Specifications
Computer Architecture and Maintenance (G-Scheme-2014)
With Hyper-Threading, a microprocessor's  "core" processor can execute two 
(rather than one) concurrent streams (or thread s) of instructions sent by the operating 
system. Having two streams of execution units to work on allows more work to be 
done by the processor during each clock cycle . To the operating system, the Hyper-
Threading  microprocessor  appears  to   be   two  separate  processors.   Because   most   of 
today's operating systems (such as Windows and Linux) are capable of dividing their 
work   load   among   multiple   processors   (this   is   called   symmetric   multiprocessing 
or SMP ), the operating system simply acts as though the Hyper-Threading processor is 
a pool of two processors.
HT Technology was introduced on Xeon workstation-class processors with a 533 
MHz system bus in March 2002. It found its way into standard desktop PC processors 
starting with the Pentium 4 3.06 GHz processor in November 2002. HT Technology 
predates multicore processors, so processors that have multiple physical cores, such as 
the Core 2 and Core i Series, may or may not support this technology depending on the 
specific processor version. A quad-core processor that supports HT Technology (like 
the Core i Series) would appear as an 8-core processor to the OS; Intel’s Core i7-3970X 
has six cores and supports up to 12 threads. Internally, an HT-enabled processor has 
two sets of general-
purpose   registers, 
control   registers, 
and   other 
architecture 
components   for 
each core, but both 
logical   processors 
share   the   same 
cache,   execution 
units,   and   buses. 
During   operations, 
each   logical 
processor handles a 
single thread.
Prepared By – Prof. Manoj.kavedia (9860174297 – 9324258878 ) (www.kavediasir.yolasite.com)
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