background image

Introduction

3

Introduction

This article highlights performance improvements available when you use HP’s TCP Segmen-

tation Offload (TSO) capabilities in conjunction with the new A7011A and A7012A 2-port 

Gigabit Ethernet cards (Figure 1) in a powerful server such as the HP rp4440.
TSO works especially well in networks sending large amounts of data, such as in: web serv-

ing applications, data backups, or file transfer applications including NFS. TSO reduces 

CPU load thereby improving overall system response. Greater than 50% reduction in CPU 
utilization has been observed on some FTP workloads.

1

Figure 1

HP PCI-X 2-Port Gigabit Ethernet Card (A7012A shown)

1. Not all applications benefit from TSO. Only data-intensive applications that transmit large data 

buffers using TCP over IPv4 are improved. Other types of applications will not significantly 
benefit from TSO. Performance improvements vary depending upon the hardware and software 
used. For details on recommended configurations, please refer to the section in this paper called 
“Technology Combinations to Use or to Be Aware Of.”

Summary of Contents for rp4440

Page 1: ...ights 8 Suggested Use 8 Achieving High Availability with 2 Port Cards 8 Technology Combinations to Use or to Be Aware Of 9 Test Details 10 Products Used in Testing 10 Test Configuration 11 For More Information 11 Taking the Next Step 11 Legal Notices 12 TCP Segmentation Offload TSO Performance On HP rp4440 Servers Using PCI X 2 Port Gigabit Ethernet Cards ...

Page 2: ......

Page 3: ...NFS TSO reduces CPU load thereby improving overall system response Greater than 50 reduction in CPU utilization has been observed on some FTP workloads 1 Figure 1 HP PCI X 2 Port Gigabit Ethernet Card A7012A shown 1 Not all applications benefit from TSO Only data intensive applications that transmit large data buffers using TCP over IPv4 are improved Other types of applications will not significan...

Page 4: ...bled The Gigabit Ethernet cards tested with TSO for this paper are the PCI X 2 port A7011A card with fiber based connectors and the A7012A card with copper based connectors The 2 port cards provide the following benefits Higher port density for I O slot constrained systems Higher levels of failover protection because two cards have no single point of failure The same level of failover protection w...

Page 5: ...g for optimal application performance These measurements can help determine how well one or a series of batch programs will run with a certain workload or how many user requests can be handled The performance gains in service demand and throughput shown in this article were measured with the netperf benchmarking software The following charts show the overall performance of one two and four ports o...

Page 6: ...Demand savings are for 1 port with TSO on 47 less Service Demand for 2 ports with TSO on 47 less Service Demand and for 4 ports 46 less Service Demand than when TSO is off For bidirectional traffic TSO reduces Service Demand an average of 27 The actual Service Demand savings are for 1 port with TSO on 24 less Service Demand for 2 ports with TSO on 30 less Service Demand and for 4 ports 26 less Ser...

Page 7: ...throughput increases are for 1 port with TSO on 3 95 Mbit s more throughput for 2 ports with TSO on 178 63 Mbit s more throughput and for 4 ports 577 18 Mbit s more throughput than when TSO is off TSO does not significantly affect transmit only throughput because the ports are already at link rate TSO increases the throughput of bidirectional traffic on iether based GigE cards especially over mult...

Page 8: ...E The following recommendations assume that your systems are also configured with failover software such as HP Serviceguard and Logical Volume Manager Consult http docs hp com for full details on configuring your products for high availability Connect each GigE port through a different network switch and ensure that the switches are bridged to the same IP subnet Failover between the two network pa...

Page 9: ...ow a significant improvement in service demand but a decrease in per card throughput The possible reduction in throughput on igelan based cards ranges from 2 on smaller systems to 11 on larger systems In this situation systems with hardware partitioning would experience the greatest throughput decrease The 2 port GigE cards supported by the iether driver include the A7011A and A7012A 2 port PCI X ...

Page 10: ...either the IEtherEnh 00 or GigEtherEnh 01 drivers to enable TSO functionality Card Tested A7012A A7011A 2 port Gigabit Ethernet card PCI X 64 bit 133MHz LAN Driver version IEtherEnh 00 B 11 11 11 Clients generating the test load for Gigabit Ethernet Eight rx2600 servers Two 1 5 GHz Intel Itanium2 CPUs each Operating System HP UX 11i version 2 B 11 23 0303 4 One A6825A PCI 1000Base T card per rx260...

Page 11: ...ease go to http www hp com products1 unixserverconnectivity This paper is the latest in a series of white papers detailing the performance of HP s link and server products For a complete list of white papers on HP s networking and I O products including Gigabit Ethernet and TSO solutions go to http docs hp com Taking the Next Step If you would like to try the TSO product you can obtain an HP UX 11...

Page 12: ...companying such products and services Nothing herein should be construed as constituting an additional warranty HP shall not be liable for technical or editorial errors or omissions contained herein HP UX Serviceguard and Superdome are registered trademarks of the Hewlett Packard Corporation PCI X is a registered trademark of the PCI SIG All other trademarks and registered trademarks are the prope...

Reviews: