IBM Power 720 Express, Обзор

Страница: 74 / 206

60
IBM Power 720 and 740 Technical Overview and Introduction
The bandwidth figures for the caches are calculated as follows:
򐂰 L1 cache: In one clock cycle, two 16-byte load operation and one 16-byte store operation
can be accomplished. By using a 4.284 GHz processor card, the formula is as follows:
(2 * 16 B + 1 * 16 B) * 4.284 GHz = 205.632 GBps
򐂰 L2 cache: In one clock cycle, one 32-byte load operation and one 16-byte store operation
can be accomplished. By using a 4.284 GHz processor card, the formula is as follows:
(1 * 32 B + 1 * 16 B) * 4.284 GHz = 205.632 GBps
򐂰 L3 cache: One 32-byte load operation and one 32-byte store operation can be
accomplished at half clock speed. By using a 4.284 GHz processor card the formula is as
follows:
(1 * 32 B + 1 * 32 B) * (4.284 GHz / 2) = 137.088 GBps
򐂰 Memory: The Power 720 and Power 740 system use one memory controller of the
processor. The memory controller is connected to a buffer chip that uses four
ports with 8 bytes. Each buffer chip connects to four DIMMs that are running at 1066 MHz,
with two DIMMs being active at a given point in time. See Figure 2-8 on page 54 for
reference. The bandwidth formula is calculated as follows:
1 memory controller * 4 ports * 8 bytes * 2 DIMMs * 1066 MHz = 68.224 GBps
2.4 Capacity on Demand and Capacity Backup offering
The only available Capacity on Demand feature for Power 720 and Power 740 systems is
Capacity Backup (CBU) for IBM i. For Power 720 and Power 740 systems used with AIX or
Linux, Capacity on Demand is not supported.
The Power 720 and Power 740 systems CBU designation can help meet your requirements
for a second system to use for backup, high availability, and disaster recovery. It enables you
to temporarily transfer IBM i processor license entitlements and 5250 Enterprise Enablement
entitlements purchased for a primary machine to a secondary CBU-designated system.
Temporarily transferring these resources instead of purchasing them for your secondary
system can result in significant savings. Processor activations cannot be transferred.
The CBU Specify FC 0444 is available only as part of a new server purchase. Certain system
prerequisites must be met, and system registration and approval are required before the CBU
Specify feature can be applied on a new server.
For information about registration and other details, see the following site:
http://www.ibm.com/systems/power/hardware/cbu
IBM i only: Capacity Backup Offering applies to IBM i only.