Release Notes
13 Memory Errors and Dell PowerEdge YX4X Server Memory RAS Features
available spare rows. This is done to ensure that PowerEdge servers have a robust self-healing memory
ecosystem.
When the server platform determines that a DRAM row has one or more faulty cells, it can instruct the
DRAM to electrically swap out the old row and replace it with a new one. This happens through
electrical fusing and is a permanent process. Additionally, the PPR process can only occur at the
beginning of a boot process – before memory training and test can occur. Similar to Memory Page
Retirement, deeming which DRAM require Post Package Repair is determined by a proprietary Dell
algorithm that takes into account correctable error rates and error patterns.
Figure 7 - PPR for a row in a bank group of a 4Gb x4 device
PPR is always available on PowerEdge server platforms that support it and will automatically execute
after a system reboot if BIOS deems it necessary. Note that BIOS may automatically promote a warm
reset to a cold reset during this process. In order for PPR to successfully execute, it is recommended that
users do not swap or replace DIMMs between boots when receiving memory error event messages,
unless instructed to do so by Dell technical support personnel.
In addition to PPR, the PowerEdge server memory self-healing process also includes memory re-training.
Memory training is the process by which the CPU initializes, calibrates, and tunes the link between itself
and the memory modules. While performing full memory training can help to ensure that the memory
bus operates at the highest level of signaling integrity, it is also a time-consuming process that directly
impacts server boot times. Therefore, PowerEdge servers only perform this step when necessary, such
as during the memory self-healing process.
Machine Check Architecture Recovery
MCA Recovery Feature Support Table
Platforms Supported
Intel Platforms:
(Xeon SP Gold, Platinum Families Only)
AMD Platforms:
DIMMs Supported
x4 DIMMs:
x8 DIMMs: