Caution - These procedures require that you handle components that are sensitive to static discharge. This sensitivity can cause the component to fail. To avoid damage, ensure that you follow antistatic practices as described in 2.3 Performing Electrostatic Discharge and Static Prevention Measures.
Physical layout of the CPUs, memory risers, and DIMMs
Memory riser population rules
Memory riser DIMM population rules
Rules for installing DIMMs across memory risers
DIMM rank classifications labels
Instructions for installing a DIMM
The physical layout of the CPUs, memory risers, and DIMMs is shown in CPU and Memory Riser Layout and Memory Riser DIMMs Physical Layout and Population Order.
Figure 4-1 CPU and Memory Riser Layout
Note - Only memory risers that are labeled “V2 Memory Riser” are supported in the Sun Server X2-4. Before installing memory risers in the server, ensure that the memory riser contains this label.
The system firmware checks if the installed CPUs are for the Sun Server X2-4. The system firmware raises a fault for memory risers whose model belongs with the other family of CPUs.
A maximum of two memory risers (numbered MR0 and MR1) are supported per CPU, thus allowing up to eight memory risers in a 4-CPU system, or up to four memory risers in a 2-CPU system.
Each memory riser slot in the server chassis must be filled with either a memory riser or filler panel, and each memory riser must be filled with DIMMs and/or DIMM filler panels. For example, in 2-CPU systems, empty CPU sockets (P1 and P3) must have associated memory riser slots populated with two riser filler panels per CPU.
Performance-oriented configurations should be configured with two memory risers per CPU. In configurations that do not require two memory risers per CPU, the following guidelines should be followed:
First populate riser slot MR0 for each CPU, starting with the lowest numbered CPU (P0).
The populate riser slot MR1 for each CPU, starting with the lowest numbered CPU (P0).
Figure 4-2 Memory Riser DIMMs Physical Layout and Population Order
Maximum memory operating speed is 1066 MHz. This also applies to supported DIMMs rated for higher speeds.
Supported DIMMs include single-, dual-, or quad-rank 4 GB, 8 GB, 16 GB and 32 GB JEDEC˘2013standard, DDR3 low voltage ECC RDIMMs.
All DIMMs on a CMOD must be the same density and organization.
Note - Do not mix dual-rank 16 GB DIMMs with quad-rank 16 GB DIMMs on a CMOD. Mixing DIMMs of different rank or density degrades performance.
Single-rank DIMMs (marked 1Rx8) and dual-rank DIMMs (marked 2Rx4) do not include heat spreaders.
Quad-rank DIMMs are marked 4Rx4 and include heat spreaders. DIMMs with heat spreaders have two U-shaped metal clips on the top of the DIMM.
Each memory riser supports up to 8 DIMMs, with a maximum 64 DIMMs for a 4-socket Sun Server X2-4.
DIMM slots are color coded with the following population order:
DIMM slots must be populated in matching pairs of identical DIMMs (from the same memory kit) within a processor.
The recommended DIMM population order, as depicted in Memory Riser DIMMs Physical Layout and Population Order is:
Install quad-rank DIMMs before dual-rank DIMMs on the same riser. Specifically, a DRAM channel with both rank types must have the quad-rank DIMM in the D0/D4 or D2/D6 slot.
Note - When a mixed quad-rank DIMM and dual or single rank DIMM are on the same memory riser, the quad-rank DIMM should be installed in slot0 of each channel.
Meeting these guidelines will provide the best system performance. Guidelines are listed in decreasing importance.
Provide some DIMMs on every memory riser.
Provide DIMMs on every DRAM channel (at least 4 DIMMs per memory riser).
For each CPU, have equal total gigabytes on the MR0 and MR1 risers. Memory bandwidth is 5% higher when all pairs of risers have balanced capacity.
Spread the memory capacity evenly across the CPUs so the operating system can distribute large memory tasks better.
Avoid mixing dual-rank and quad-rank DIMMs in the same memory riser.
For the Sun Server X2-4, the operating speed of the DIMMs does not decrease as more DIMMs are installed. For best memory performance, follow these simple guidelines to add or replace DIMMs in the server. Use one or more sizes of DIMMs, with an even number of DIMMs of each size.
Using the largest-capacity DIMMs, add two DIMMs per riser, starting at P0/MR0, continuing through P3/MR1, and then beginning again at P0/MR0 if necessary, until all of the largest-capacity DIMMs are placed.
For installations with one DIMM size, all DIMMs will be placed in this step. For installations with additional DIMMs of different sizes, continue to the next guideline step.
If you are adding or replacing quad-rank (16GB) DIMMs, they can be installed only in D0/D4 slots or D2/D6 slots, or else in DRAM channels where those slots already contain 16GB DIMMs.
Using DIMMs of the next largest capacity, add two DIMMs per riser, starting with risers with the fewest DIMMs and proceeding from P0/MR0, continuing through P3/MR1, and then beginning again at P0/MR0 if necessary, until there are no more DIMMs of this size, or all risers have four DIMMs.
As long as any riser has fewer than four DIMMs, keep repeating this step with the DIMMs of decreasing capacity. When all risers have four DIMMs, continue to the next guideline step.
Using DIMMs of the next largest capacity, add two DIMMs per riser to risers with the least total gigabytes. Start from P0/MR0, continuing through P3/MR1, and then begin again at P0/MR0 is necessary.
Repeat guideline step 3 with all remaining DIMMs, in decreasing order of DIMM capacity, until all DIMMs are placed.
The eight DIMMs supported on each memory riser card in the Sun Server X2-4 are divided into two logical DDR3 channels. The first logical channel contains DIMMs installed in slots D0, D1, D4 and D5. The second logical channel contains DIMMs installed in slots D2, D4, D6 and D7.When one or more DIMMs within a logical DDR3 channel are faulted, all four DIMMs within that logical channel will be disabled by BIOS on subsequent boots. This isolates the faulty component from the system to ensure that proper operation is not compromised by the presence of the faulty component.
Initially supported DIMMs for the Sun Server X2-4 are PC3L-type RDIMMs, which are DDR3 low-voltage DIMMs. Supported DIMM Size and Organization identifies supported DIMM sizes.
Table 4-1 Supported DIMM Size and Organization
The Sun Server X2-4 does not support the following DIMMs:
LR-DIMMs or UDIMM
DIMMs using 256 Mb or 512 Mb DRAM technologies
DDR3-800 MHz RDIMMs
DDR3-978 MHz RDIMMs
Use the following procedures to remove and install memory risers, DIMMs, and filler panels.
Caution - Whenever you remove a memory riser filler panel, replace it with another filler panel or a memory riser; otherwise, the server might overheat due to improper airflow.
The filler panel is partially ejected from the socket.
Caution - Whenever you remove a DIMM filler panel, replace it with another filler panel or a DIMM; otherwise, the server might overheat due to improper airflow.
Note - Located above the Fault Remind button is the Fault Remind button Power LED. When the Fault Remind button is pressed, the Power LED illuminates (green) to indicate that the remind circuitry is working correctly.
Figure 4-3 Fault Remind Button on the Air Divider
Figure 4-4 Removing the Memory Riser
The DIMM is partially ejected from the socket.
Figure 4-6 DIMM Socket Release and Alignment
1 DIMM connector slot
2 DIMM connector key
3 DIMM ejector lever
Caution - Whenever you remove a memory riser or DIMM, you should replace it with another memory riser or a DIMM or a filler panel; otherwise, the server might overheat due to improper airflow.
Caution - Be sure to install DIMMs in matched pairs of identical DIMM types (same part number).
Align the notch in the DIMM with the key in the connector. The notch ensures that the DIMM is oriented correctly.
Figure 4-7 Installing DIMMs
If the DIMM does not easily seat into the connector, verify that the notch in the DIMM is aligned with the key in the connector as shown in DIMM Socket Release and Alignment. If the notch is not aligned, damage to the DIMM might occur.
Figure 4-8 Installing a Memory Riser Module