Filter
Top Products
Dell
Dell PowerEdge M910 Technical Guide 20
memory buffers associated with the two populated sockets would be connected, and therefore only
16 DIMMs would be accessible.
To overcome this limitation with 2 CPUs, the M910 uses the FlexMem Bridge which allows CPU1 and
CPU2 to connect to the memory of their respective adjacent sockets (CPU3 and CPU4). The FlexMem
Bridge provides the following:
Two pass-through links for SMI
One pass-through link for QPI
The pass-through SMI links connect the two installed CPU’s to additional SMIs, therefore the CPU’s
will have the following memory attached:
CPU1 will have access to DIMMs [A1:A8], plus DIMMs [C1:C8] (those normally associated
with CPU3)
CPU2 will have access to DIMMs [B1:B8], plus DIMMs [D1:D8] (those normally associated
with CPU4)
The pass-through QPI link on the FlexMem Bridge provides increased performance for a 2P
configuration because it allows 2 full-bandwidth QPI links between CPU1 and CPU2 as opposed to a
single link. Figure 3 depicts the interconnection between the CPU sockets as well as connections
internal to the FlexMem Bridges. The FlexMem Bridges are only supported in sockets 3 and 4.
Figure 3. Diagram of FlexMem Bridge Routing
Modern processors are capable of tremendous workloads, and many types of utilization patterns such
as virtualization often run into memory capacity issues well before the processors reach a saturation
point. FlexMem Bridge technology was designed to assist those customers that have workloads that
are memory intensive.
Customers who scale their workloads in the future to a point where they would need additional
processing power can simply replace the FlexMem Bridge with additional processors to meet those
needs.
Due to power limitations, the PowerEdge M910 will only support two X7560 (130W) processors. In an
upgrade for a server with two 130W CPUs, the CPUs and the heatsink must be changed to the 95W or
105W CPUs. If the server has only the 95W or 105W CPUs, CPUs can simply be swapped out.
Buffer Buffer
PROC2
Buffer Buffer
PROC1
BufferBuffer
FlexMem Bridge
BufferBuffer
IOH
FlexMem Bridge