Chapter 4: BIOS
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Degrade Precedence
Use this feature to select the degrading precedence option for Ultra Path Interconnect (UPI)
connections. Select Topology Precedent to degrade UPI features if the system options
are in conflict. Select Feature Precedent to degrade UPI topology if system options are in
conflict. The options are
Topology Precedence
and Feature Precedence.
Link L0p Enable
Select Enable for the system BIOS to enable Link L0p support which will allow the CPU
to reduce the UPI links from full width to half width in the event when the CPU's workload
is low in an attempt to save power. This feature is available for the system that uses Intel
processors with UPI technology support. The options are
Disable
, Enable, and Auto.
Note
: You can change the performance settings for non-standard applications by us-
ing this parameter. It is recommended that the default settings be used for standard
applications.
Link L1 Enable
Select Enable for the BIOS to activate Link L1 support which will power down the UPI links
to save power when the system is idle. This feature is available for the system that uses
Intel processors with UPI technology support. The options are
Disable
, Enable, and Auto.
Note
: Link L1 is an excellent feature for an idle system. L1 is used during Package
C-States when its latency is hidden by other components during a wakeup.
XPT Remote Prefetch
Select Enable to support XPT (Extended Prediction Table) Remote Prefetch which will
allow an LLC request to be duplicated and sent to an appropriate memory controller in
a remote machine based on the recent LLC history to reduce latency. The options are
Disable, Enable, and
Auto
.
KTI Prefetch
Select Enable for the KTI prefetcher to preload the L1 cache with data deemed relevant
which will allow the memory read to start earlier on a DDR bus in an effort to reduce latency.
Select Auto for the KTI prefetcher to automatically preload the L1 cache with relevant data
whenever it is needed. The options are Disable, Enable, and
Auto
.
Local/Remote Threshold
Use this feature to set the threshold for the Interrupt Request (IRQ) signals, which handle
hardware interruptions. The options are Disable,
Auto
, Low, Medium,
and High.
