User's Manual

Performance
The maximum number of usable DIMM slots, and therefore the maximum amount of memory for
any particular configuration is tied to the number of processors used in the configuration. In addition,
the conjoined blade products all have minimum processor recommendations (oner per conjoined
blade) for best performance.
There are 12 DIMMs associated with each processor. Each processor has DIMM pairs A through
F. A processor must installed to access its associated memory. A processor can be installed without
memory as long as one of the processors in the conjoined system has memory.
For best performance, the minimum recommendation is a quad of DIMMs for each processor
installed in a conjoined blade product. For best performance (not required), load only the same
type (size) of DIMMs throughout the system. Uniform memory (selected in the memconfig
interleaving options) is supported with a total memory capacity equal to a "power of two" (loading
4, 8, 16, 32, or 64 DIMMs at a time). Therefore, for best performance, if using the uniform memory
selections, load a quad (even better two quads) of DIMMs for each processor. To obtain the fastest
memory access, load a total memory capacity equal to a power of four (4, 16, 64).
IMPORTANT: The system will boot with memory loaded on only one processor. However, from
a performance perspective, this is not a recommended configuration.
To enable Double DRAM chip sparing, for all the DIMMs loaded in the system, use only 4GB,
8GB, or 16GB DIMMs.
The 10GigE LOMs that have jumbo frames enabled require 1GB of main memory for each port
(8GB/server blade). Anything below this minimum results in insufficient memory and a hang either
during the HP-UX boot or during the I/O configuration for the Integrity BL8x0c i4 systems. For
example, the minimum memory configuration for the Integrity BL860c i4 is 8GB, for the BL870c
i4 is 16GB, and for the BL890c i4 is 32GB.
Minimum memory requirements assume the Flex-10/FlexFabric adapters are not installed. Increase
the minimum required memory by 2GB for each Flex-10/FlexFabric mezzanine card that is installed
into the system.
DIMM pair load order
Figure 1 DIMM quad load order
Installing internal components 45