Adapter performance guidelines
TheAIX® operating system provides a number of guidelines to maximize adapter performance.
User payload data rates can be obtained by sockets-based programs for applications that are streaming data over a TCP connection. For example, one program send( ) calls and the receiver recv( ) calls. The rates are a function of the network bit rate, Media Transmission Unit (MTU) size (frame size), physical level overhead such as the inter-frame gap and preamble bits, DataLink headers, and TCP/IP headers and a Gigahertz speed processor. These rates are best case numbers for a single LAN, and can be lower if going through routers or additional network hops or remote links.
Single direction (simplex) TCP streaming rates are rates that can be seen by a workload like FTP sending data from system A to system B in a memory-to-memory test. See the ftp command. Full duplex media functions better than half duplex media because the TCP acknowledgements can flow back without contending for the same wire that the data packets are flowing on.
Network type | Raw bit rate (Mbits) | Payload rate (Mb) | Payload rate (MB) |
---|---|---|---|
10 Mb Ethernet, Half Duplex | 10 | 6 | 0.7 |
10 Mb Ethernet, Full Duplex | 10 (20 Mb full duplex) | 9.48 | 1.13 |
100 Mb Ethernet, Half Duplex | 100 | 62 | 7.3 |
100 Mb Ethernet, Full Duplex | 100 (200 Mb full duplex) | 94.8 | 11.3 |
1000 Mb Ethernet, Full Duplex, MTU 1500 | 1000 (2000 Mb full duplex) | 948 | 113.0 |
1000 Mb Ethernet, Full Duplex, MTU 9000 | 1000 (2000 Mb full duplex) | 989 | 117.9 |
10 Gb Ethernet, Full Duplex, MTU 1500 (with RFC1323 enabled) | 10000 | 7200 (peak 9415)1 | 858 (peak 1122)1 |
10 Gb Ethernet, Full Duplex, MTU 9000 (with RFC1323 enabled) | 10000 | 9631 (peak 9891)1 | 1148 (peak 1179)1 |
FDDI, MTU 4352 (default) | 100 | 92 | 11.0 |
Asynchronous Transfer Mode (ATM) 155, MTU 1500 | 155 | 125 | 14.9 |
ATM 155, MTU 9180 (default) | 155 | 133 | 15.9 |
ATM 622, MTU 1500 | 622 | 364 | 43.4 |
ATM 622, MTU 9180 (default) | 622 | 534 | 63.6 |
Network type | Raw bit rate (Mbits) | Payload rate (Mb) | Payload rate (MB) |
---|---|---|---|
10 Mb Ethernet, Half Duplex | 10 | 5.8 | 0.7 |
10 Mb Ethernet, Full Duplex | 10 (20 Mb full duplex) | 18 | 2.2 |
100 Mb Ethernet, Half Duplex | 100 | 58 | 7.0 |
100 Mb Ethernet, Full Duplex | 100 (200 Mb full duplex) | 177 | 21.1 |
1000 Mb Ethernet, Full Duplex, MTU 1500 | 1000 (2000 Mb full duplex) | 1811 (1667 peak) 1 | 215 (222 peak) 1 |
1000 Mb Ethernet, Full Duplex, MTU 9000 | 1000 (2000 Mb full duplex) | 1936 (1938 peak) 1 | 231 (231 peak) 1 |
10 Gb Ethernet, Full Duplex, MTU 1500 | 10000 (20000 Mb full duplex) | 14400 (18448 peak) 1 | 1716 (2200 peak) 1 |
10 Gb Ethernet, Full Duplex, MTU 9000 | 10000 (20000 Mb full duplex) | 18000 (19555 peak) 1 | 2162 (2331 peak) 1 |
FDDI, MTU 4352 (default) | 100 | 97 | 11.6 |
ATM 155, MTU 1500 | 155 (310 Mb full duplex) | 180 | 21.5 |
ATM 155, MTU 9180 (default) | 155 (310 Mb full duplex) | 236 | 28.2 |
ATM 622, MTU 1500 | 622 (1244 Mb full duplex) | 476 | 56.7 |
ATM 622, MTU 9180 (default) | 622 (1244 Mb full duplex) | 884 | 105 |
- Peak numbers represent best-case throughput with multiple TCP sessions that are running in each direction. Other rates are for single TCP sessions. The single session rates vary based on the processor frequency, specific adapter, and PCI slot type that are used.
- 1000 Mbit Ethernet (Gigabit Ethernet) duplex rates are for PCI-eXtended (PCI-X) adapters or peripheral component interconnect express (PCIe) adapter slots. Performance is slower on duplex workloads for PCI adapters or PCI-X adapters in PCI slots. The 10 Gb Ethernet rates that are specified are only for PCIe adapters.
- Data rates are for TCP/IP that uses the internet protocol version
4 (IPv4). The RFC1323 option is enabled for the following
adapters:
- Adapters with an MTU size of 4096 and larger
- 10 Gigabit Ethernet or faster adapters
- Payload rate (Mb) column is in units of megabits per second, where 1 Mb is 1,000,000 bits. Payload rate (MB) column is in units of megabytes per second, where 1 MB is 1,048,576 bytes.