NEC 5800/1000 Personal Computer User Manual


 
9
Modularization, redundancy and domain segmentation of the system clock
Minimizes downtime, and avoids multi-partition shutdown due to clock failure
Diagnostics of the error detection circuits
Substantial strengthening of data integrity
Main data paths of the A
3
chipset on the Express5800/1000 series
servers have been protected by ECC. When a single bit error is
detected, a hardware error correction is carried out. Furthermore,
paths between the A
3
chipset interfaces support multi-bit error
detection, and resending of errored data.
In addition to maintaining data integrity through these RAS
features, the Express5800/1000 series server has the ability to
run diagnostics on its own error detection circuits. During every
system boot, all error detection circuits are diagnosed for possible
failures. Without this feature, a failure in these circuits could result
in the inability to detect errors during system operation.
Through modularization and redundancy, system downtime, due to
clock failures, have been minimized. The Express5800/1000 series
server has taken it one step further. In many cases, when a system
is said to have a redundant clock, in actuality, only the oscillator
is redundant. Integral clock distribution mechanisms such as the
clock driver or the amplifier are, many times, not redundant. Such
a construct leads to the existence of system single point of failures.
The Express5800/1000 series servers have redundancy in not only
the oscillator, but also in the clock distribution mechanisms so that
system downtime can be minimized.
The 1320Xf system allows for the division of the system into two
16 processor segments, where one segment utilizes one system
clock, and the other 16 processor segment utilizes the remaining
system clock. A failure in a system clock therefore, will not result
in shutdown of the entire system.
Express5800/1000 Series
Redundant: Active, Standby
chipset
chipset
Clock
Distribution
Clock
Module
Clock
Module
Clock
Module
Clock
Module
Clock
Module
Clock
Module
Clock
Module
Hot
pluggable
Not hot
pluggable
Redundant Configuration A
Redundant Configuration A
Redundant Configuration B
Express5800/1000 Series
Redundant
Available on the 1320Xf/1160Xf
16 processor Domain Segmentation
Available on the 1320Xf
Redundant Configuration B
*
1
SPOF
Redundant: Active, Standby Redundant: Active, Standby
16 Processor Domain
Segmentation
Clock
Module
Clock
Module
16 Processor
Domain
16 Processor
Domain
chipset
chipset
chipset
chipset
chipset
chipset
chipset
chipset
chipset
chipset
chipset
chipset
chipset
chipset
Replacement of failed
component without
system halt
Minimized spread
of failure
*1: Hot plugging of the redundant oscillator is possible, however the hot plugging of the single clock driver is not possible
Clock
Distribution
Clock
Distribution
Clock
Distribution
Clock
Distribution
Clock
Distribution
Cell card
CPU CPU CPU CPU
Memory
Controller
Memory
Controller
Memory
Controller
Memory
Controller
Crossbar Card
Built-in high-speed error
check for inter-chipset
paths
PCI BOX
I/O
Router
I/O
Router
Cell
Controller
Crossbar
Controller
Crossbar
Controller
Crossbar
Controller
Crossbar
Controller
To
other CELL
controller