The Cisco stackable Catalyst 3750-X is enterprise-class wiring closet switches that facilitate the deployment of highly secure converged applications while maximizing investment protection for evolving network and application requirements. Combining 10/100/1000 and Power over Ethernet Plus (PoE+) or GE SFP configurations with four optional uplinks, the Cisco Catalyst 3750-X enhances worker productivity by enabling applications such as encryption, IP telephony, wireless, and video.

1. What's Your Take on the New Cisco 3750-X Switch with StackPower?
The Ciscostackable Catalyst3750-X is enterprise-class wiring closet switches that
facilitate the deployment of highly secure converged applications while maximizing
investment protection for evolving network and application requirements.
Combining 10/100/1000 and Power over Ethernet Plus (PoE+) or GE SFP
configurations with four optional uplinks, the Cisco Catalyst 3750-X enhances worker
productivity by enabling applications such as encryption, IP telephony, wireless, and
video.
The Cisco Catalyst 3750-X is built on the existing Cisco Catalyst 3750-ESeries.
The Cisco Catalyst X-Series switches build on the E-Series switches and add the
following features:
• Cisco StackPowertechnology, available only on the Cisco Catalyst 3750-X, manages
power very efficiently by aggregating and sharing power supplies across a stack of
switches. It also supports a feature known as Zero-Footprint RPS.
• Four field-replaceable network modules that provide 4 x 1 Gigabit and 2 x 10
Gigabit uplink interfaces for the switch.
• Full 802.3at PoE+ support provides 30W per port on all 48 ports in a single rack unit
(RU) switch.
• New LAN Base feature set offers comprehensive Layer 2 functionality.
• Dual redundant power supplies and fans: Four high-efficiency power supply options
are available, including a DC power supply for PoE applications. Two redundant,
field-replaceable fan modules are also included.
• MACsec provides hardware-based encryption (802.1ae) at line rate on all 48 ports
(requires IP Base). Includes MACsec Key Agreement (MKA) (included in Dot1X-rev).
• Open Shortest Path First (OSPF) for routed access in IP Base image.
Cisco 3750-X Model Comparison

2. All switch models can be configured with the optional four Gigabit Ethernet (GbE)
SFP or two 10GbE SFP+ uplink network modules.
New Cisco C3KX-NM-10G Network Module
Cisco also announced StackPower, a power-interconnect technology that brings
power resiliency to a stack of 3750-X switches. Cisco said a single 1,100-watt power
supply can provide power to four switches and the mission-critical endpoints
attached to them to help ensure business continuity.
New Cisco StackPower technology
StackPower technology creates a pool of power that shares a common load
consisting of all the switches in the power stack.
Cisco StackPower: One Power Pool, One Load

3. Up to nine switches can share power in a star topology by using an eXpandable
Power System (XPS).
Star Topology, Using an XPS

4. The switches below have been cabled up to form a power stack in order to make use
of unused power from switches with lower power requirements. This is the key
benefit of Cisco StackPower technology, flexible use of available resources.
Power Stack of Four Switches

5. Power sharing mode is the core of StackPower and is the simplest (see the below
diagram). The power gets allocated from the power pool as power requests come in
from the switches and PoE devices (IP phones, wireless access points, and so on).
Power Share Mode

6. Below, StackPower aggregates three power supplies on four switches (1100W +
1100W + 1100W + 0W = 3300W). The load requirement is 500W per switch (500W +
500W + 500W + 500W = 2000).
Power sharing among 4 Switches
Redundant mode (as shown below) reserves an amount of power for redundancy
from the power pool and guarantee operations in case of a single power supply
failure in the power stack.

7. Redundant mode
Should power requirements increase in any of the switches of the power
stack, StackPower will redirect power from the unallocated power pool to any port in
any switch in the stack.
Redundant power

8. More Cisco Catalyst Switch Tips:
Cisco Catalyst 3750-X: Redundant StackPower Cabling Information
Cisco 3750 Stacking Configuration
How to Select Power Supply for Catalyst 3750-X Series and Cisco 3560-X Switch?
Main Differences between Lines of Cisco 3750 Series Switches
Cisco Catalyst Access Switching