10 GbE ports can be used with the Sun SPARC Enterprise T5120/T5220 servers by either plugging in a dual-port PCI-e Network Interface Unit (NIC) (X1027A-z) or using the on-chip dual 10GbE Network Interface Unit (NIU). To connect to the on-chip, use a PCI slot to hold the X (roman 10) Attachment Unit Interface (XAUI), which is a standard for connecting 10GbE devices.
There are important tuning parameters for both the NIU and PCI-e 10 GbE options. For example, the tunable parameter for the number of kernel threads that offload processing of received packets from interrupt CPU should be set in /etc/system:
Performance difference between these two methods are offered in a Sun blog:
- "NIU wins in all micro-benchmarks except one - single 10GbE port transmitting UDP small packets.
- Sun Multi-threaded 10GbE PCI-e NIC can transmit an impressive 2.1 million 64 byte UDP packets per second, 50% more than NIU (1.4 million pps) out of one port, due to the fact that it has 50% more transmit DMA channels than NIU (12 vs. 8 per port)."
If sending small UDP packets is most of the workload, a higher packet rate may be delivered by Sun Multi-threaded 10GbE PCI-e NIC. Otherwise, NIU offers higher throughput or lower CPU utilization at similar throughput.
"On 2 10GbE port throughput test, 2 NIU can achieve an impressive 14.6 Gbits/s on TCP transmit, or 18.2 Gbits/s on TCP receive using 8Kbytes messages and 145 connections," the blog states. "For TCP transmit, the CPU efficiency (measured by Gbps/GHz) of NIU is 23% higher than PCI-e NIC at maximum throughput for 2 ports, and 46% higher at maximum throughput for 1 port."
For specific performance features on both the NIU and PCI-E 10GbE NIC, how to tune the on-chip 10GbE (NIU) and Sun Multi-threaded 10GbE PCI-E NIC on T5120/T5220 and more, see Pure See\'s weblog.
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