Throughput Test; Latency Measurements; Power Consumption Measurements; Table 8: 6600 Series Power Consumption Measurements - HP ProCurve 6600 Switch Series Technical Overview

In the unlikely case where the average packet size is consistently smaller, the throughput will be less than wire
speed . For example, consider a worst-case scenario, where the average packet size is 64 bytes . This would
result in a throughput of approximately 70% to 80% of the rated wire-speed capacity . HP networking considers
such minimum-sized packet-traffic scenarios being realized over an extended period of time to be extremely
atypical and unlikely to be experienced by customers in the field .
Note: The limits described here do not apply to Gigabit ports .

Throughput test

A fully meshed performance test sends packets from each port to every other port during the test . This type
of test exercises both the modules and the backplane . These tests show the ProCurve 6600 Switch Series to
achieve wire speed on all ports simultaneously .

Latency measurements

Latency is commonly measured as the amount of time it takes for a byte inside a packet to enter and then leave
the switch . Latency statistics typically are documented as including both the processing time of the switch as it
makes its forwarding decision, and the time for the packet itself to enter and leave the switch . In Table 7, this
definition of latency corresponds to the FIFO latency statistics . The LIFO latency statistics that are also listed in
the table represent only the packet transmission time .
Almost all switches currently on the market are store and forward, so the entire packet is received into the
switch before the switch begins to transmit the packet out the egress port . Including the packet receive time
in the FIFO latency statistics is appropriate, because this extra time is a contributing component of the overall
transit time of the packet as it moves through the network .
The latency figures for the ProCurve 6600 Switch Series are consistently low . Latencies this low will not be a
factor in general network operation, even with streaming video or VoIP applications . The LIFO latency values
are fairly consistent across all packet sizes because ingress and egress packet processors operate on the
header of the frame (not the whole frame), while the full frame is buffered in and out of packet buffer memory .
Memory transfers are scheduled to fit a full 1518-byte frame, so frames are transferred in and out of memory in
approximately the same amount of time, regardless of packet size . While the frame headers are being looked
up, and actions required for the frame on egress are being coordinated among interface modules, the frame is
transferred through the switching fabric module .

Power consumption measurements

Table 8 details the expected power consumption on the various 6600 series switches with one and two power
supply unit (PSU) configurations .
6600-24G
1 PSU configuration
Idle power 93 W
Max . power 125 W
Max . heat dissipation 425 Btu/hr
2 PSU configuration
Idle power 129 W
Max . power 160 W
Max . heat dissipation 545 Btu/hr
Note: Maximum power includes all ports connected and forwarding data at 100% utilization. Idle power was measured with all ports connected but not
forwarding data.

Table 8: 6600 series power consumption measurements

6600-24G-4XG 6600-48G
127 W 144 W
172 W 175 W
587 Btu/hr 597 Btu/hr
168 W 180 W
204 W 209 W
697 Btu/hr 713 Btu/hr
6600-48G-4XG 6600-24XG
191 W 310 W
227 W 372 W
774 Btu/hr 1267 Btu/hr
226 W 345 W
261 W 405 W
890 Btu/hr 1382 Btu/hr
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