Installing Additional Memory - Compaq Evo W8000 Hardware Reference Manual

Installing Additional Memory

Compaq Evo Workstation W8000 Hardware Reference Guide
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.
Hardware Upgrades
2-5