Datasheet

Sun Microsystems, Inc.
Fans
Cooling fans in the Sun Fire X4100 M2 and X4200 M2 servers are positioned in two rows for redundancy just behind the front bezel.
They are hot swappable and each fan module has an LED fault indicator. The fans are accessible from the top hinged hatch door in
the front left side of the server, when facing the server from the front. This enables the fans to be accessed without interrupting sys-
tem operation. Additionally, it makes it possible to service fans by only partially removing the server from the rack, allowing all
cabling to remain in place.
Fan speed is modulated by the Service Processor with Pulse Width Modulation by an ADM 1026 sensor chip. All fans are controlled
with the same PWM frequency so they all operate at the same speed. The ADM 1026 device uses readings from 3 sensors to control
the fan speed: Front Panel Ambient Temperature, CPU 0 Die Temperature, CPU 1 Die Temperature. The Service Processor reads the
fan speeds and turns the fan fault LED on if the RPM is under a threshold.
The fan modules in Sun Fire X4100 M2 and X4200 M2 differ from each other. The layout, however, is very similar in both servers. In
the front of the motherboard compartment, beneath the hinged hatch door, there are 2 redundant rows of fan trays. Each row of fan
trays is occupied by 3 fan modules. In a Sun Fire X4100 M2 server, the fan modules are populated by pairs of 40 mm, 15,000 RPM
Delta TFB0412EHN fans. In a Sun Fire X4200 M2 server, the fan modules are populated by single 80 mm, 7,500 RPM Delta
FFB0812UHE fans. The Sun Fire X4100 M2 server contains a total of 12 cooling fans and the Sun Fire X4200 M2 server contains a total
of 6 cooling fans.
Figure 5-2: Sun Fire X4100 M2 Server Cooling Fan Layout
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