Editing TCP offload engine (section)

===Freed-up CPU cycles===
A generally accepted rule of thumb is that 1 Hertz of CPU processing is required to send or receive {{val|1|ul=bit/s}} of TCP/IP.<ref name="Foong">{{cite conference |author1=Annie P. Foong |author2=Thomas R. Huff |author3=Herbert H. Hum |author4=Jaidev P. Patwardhan |author5=Greg J. Regnier |date=2003-04-02 |title=TCP performance re-visited |conference=Proceedings of the International Symposium on Performance Analysis of Systems and Software (ISPASS) |location=Austin, Texas |url=http://www.nanogrids.org/jaidev/papers/ispass03.pdf}}</ref> For example, 5&nbsp;Gbit/s (625&nbsp;MB/s) of network traffic requires 5&nbsp;GHz of CPU processing. This implies that 2 entire cores of a 2.5&nbsp;GHz [[multi-core processor]] will be required to handle the TCP/IP processing associated with 5&nbsp;Gbit/s of TCP/IP traffic. Since Ethernet (10GE in this example) is bidirectional, it is possible to send and receive 10&nbsp;Gbit/s (for an aggregate throughput of 20&nbsp;Gbit/s). Using the 1&nbsp;Hz/(bit/s) rule this equates to eight 2.5&nbsp;GHz cores.

Many of the CPU cycles used for TCP/IP processing are ''freed-up'' by TCP/IP offload and may be used by the CPU (usually a [[Server (computing)|server]] CPU) to perform other tasks such as file system processing (in a file server) or indexing (in a backup media server). In other words, a server with TCP/IP offload can do more '''server''' work than a server without TCP/IP offload NICs.