 power supplies and fans

The MAX5 power subsystem consists of one or two hot-pluggable 675W power supplies. The

power subsystem is designed for N+N (fully redundant) operation and hot-swap replacement.

Standard models of MAX5 have one power supply installed in power supply bay 1. For

redundancy, install the second power supply that is listed in Table 3-35.

Table 3-35 Ordering information for the IBM MAX5 for System x

A fan that is located inside each power supply cools the power modules.

MAX5 has five redundant hot-swap fans, which are all in one cooling zone. The IMM of the

attached host controls the MAX5 fan speed, based on altitude and ambient temperature.

Fans also respond to certain conditions and come up to speed accordingly:

򐂰 If a fan fails, the remaining fans ramp up to full speed.

򐂰 As the internal temperature rises, all fans ramp to full speed.

Part number Feature code Description

60Y0332 4782 IBM 675W HE Redundant Power Supply