tailieunhanh - Networking: A Beginner’s Guide Fifth Edition- P40

Networking: A Beginner’s Guide Fifth Edition- P40:I have run into many people over the years who have gained good even impressive working knowledge of PCs, operating systems, applications, and common problems and solutions. Many of these people are wizards with desktop computers. | Chapter 13 Network Servers Everything You Wanted to Know but Were Afraid to Ask 177 NOTE These days some processors have multiple processor cores on the same chip. The values given for the number of allowed Windows server processors are for the number of processor chips in other words the sockets on the motherboard . If you plan to use UNIX then it depends some versions of UNIX support multiple processors others do not. Another factor to consider is the job that the server does and whether the server s tasks are presently bottlenecked by the processor. File and print servers may not need multiple processors. While they benefit from fast processors the advantage is not as great as you might think. It s far more important for a file and a print server to have a lot of random access memory RAM and a fast disk subsystem. Database servers on the other hand are processor-hungry and definitely benefit from as many processors as possible running at the fastest possible speed. It s also important for the database server software to be configured in such a way that it can make optimal use of multiple processors. Web servers tend to be modest in their processor requirements they rely on fast buses fast network connections a lot of RAM fast disks and that s about it. A fast processor or multiple processors is nice on most web servers but it also might be overkill. Managing multiple processors requires a lot of overhead work on the part of the operating system. Because of this having twice as many processors in a computer doesn t double its processing capability instead doubling the processors might improve the computer s speed by only about 50 percent. Depending on your operating system there is also a point of diminishing returns past which additional processors won t give you much additional performance. Part of this has to do with how the operating system handles multiple processors. Another part has to do with the number of threads doing work in the operating system. .