Supermicro X11DGQ User Manual page 82

Super X11DGQ User's Manual
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.
IO Directory Cache (IODC)
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
Select Enable to use "Sub NUMA Clustering" (SNC), which supports full SNC (2-cluster)
interleave and 1-way IMC interleave. Select Auto for 1-cluster or 2-cluster support depending
on the status of IMC (Integrated Memory Controller) Interleaving. The options are Disable,
Enable, and Auto.
XPT Prefetch
Select Enable for XPT (Extended Prediction Table) Prefetch support which will allow an
LLC request to be duplicated and sent to an appropriate memory controller based on the
recent LLC history to reduce latency. The options are Enable, Auto, and Disable.
KTI Prefetch
If this feature is set to Enable, the KTI prefetcher will preload the L1 cache with data
deemed relevant to allow the memory read to start earlier on a DDR bus in an effort to
reduce latency. The options are Enable and Disable.
Local/Remote Threshold
This feature allows the user to set the threshold for the Interrupt Request (IRQ) signal, which
handles hardware interruptions. The options are Disable, Auto, Low, Medium, and High.
Stale AtoS (A to S)
The in-memory directory has three states: I, A, and S states. The I (-invalid) state indicates
that the data is clean and does not exist in the cache of any other sockets. The A (-snoop
All) state indicates that the data may exist in another socket in an exclusive or modified
state. The S state (-Shared) indicates that the data is clean and may be shared in the
caches across one or more sockets. When the system is performing "read" on the memory
and if the directory line is in A state, we must snoop all other sockets because another
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