Hardware Upgrades

Installing Additional Memory

The Evo Workstation W8000 has two Direct Rambus memory channels and uses Error Checking and Correcting (ECC) Direct Rambus Inline Memory Modules (RIMMS)

Dual Direct Rambus memory channels operate on the following three principles:

■Dual channels maximize performance by doubling the speed at which data is transferred to and from memory, unlike single channel systems. Memory hubs divide each main channel into two sub-channels. For example, channel A is divided into channel A-top and channel A-bottom, and channel B is divided into channel B-top and channel B-bottom. Each sub-channel consists of two RIMM sockets.

■Dual channels operate in unison, not independently, thus identical RIMMs must be installed in pairs across channels. For example, if you install a RIMM in RIMM socket 3 (channel B-top), you must also install an identical RIMM in RIMM socket 4 (channel A-top).

■Dual channels must have electrical continuity for your system to boot. For example, if you install identical RIMMs in RIMM sockets 3 and 4, but fail to install CRIMMs in RIMM sockets 1 and 2, the continuity will be broken and your system will not boot.

For more information on acceptable configurations, see “RIMM Installation Guidelines” and “Configurations for RIMM Installation” later in this chapter.

Compaq Evo Workstation W8000 Hardware Reference Guide

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