In
November 2008, Intel published a white paper describing a new feature,
incorporated in its latest release of Nehalem-based processors, called
Intel Turbo Boost Technology. This high performance technology
essentially allows processors to run faster than the base frequency by
dynamically controlling its clock rate under certain constraints. This
article attempts to demystify this popular design concept of 'dynamic
overclocking'.
When a processor is tweaked without add-on
hardware to run faster than its base configuration, the result is that
instead of processing x number of instructions per second (for which the
original design was built), it is now capable of handling x+n
instructions per second. In simple terms, it's going to process much
more and therefore, faster than what it was built for. Intel's
trademarked Turbo Boost Technology enables higher performance by making
available an increased processor core frequency, provided some
dependency conditions are met. Unlike manual overclocking by
manipulating clock speeds on the BIOS, dynamic overclocking is automatic
and is based upon constantly evaluating if the dependencies are met,
commonly referred to as dynamically assessing headroom. Let us explore
these dependencies in detail and find out how the Intel Turbo Boost
Technology works.
Working of Intel Turbo Boost Technology and Processor Dependencies
Unlike
overclocking which causes overheating of hardware making it prone to
damage, Intel Turbo Boost is a technology built into the design of the
processor versions that support it. The biggest benefit of this design
is faster performance without exceeding the electrical and thermal
specifications of the core, thus conserving energy when it is not
needed. However, the increased core frequency is constrained by the
following factors.
Estimated processor power and current consumption
Estimated processor temperature
Number of active processor cores (they dictate the maximum frequency)
If
the current application workload isn't keeping all cores fully busy and
pushing right up against the chip's Thermal Design Power (TDP is the
maximum amount of power the chip can withstand with help from the
cooling systems) limit, Turbo Boost can increase the clock speed of each
core individually to derive more performance out of the chip. Under the
above constraints of TDP, the processor can increase its clock speed in
steps of 133.33 MHz. All active cores in the processor will maintain
the same frequency. Whatever power the other two or three cores would
have consumed can be redirected over to the active cores, allowing them
to run at higher speeds. The highest performance state when requested by
the Operating System, activates the Intel Turbo Boost Technology. The
operating configuration, platform design and workload parameters dictate
how long the Intel Turbo Boost state will be maintained. Under ideal
conditions, the technology positively influences the performance of both
multithreaded and single-threaded workloads.
Advantages of Dynamic Overclocking
Intel
Turbo Boost Technology being a dynamic feature that kicks in when
certain conditions are met, the user cannot predict when the system will
switch to the "turbo mode". However, it still provides a solution such
that there's no compromise involved while choosing a dual core or quad
core processor. Dual core processors have greater clock speeds because,
the more number of cores in quad core meant increased power consumption
and caused overheating. One had to make a choice also between
applications that favored dual core or quad core. However, with Intel
Turbo Boost, any idle core would go into a lower power state and the
active cores would be dynamically overclocked thus eliminating
compromise! A new version of Core i7 processor has a feature that
enables operation at base clock speed when the system is battery-powered
but switches to Turbo Boost, doubling its clock speed, when plugged in.
How to Use Turbo Boost Technology
The important thing to know is that Intel Turbo Boost technology will work only on the following supported processor families.
i7 mobile and desktop processors
i7 processor extreme edition
i7 mobile processor extreme edition
i5 mobile and desktop processors
In
the above processors, the Intel Turbo Boost Technology is enabled by
default. A BIOS switch can be used to disable it, however, this is not
recommended. There are no further settings available for the user to
intervene in the operation, activation or frequency specification of the
Intel Turbo Boost Technology. An optimized version of the original
Intel Turbo Boost Technology, Intel Turbo Boost Technology 2.0 is
incorporated in 2nd Generation Intel core processors, providing even
more performance. To view the Turbo Boost in action, you may download a
tool known as the Intel Turbo Boost Technology Monitor. The Intel
Processor Identification Utility will enable you to view the highest
Turbo Boost frequency on the supported processor.
If you're only
using your PC for Internet browsing, working on a few word processing
and spreadsheet applications and mostly just checking your email, you
might not find much use for the Intel Turbo Boost Technology although
you may prefer it to manual overclocking. However, if you're mostly
working with HD media or video-intensive applications, 3D gaming or
multitasking compute-intensive applications, then this on-demand
performance technology that intelligently allocates extra processing
power to match workload, is as futuristic as it gets.
Traditionally
the playing field of gaming enthusiasts and power users, overclocking
has found its way into modern-day processors for good. Preset processor
clock speeds seem to have become a thing of the past. Adaptive
performance of processors to suit the demands of the user in a dynamic
and flexible way seems to be the future.
By Preeti Sunil
