The latest generation of Intel x86-compatible processor, Core 2 Duo
microprocessor family, was introduced on July 27, 2006. The Core 2 Duo
processors include two cores, each core having 32 KB L1 data and 32 KB L1 code
caches, and both cores having shared 2 or 4 MB L2 cache.
The Core 2 Duo CPUs run at lower frequency than Pentium 4 processors,
but they offer excellent performance due to more efficient architecture:
- Each processor's core can execute up to 4 instructions per cycle.
- Shared L2 cache allows the same copy of data to be used by both cores. Another advantage of shared L2 cache is that more heavily loaded core can use bigger portion of L2 cache - up to the full size of the cache.
- 128-bit SSE instructions can be executed at sustained rate of one 128-bit instruction per cycle.
Core 2 Duo architecture includes other performance enhancing features.
One of these features is a "macrofusion". This feature allows the
processor to load and execute common instruction pairs as one
instruction.
Overall, despite of lower processor frequency, the performance of Core
2 Duo family is much higher than the performance of Pentium 4. Lower
processor speed of Core 2 Duo and Extreme processors also translates
into lower power consumption. Core 2 Duo E6600 and E6700 processors
have thermal design power 65 Watt (75 Watt for Core 2 Extreme x6800),
while less efficient Pentium 4 Extreme Edition 3.73 GHz has thermal
design power of 115 Watt.
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