Dell Precision 490 Desktop User's Guide - Page 22

Power Management Your computer can be set to use less power when you are not working. You control the power usage through the operating system installed on your computer and certain option settings in system setup (see System Setup). These periods of reduced power are called "sleep modes." NOTE: All components installed in the computer must support the hibernate and/or standby mode feature(s) and have the appropriate drivers loaded to enter either of these sleep modes. For more information, see the manufacturer's documentation for each component. l Standby. In this sleep mode, power is reduced or turned off for many components. However, system memory remains active. NOTE: Hibernate mode is only supported on computers with 4-GB of RAM or less. l Hibernate. This sleep mode reduces power consumption to a minimum by writing all data in system memory to a hard drive and then removing system power. Waking up from this mode restarts the computer, and the memory contents are restored. Operation then resumes where the computer left off when it entered the hibernation mode. l Shutdown. This sleep mode removes all power from the computer except a small auxiliary amount. As long as the computer remains connected to an electrical outlet, it can be automatically or remotely started. For example, the Auto Power On option in system setup (see System Setup) allows the computer to automatically start at a specified time. Also, your network administrator can remotely start your computer using a power management event such as Remote Wake Up. The following table lists the sleep modes and the methods you can use to wake the computer from each mode. Sleep Mode Wake-Up Methods (Windows XP) Standby l Press the power button l Auto power on l Move or click the mouse l Type on the keyboard l USB device activity l Power management event Hibernate l Press the power button l Auto power on l Power management event Shutdown l Press the power button l Auto power on l Power management event NOTE: For more information on power management, see your operating system documentation. Hyper-Threading and Dual-Core Technology Hyper-Threading is an Intel® technology that can enhance overall computer performance by allowing one physical processor to function as two logical processors, capable of performing certain tasks simultaneously. Dual-Core is an Intel technology in which two physical computational units exist inside a single CPU package, thereby increasing computing efficiency and multi-tasking ability. It is recommended that you use the Microsoft® Windows® XP Service Pack 1 (SP1) or higher operating system because Windows XP is optimized to take advantage of Hyper-Threading technology. While many programs can benefit from Hyper-Threading and dual-core technology, some programs may have not been optimized for them and may require an update from the software manufacturer. Contact the software manufacturer for updates and information about using Hyper-Threading or dual-core technology with your software. To determine whether your computer is using Hyper-Threading technology, check the system setup option for Hyper-Threading under the Performance tab (see System Setup). About RAID Configurations This section provides an overview of the RAID configuration that you might have selected when you purchased your computer. While there are many RAID configurations available in the computer industry for different types of uses, Dell offers RAID level 0, RAID level 1, or RAID level 5 on your Dell Precision computer. A RAID level 0 configuration is recommended for high-performance programs, and a RAID level 1 configuration is recommended for users that desire a high level of data integrity. A RAID level 5 configuration provides for both data integrity and high performance. RAID levels do not represent a hierarchy. A RAID level 5 configuration is not inherently better or worse than a RAID level 0 configuration. The Intel RAID controller on your computer can only create a RAID level 0 configuration using two or three physical drives. If a third drive is present, then that drive can be made part of a RAID level 0 configuration using the Intel RAID configuration program. If you have three drives and two are in a RAID level 1 configuration, the third drive can be used as a spare drive for the RAID configuration (see Creating a Spare Hard Drive). A RAID level 5 array must be made up of three drives. All drives must be the same type of drive; SAS and SATA drives cannot be mixed in a RAID array. The drives should also be the same size to ensure that the larger drive does not contain unallocated (and therefore unusable) space. RAID Level 0 RAID level 0 uses a storage technique known as "data striping" to provide a high data access rate. Data striping is a method of writing consecutive