IBM x3850 X5, Руководство по внедрению

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Chapter 7. IBM System x3690 X5
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7.4 MAX5 considerations
On top of the half of a terabyte (TB) of memory that can be configured in the x3690 X5, an
additional half of a TB of memory can also be configured in the MAX5 memory expansion unit
and attached to the server to increase overall memory access performance and capacity.
MAX5 is best used with applications that can benefit from the increase in overall memory
capacity. The most significant performance gains come in applications, which
require the
additional memory that MAX5 can provide. If an application does not need the extra memory,
the potential for performance gains is reduced.
The best way to populate memory DIMMs in the server and the MAX5 depends greatly on the
manner in which the applications that are being run address memory and the total amount of
memory that is needed by the applications. However, you also need to consider the following
rules:
򐂰 Always populate the DIMM sockets in the server first before installing DIMMs in the MAX5.
Local memory has higher bandwidth and lower latency than MAX5 memory. MAX5
memory is limited by the speed of the QuickPath Interconnect (QPI) link.
򐂰 If possible, install DIMMs so that Hemisphere Mode is enabled. Without Hemisphere
Mode, performance can suffer considerably.
򐂰 The MAX5 can be used on an x3690 X5 that has only one processor installed. However,
you get the best performance by having both processors installed and installing memory to
both the system planar and the memory mezzanine.
򐂰 MAX5 adds an additional path to memory through dedicated QPI ports, which results in
potentially greater memory bandwidth. There might be instances where it is better to have
reserve DIMMs for use in the MAX5.
7.4.1 Before you attach the MAX5
Before you can attach and use the MAX5, the x3690 X5 requires that the firmware, which is
shown in Table 7-2, is in place. Perform firmware updates in the order listed.
Table 7-2 Minimum firmware levels to support the MAX5 memory expansion
Firmware type Version Build
1. IMM 1.20 YUOO75T
2. UEFI 1.21 MLE120B
3. FPGA 1.10 MLDU20EUS
Field Programmable Gate Array (FPGA) on the MAX5: The MAX5 also has FPGA
firmware that resides on it. The FPGA firmware is updated automatically when the server
to which it is attached has its FPGA firmware flashed. The default FPGA loaded onto the
MAX5 from the factory is for the System x3850 X5. You are required to reflash the FPGA
on your system x3690 X5 after the MAX5 is connected to it.
The server might fail to complete POST because of a significant difference in FPGA code
between the MAX5 and the server. Correct this problem by flashing the FPGA through the
IMM while the server is plugged into power but not powered on.