SPEC CPU2006 software OS and BIOS Settings Descriptions for H3C Platform systems

Firmware / BIOS / Microcode Settings

Hardware Prefetch:

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.

Adjacent Sector 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.

Intel Turbo boost Technology:

Enabling this option allows the processor cores to automatically increase its frequency and increasing performance if it is running below power, temperature.

Intel Hyper Threading Technology:

Enabling this option allows to use processor resources more efficiently, enabling multiple threads to run on each core and increases processor throughput, improving overall performance on threaded software.

Lockstep Memory Mode (Default=Enabled)

Values for this BIOS setting can be: Lockstep memory mode uses two memory channels at a time and provides an even higher level of protection.You can adjust the mode to disabled.

cooling Configuration

The Baseboard Management Controller allows the user to adjust the fan speed manually,If the server is in a stressful environment, the CPU have high temperature, you can adjust the fan speed to 100%.

Memory Power Saving

Selects the memory power saving mode, Depends on the selected mode, the Power Down clock mode, CKE, and IBT are intialized accordingly, disable this featrue will keep memory in high performance mode.

C-State

Core C3, Core C6 can be disabled for latency-sensitive applications in order to minimize latency, but disable Core C-states can also significantly limit the amount of turbo when a low number of cores are active, C3 and C6 are recommended to enable in SPEC CPU benchmark.

Memory Patrol Scrub

This BIOS option allows the enabling/disabling of Memory Periodic Patrol Scrubber. The Memory Periodic Patrol Scrubber corrects memory soft errors so that, over the length of the system runtime, the risk of producing multi-bit and uncorrectable errors is reduced.

IMC (Integrated memory controller) Interleaving

This BIOS option controls the interleaving between the Integrated Memory Controllers (IMCs), Memory could be interleaved across sockets, memory controllers, DDR channels, Ranks. Memory is interleaved for performance and thermal distribution.

If IMC Interleaving is set to 2-way, addresses will be interleaved between the two IMCs.

If IMC Interleaving is set to 1-way, there will be no interleaving.

If IMC Interleaving is set to auto, it depends on the SNC (Sub NUMA Clustering) setting, when SNC is set to enbaled, the IMC Interleaving will be 1-way interleave, SNC is set to disabled, the IMC Interleaving will be 2-way interleave.

If SNC is disabled, IMC Interleaving should be set to 2-way. If SNC is enabled, IMC Interleaving should be set to 1-way.

Sub NUMA Cluster(SNC)

SNC breaks up the last level cache (LLC) into disjoint clusters based on address range, with each cluster bound to a subset of the memory controllers in the system. SNC improves average latency to the LLC and memory. SNC is a replacement for the cluster on die (COD) feature found in previous processor families. For a multi-socketed system, all SNC clusters are mapped to unique NUMA (Non Uniform Memory Access) domains.

SNC AUTO supports 1-cluster or 2-clusters depending on IMC interleave. SNC and IMC interleave both AUTO will support 1-cluster 2-way IMC interleave.

SNC Enable supports Full SNC (2 clusters) and 1-way IMC interleave. Utilizes LLC capacity more efficiently and reduces latency due to core/IMC proximity. This may provide performance improvement on NUMA-aware operating systems.

SNC disable supports 1-cluster and 2-way IMC interleave, the LLC is treated as one cluster.