HP Rp7410 PCI Gigabit Ethernet Performance Paper using HP Server rp7410 - Page 9

Percent of CPUs Used cpu utilization 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% xmit recv bd Gigabit Ethernet Performance in rp7410 Servers CPU Utilization on 8-Way rp7410 for Gigabit Ethernet 1 12.82% 28.17% 38.91% 2 26.90% 45.13% 68.76% Num ber of Cards 4 63.96% 91.16% 99.87% This chart shows the total amount of CPU utilization for 1, 2, and 4 Gigabit Ethernet cards in an 8-way rp7410. With two NICs running at link rate with receive only traffic, the rp7410 still had approximately 55% of its CPU cycles available for other applications. When supporting two NICs with transmit only traffic running at link rate, the rp7410 had over 73% of its CPU capacity available for other applications. A total of four Gigabit Ethernet NICs can be operated at full link rate carrying unidirectional data without driving the CPU utilization to the limits of its capacity. With two NICs running at link rate and carrying bi-directional traffic, the rp7410 had over 31% of its CPU cycles available for other applications. As illustrated in the above chart, when four NICs are carrying bi-directional traffic the CPU utilization is very close to 100%. This indicates that the rp7410 is reaching the limit of its CPU capacity. Bi-directional traffic consumes more of the system's resources than either transmit-only or receive-only traffic. Therefore, as the total volume of bi-directional traffic increases, the demand on system resources increases faster than it does for unidirectional traffic. This increasing load on the CPUs causes the limiting of bi-directional throughput as the number of cards increases, as shown on the previous chart. Page 7