Dell EMC PowerEdge R550 Reference Manual page 8

Table 5. Processor Settings details (continued)
Option
Directory Mode
Kernel DMA Protection
Adjacent Cache Line Prefetch
Hardware Prefetcher
DCU Streamer Prefetcher
DCU IP Prefetcher
Sub NUMA Cluster
MADT Core Enumeration
UPI Prefetch
XPT Prefetch
LLC Prefetch
Dead Line LLC Alloc
Directory AtoS
Logical Processor Idling
8 Pre-operating system management applications
Description
Enables or disables the directory mode. This option is set to
Enabled by default.
When set to Enabled, using IOMMU, BIOS and Operating
System will enable direct memory access protection
for DMA capable peripheral devices. Enable IOMMU Support
to use this option. When set to Enabled, using
Virtualization Technology, BIOS and Operating System will
enable direct memory access protection for DMA capable
peripheral devices.
Enable Virtualization Technology to use this option. This
option is set to Disabled by default. It is enabled for Secure
Launch (Firmware Protection) support on Windows 2022.
Optimizes the system for applications that need high
utilization of sequential memory access. This option is set
to Enabled by default. You can disable this option for
applications that need high utilization of random memory
access.
Enables or disables the hardware prefetcher. This option is set
to Enabled by default.
Enables or disables the Data Cache Unit (DCU) streamer
prefetcher. This option is set to Enabled by default.
Enables or disables the Data Cache Unit (DCU) IP prefetcher.
This option is set to Enabled by default.
Enables or disables the Sub NUMA Cluster. This option is set
to Disabled by default.
Specifies the MADT Core Enumeration. This option is set
to default in Round Robin. Linear option supports industry
core enumeration whereas, Round Robin option supports Dell
optimized core enumeration.
Enables you to get the memory read started early on DDR
bus. The Ultra Path Interconnect (UPI) Rx path spawns
the speculative memory that is read to Integrated Memory
Controller (iMC) directly. This option is set to Enabled by
default.
This option is set to Enabled by default.
Enables or disables the LLC Prefetch on all threads. This
option is set to Enabled by default.
Enables or disables the Dead Line LLC Alloc. This option is set
to Enabled by default. You can enable this option to enter the
dead lines in LLC or disable the option to not enter the dead
lines in LLC.
Enables or disables the Directory AtoS. AtoS optimization
reduces remote read latencies for repeat read accesses
without intervening writes. This option is set to Disabled by
default.
Enables you to improve the energy efficiency of a system. It
uses the operating system core parking algorithm and parks
some of the logical processors in the system, which in turn
allows the corresponding processor cores to transition into a
lower power idle state. This option can only be enabled if the
operating system supports it. It is set to Disabled by default.