With the upcoming OpenSolaris 2009.06 release, how does networking perform on Intel Nehalem servers vs. Linux? One of the network performance questions asked by customers is "Can a system achieve X Gbit/s?" or "Can a system send/receive y packets/sec?" after they have characterized the workload and find that networking may be the limiting factor. I’ll take a look at out of box performance using a micro-benchmark tool uperf that shows the server’s capabilities.
Intel Nehalem servers have sufficient cpu cycles and I/O bandwidth to drive one 10GbE port at line rate for large packet sizes. To see a meaningful difference between Solaris and Linux, I chose a four port configuration that can show difference in throughput. When PCIe gen. 2 10 Gigabit Ethernet is widely available, the four ports can come from two NIC and take only two PCIe slots. Since I use PCIe gen. 1 10 Gigabit Ethernet, the four ports come from four NIC to avoid PCIe bandwidth becoming the bottleneck.
SUSE Linux Enterprise 11 is chosen as SUSE is widely used and it is based on a more recent Linux kernel than latest Red Hat distro. Compared to SLES 10 or RHEL 5.3, SLES 11 includes TX multiqueue support. This helps TX scales better with more connections. For simplicity, no tuning is done for etiher Linux or OpenSolaris. Tuning Linux will improve some results.
S10 Update 7 throughput drops significantly with more connections because of high rate of interrupts. Tuning to interrupt more cpu:
/etc/system set ddi_msix_alloc_limit=4 set pcplusmp:apic_intr_policy=1 set pcplusmp:apic_msix_max=4 set pcplusmp:apic_multi_msi_max=4 /kernel/drv/ixgbe.conf rx_queue_number=8;
improves performance to be more in line with OpenSolaris. TCP RX throughput more than doubles to 20.6 Gbit/s, and TCP TX throughput is 26.6 Gbit/s at 1000 connections.
uperf uses XML to describe the workload. The profile that describes TCP TX throughput is here. The profile that describes TCP RX throughput is here. The profiles are written based on four clients; if different number of clients are used, modify the number of groups to match the number of clients.
- SUT: Sun Fire X4270, dual socket Intel Nehalem @ 2.66 GHz. Hyper-threading is on (i.e. change BIOS default). 24 GB of memory.
- OS: OpenSolaris 2009.06; Solaris 5/09; SUSE Linux Enterprise 11 (188.8.131.52-5 kernel)
- Four X1106A-Z Sun 10 GbE with Intel 82598EB 10 GbE Controller installed on SUT. ixgbe driver version 184.108.40.206-NAPI compiled on SUSE 11.
- Clients: Four Sun Fire X4150, dual socket Intel Xeon @ 3.16 GHZ, 8 GB main memory. Three of the X4150 runs Solaris Nevada 109 with Sun Multithreaded 10 GbE Networking Card. One X4150 runs SUSE 10 SP2 with X1106A-Z Sun 10 GbE with Intel 82598EB 10 GbE Controller. Each 10 GbE port is connected back-back with one 10GbE port on SUT.
- set ddi_msix_alloc_limit=8
- soft-lso-enable = 1;
Tuning for Solaris clients: