Chapter 6: BIOS
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Link L1 Enable
Select Enable to enable Link L1 (Level 1 link). The options are Disable, Enable, and
Auto
.
IO Directory Cache
Select Enable for the IODC (I/O Directory Cache) to generate snoops instead of generating
memory lockups for remote IIO (InvIToM) and/or WCiLF (Cores). Select Auto for the IODC to
generate snoops (instead of memory lockups) for WCiLF (Cores). The options are Disable,
Auto
, Enable for Remote InvItoM Hybrid Push, InvItoM AllocFlow, Enable for Remote
InvItoM Hybrid AllocNonAlloc, and Enable for Remote InvItoM and Remote WViLF.
SNC
Sub NUMA Clustering (SNC) is a feature that breaks up the Last Level Cache (LLC) into
clusters based on address range. Each cluster is connected to a subset of the memory
controller. Enabling SNC improves average latency and reduces memory access congestion
to achieve higher performance. Select Auto for 1-cluster or 2-clusters depending on IMC
interleave. Select Enable for Full SNC (2-clusters and 1-way IMC interleave). The options
are
Disable
, Enable, and Auto.
XPT Prefetch
XPT Prefetch speculatively makes a copy to the memory controller of a read request being
sent to the LLC. If the read request maps to the local memory address and the recent
memory reads are likely to miss the LLC, a speculative read is sent to the local memory
controller. The options are
Disable
and Enable.
KTI Prefetch
KTI Pretech enables memory read to start early on a DDR bus, where the KTI Rx path
will directly create a Memory Speculative Read command to the memory controller. The
options are Disable and
Enable
.
Local/Remote Threshold
This feature allows the user to set the threshold for the Interrupt Request (IRQ) signal, which
handles hardware interruptions. The features are Disable, Enable,
Auto
, Low, Medium,
and High.
Stale AtoS
This feature optimizes A to S directory. When all snoop responses found in directory A
are found to be RspI, then all data is moved to directory S and is returned in S-state. The
options are
Disable
, Enable, and Auto.
