Web Performance Tuning

Browser Speed

The web browser is probably not going to be your bottleneck simply because the average performance of a point-to-point TCP connection on the Internet is only about 50KByte per second,^[2] while most browsers are able to parse and display data faster than that. My own seat-of-the-pants benchmark is that Netscape 4 running on a 75MHz Pentium laptop under Linux 2.0 can parse a large HTML file from memory cache or from a 10Mbps LAN connection at a rate of about 80KB per second. On the other hand, Netscape 4 running on a Mac PowerBook 5300cs seems to achieve only about 4KB per second reading from memory cache or a LAN.

One might think that browsers would store cached documents in a parsed format for quicker subsequent display, but an examination of the cache shows that this is not the case. This raises the interesting possibility of pre-parsing HTML on the server and storing it in parsed format. There is no standard format for parsed HTML, so the performance gain would be at the expense of portability and human readability. In any case, it is unusual for the Internet to return enough data in HTTP replies to overwhelm the parsing capability of the browser. What this means for capacity planning is that performance is not currently a factor in choosing web browsers, although this may change as Internet infrastructure is upgraded.

In the outbound direction, web browsers do not need to make sustained HTTP requests any faster than a human can digest the replies. Web browsers are ...