Hello,

here are some differences

WS-X6148-GE-TX:

Forwarding architecture: These modules provide centralized Cisco Express Forwarding.

• Forwarding performance: These modules forward packets up to 15 Mpps per system.

• Fabric connection: These modules provide a 32-Gbps shared bus connection.

• Supervisor engine: These modules work with Supervisor Engine 1A, Supervisor Engine 2, Supervisor 32, or Supervisor Engine 720.

• Distributed forwarding upgrade: No upgrade is available; classic interface modules cannot be upgraded for distributed forwarding.

• Slot requirements: These modules can occupy any slot in any Cisco Catalyst 6500 Series chassis.

• Maximum port density per chassis: These modules support up to 1152 10/100 ports or 576 10/100/1000 ports in the Cisco Catalyst 6513 chassis; up to 768 10/100 ports or 384 10/100/1000 ports in the Cisco Catalyst 6509 chassis; up to 480 10/100 ports or 240 10/100/1000 ports in the Cisco Catalyst 6506 chassis; and up to 192 10/100 ports or 96 10/100/1000 ports in the small-form-factor Cisco Catalyst 6503 chassis.

• Field-installable and -upgradable inline-power daughter cards: These modules help enable centralized power distribution to IP phones, wireless access points, and other devices by sharing the same Category 5 UTP cabling used for network connections

WS-X6548-GE-TX:

• Forwarding architecture: These modules use the central Cisco Express Forwarding engine located on the supervisor engine.

• Forwarding performance: These modules forward packets up to 30 Mpps per system and up to 15 Mpps per slot if upgraded to support distributed forwarding.

• Fabric connection: These modules connect to the switch fabric through one 8-Gbps connection and the 32-Gbps shared bus.

• Supervisor engine: These modules work with Supervisor Engine 1A, Supervisor Engine 2, or Supervisor Engine 720.

• Slot requirements: These modules can occupy any slot in any Cisco Catalyst 6500 Series chassis.

• Maximum port density per chassis (48-port modules): These modules support up to 576 ports per Cisco Catalyst 6513, and up to 384 ports per Cisco Catalyst 6509.

• Maximum port density per chassis (16-port modules): These modules support up to 192 ports per Cisco Catalyst 6513, and up to 128 ports per Cisco Catalyst 6509.

please check here

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/product_data_sheet0900aecd8017376e.html

and

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/product_data_sheet0900aecd8017376e_ps4835_Products_Data_Sheet.html

HIH

serg