Adjacent Cache Line Prefetch:
This BIOS option allows the enabling/disabling of a processor mechanism to fetch the adjacent cache line within a 128-byte sector that contains the data needed due to a cache line miss. In some cases, setting this option to Disabled may improve performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.
C States:
Allows the processor to enter lower power states when idle. When set to Enabled (OS controlled) or when set to Autonomous (if hardware control is supported), the processor can operate in all available Power States to save power, but may increase memory latency and frequency jitter.
C1E:
When set to Enabled, the processor is allowed to switch to minimum performance state when idle. Otherwise, the performance state is at maximum when idle.
Collaborative CPU Performance Control:
Enables/disables the joint OS-System CPU power management control feature.
CPU Performance:
If supported by the CPU, Hardware P States is a performance-per-watt option that relies solely on the CPU to dynamically control individual core frequency.
CPU Power Management:
This BIOS setting allows configuration of various demand-based switching schemes. Maximum Performance maintains full voltage to processor internal components, even during periods of inactivity, eliminating the performance penalty associated with the phase transitions between high and low load.
Data Reuse:
Enabling this BIOS option reduces the frequency of L3 cache updates from L1. This may improve performance by reducing the internal bandwidth consumed by constantly updating L1 cache lines in L3. Since this results in more fetches to main memory, setting this option to Disabled may improve performance in some cases. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.
Energy Efficient Policy:
The CPU uses the setting to manipulate the internal behavior of the processor and determines
whether to target higher performance or better power savings.
Options are Performance, Balanced Performance, Balanced Energy and Energy Efficient.
Energy Efficient Turbo:
EET is a mode of operation where a processor's core frequency is adjusted within the turbo range based on workload.
Execute disable:
This is a security feature designed to prevent certain types of buffer overflow attacks by enforcing specific areas of memory that applications can execute code. In general, it is best to leave this option Enabled for the security benefits, as no real performance advantage has been detected by disabling this feature in BIOS
Hardware Prefetcher:
This BIOS option allows the enabling/disabling of a processor mechanism to prefetch data into the cache according to a pattern-recognition algorithm In some cases, setting this option to Disabled may improve performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.
High Bandwidth:
Enabling this option allows the chipset to defer memory transactions and process them out of order for optimal performance.
Logical Processor:
This BIOS setting enables/disables Intel's Hyper-Threading (HT) Technology. With HT Technology, the operating system can execute two threads in parallel within each processor core.
Memory Frequency:
This BIOS setting allows the memory to be clocked to the highest supported frequency.
Memory Patrol Scrub:
Memory Patrol Scrub Patrol Scrubbing is a custom System Profile option feature that scans the memory for bit errors and corrects them whenever possible. When set to Disabled, no patrol scrubbing will occur. When set to Standard Mode, the entire memory array will be scrubbed once in a 24 hour period. When set to Extended Mode, the entire memory array will be scrubbed every hour to further increase system reliability.
Memory Refresh Rate:
Selects the frequency at which the system memory controller performs the DRAM technology data refresh operation.
Monitor/Mwait:
Enables/disables use of the CPU opcodes defined to provide more efficient system software thread synchronization between multiple agents.
Node Interleaving:
This BIOS option allows the enabling/disabling of memory interleaving across CPU nodes. When disabled, each CPU chip can only access memory within its own node.
Snoop Mode:
Allows tuning of memory performances under different memory bandwidths. The optimal Snoop Mode
setting is highly dependent on workload type.
Cluser on Die (COD) is best used for highly NUMA optmizied workloads. This setting offers the best
case local memory latency, but worst case remote latency.
Oppportunistic Snoop Broadcast works well for workloads of mixed NUMA optimization. It offers
good balance of latency and bandwidth.
System Profile:
This BIOS option sets the performance and power management aggressiveness for the system. It is a collection of selections including a custom selection designed to allow customers to choose the ideal operating profile for their server system environment. It includes settings like CPU Power Management, Memory Frequency, Turbo Boost, C1E and C States.
Turbo Boost:
Intel Turbo Boost Technology is a processor feature which allows the processor to transition to a higher frequency than the processor's rate speed if the processor has available power headroom and is within temperature specifications. Disabling this feature will reduce power usage but will reduce the system's maximum achievable performance under some workloads.
Uncore Frequency:
Selects the running frequency of the CPU internal uncore.
Dynamic mode allows the processor to optimizee power resources across the cores and uncore during
runtime. The optimization of the uncore frequency to either save power or optimize performance is
influenced by the setting of the Energy Efficiency Policy.
Virtualization technology:
When this option is set to ENABLED, the BIOS will enable processor Virtualization features and provide the virtualization support to the OS through the DMAR table. In general, only virtualized environments such as VMware ESX, Microsoft Hyper-V, Red Hat KVM, and other virtualized operating systems will take advantage of these features. Disabling this feature is not known to significantly alter the performance or power characteristics of the system, so leaving this option Enabled is advised for most cases.