Abstract

Dell Computer Corp. commissioned The Tolly Group to benchmark two LAN switches. This Tolly Group performance evaluation examines two Dell Ethernet switches tested in September 2001: the Dell PowerConnect 3024, a managed workgroup switch with 24 Fast Ethernet ports and two Gigabit Ethernet uplinks, and the Dell PowerConnect 5012, a Gigabit Ethernet aggregation switch with ten 10/100/1000Base-T copper ports and two Gigabit fiber ports. The report focuses on a core requirement for switch buyers: the ability to sustain zero frame loss while forwarding line-rate, bidirectional Layer 2 traffic across all ports and across a range of packet sizes. 

Tolly’s results show that both switches achieved full-duplex, zero-loss wire-speed throughput at all tested frame sizes: 64, 512, and 1,518 bytes. In full-mesh, full-duplex testing, the PowerConnect 3024 delivered 12.8Gbit/s aggregate throughput, while the PowerConnect 5012 delivered 24Gbit/s aggregate throughput. In each case, measured forwarding performance matched the theoretical maximum and the vendors’ advertised capacity, representing 100% of theoretical throughput and 100% of advertised throughput for every tested frame size. The table on page 2 reports frame-rate results of 19,047,583fps, 3,007,504fps, and 1,040,309fps for the 3024, and 35,714,286fps, 5,639,098fps, and 1,950,585fps for the 5012. 

The report also tested IEEE 802.3ad link aggregation and found that both platforms maintained 100% of theoretical maximum throughput with aggregation enabled. In the PowerConnect 3024 aggregation scenario, two switches were linked through a four-port Gigabit fiber trunk while sustaining 8Gbit/s aggregate throughput across 20 Fast Ethernet ports. Tolly concluded that these switches could expand bandwidth incrementally without degrading performance. 

Test methodology used Spirent SmartBits 2000 and 6000 systems with SmartFlow 1.3 to generate steady-state, full-mesh, full-duplex traffic, with three iterations of each one-minute test and a zero-loss threshold of 0.001%. Both switches were tested with software version 5.1.4. Beyond raw throughput, the report notes support for features such as 802.1Q VLANs, 802.1p Class of Service, IGMP snooping, SNMP and Telnet management, port mirroring, Spanning Tree, and up to 8,000 MAC addresses.