Specifications

Memory Riser QSSC-S4R Technical Product Specification
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x Sx - Indicates that the CPU socket is populated. S0 is CPU socket 1, S1 is CPU socket 2, S2 is CPU socket 3, and S3 is
CPU socket 4. A Y indicates the CPU socket is populated. Blank indicates the CPU socket is empty.
x S – Indicates whether the configuration supports the Spare mode of operation. Y indicates a Yes, N indicates a No.
x Intra M – Indicates whether the configuration supports the Intra Mirroring mode of operation. Y indicates a Yes, N
indicates a No.
x Inter M – Indicates whether the configuration supports the Inter Mirroring mode of operation. Y indicates a Yes, N
indicates a No.
x H - Indicates whether the configuration supports the Hemisphere mode of operation. Y indicates a Yes, N indicates a No.
x N - Identifies the total number of DIMMs that constitute the given configuration.
x X – Indicates that the DIMM is populated.
4.3.2 Temperature Sensors, FRU, and SPD
x Temperature Sensor: A two package temperature-sensing device provides a sensor at the left and right of the
DIMM sockets. Server management sees this as one sensor, measuring the temperature drop across the board,
which estimates the heat generated by the DIMMs.
x Field Replaceable Unit: An EEPROM device provides 256 bytes of programmable Field-Replaceable Unit (FRU)
space. This FRU is programmed during manufacturing to contain the board version and serial number but may
also be programmed to meet other integrator-specific needs.
x Serial Presence Detect Bus: The Serial Presence Detect (SPD) bus is a low frequency I2C chain that is routed to
each FBD memory channel. The Chipset acts as a master for the SPD bus.
4.3.3 Memory Riser LEDs
The S4R memory riser module also provides individual DIMM Act/fault LEDs indicating DIMM status. The table below
provides the LED definitions.
Table 11. S4R Memory Riser LED Indicators
Item LED Color/Behavior State
DIMM Fault LED 1B First
pair
Amber-On
1B DIMM fault
1D 1D DIMM fault
1A Second
pair
1A DIMM fault
1C 1C DIMM fault
2B Third
pair
2B DIMM fault
2D 2D DIMM fault
2A Fourth
pair
2A DIMM fault
2C 2C DIMM fault
Mirror Activity LED Green – On Mirror activity
Power LED Green – On Power is on
Off Power is off
Attention LED Amber – On Attention button is
pressed.
The DIMM slots on the memory riser are divided into upper right and lower left DIMM slot areas, numbered in pairs in
the order of 1B + 1D, 2B + 2D, 1A + 1C and 2A + 2C.
4.3.4 Power Rails
The main board supplies 12V, 5V, 3.3V, and 3.3V_AUX power to the memory riser. The Memory Riser has on-board
regulators to generate 1.1V, 1.5V, 1.8V and 0.75V. The Intel® 7500 Scalable Memory Buffer (Mill Brook) requires 1.1V,
1.8V and 1.5V, DDR3 DRAM requires 1.5V, and the DDR3 termination requires 0.75V. The MEMR FRU and SPD Bus
require 3.3V and 3.3V_AUX. DIMM LEDs and control circuits require 5V and 3.3V_AUX.