Vol 1

Intel® Xeon® Product 2800/4800/8800 v2 Product Family 27
Datasheet Volume One, February 2014
Technologies
instructions make Intel AES-NI simple to implement, with reduced code size. This helps
reducing the risk of inadvertent introduction of security flaws, such as difficult-to-
detect side channel leaks.
2.2.4 Execute Disable Bit
Intel's Execute Disable Bit functionality can help prevent certain classes of malicious
buffer overflow attacks when combined with a supporting operating system.
• Allows the processor to classify areas in memory by where application code can
execute and where it cannot.
• When a malicious worm attempts to insert code in the buffer, the processor
disables code execution, preventing damage and worm propagation.
2.3 Intel® Hyper-Threading Technology
The processor supports Intel® Hyper-Threading Technology (Intel® HT Technology),
which allows an execution core to function as two logical processors. While some
execution resources such as caches, execution units, and buses are shared, each
logical processor has its own architectural state with its own set of general-purpose
registers and control registers. This feature must be enabled via the BIOS and requires
operating system support.
For more information on Intel Hyper-Threading Technology, see
http://www.intel.com/products/ht/threading_more.htm.
2.4 Intel
®
Turbo Boost Technology
Intel Turbo Boost Technology is a feature that allows the processor to opportunistically
and automatically run faster than its rated operating frequency if it is operating below
power, temperature, and current limits. The result is increased performance in multi-
threaded and single threaded workloads. It should be enabled in the BIOS for the
processor to operate with maximum performance.
2.4.1 Intel
®
Turbo Boost Operating Frequency
The processor’s rated frequency assumes that all execution cores are running an
application at the thermal design power (TDP). However, under typical operation, not
all cores are active. Therefore most applications are consuming less than the TDP at the
rated frequency. To take advantage of the available TDP headroom, the active cores can
increase their operating frequency.
To determine the highest performance frequency amongst active cores, the processor
takes the following into consideration:
• The number of cores operating in the C0 state.
• The estimated current consumption.
• The estimated power consumption.
•The temperature.
Any of these factors can affect the maximum frequency for a given workload. If the
power, current, or thermal limit is reached, the processor will automatically reduce the
frequency to stay with its TDP limit.