HP Server rp4440 TCP Segmentation Offload (TSO) Performance On HP rp4440 Serve - Page 7

Throughput: Faster = Better Throughput: Faster = Better Figure 3 rp4440 Throughput with GigE and TSO Figure 3 shows transmit and bidirectional throughput results on the rp4440 over GigE both without and with TSO. In the enclosed graph, the Gigabit Ethernet throughput numbers are shown in Megabits per second. In this test, the higher the throughput number, the better! • For bidirectional traffic, TSO increases throughput much more with multiple ports. The actual throughput increases are: for 1 port with TSO on, 3.95 Mbit/s more throughput , for 2-ports with TSO on, 178.63 Mbit/s more throughput , and for 4 ports, 577.18 Mbit/s more throughput than when TSO is off! • TSO does not significantly affect transmit only throughput because the ports are already at link rate. TSO increases the throughput of bidirectional traffic on iether-based GigE cards especially over multiple ports. TSO does not improve throughput on systems that are already nearing link rate. But, because TSO does free up CPU, it can provide improved throughput for systems that are CPU-bound or that are not already at or near link rate on all network ports. 7