Intel Core i7 is a family of three Intel Desktop x86-64 processors. Core i7 is the first Intel family to be released using the Intel Nehalem microarchitecture and is the successor to the Intel Core 2 family. All three models are quad-core processors.The Core i7 identifier applies to the initial family of processors codenamed Bloomfield,[4] due to be launched in Q4 2008. The moniker Core i7 does not have a deeper meaning, but continues the use of the successful Core 2 and Core brands.

Core i7 Features

Nehalem represents the largest architectural change in the Intel x86 family since the Pentium Pro in 1995. The Nehalem architecture has many new features. The ones that represent significant changes from the Core 2 include:
The FSB is replaced by a QuickPath interface.This means that motherboards must use a chipset that supports QuickPath. As of October 2008, only the Intel X58 does this.
The memory controller is on the processor, not in a separate chip, so the memory is directly connected to the processor.
The memory controller supports three channels of memory, and each channel can support one or two DDR3 DIMMs. This means that motherboards for the Core i7 have six DIMM slots instead of four, and that DIMMs should be installed in sets of three, not two.
The Core i7 only supports DDR3.
Core i7 is a single-die device: all four cores, the memory controller, and all cache are on a single die.
Core i7 cores re-implement Hyper-threading. Each of the four cores can process two threads simulaneously, so the processor appears to the OS as eight CPUs. This feature was present in the older Netburst architecure but was dropped in Core.
Core i7 has an on-die shared 8MB L3 cache.
Core i7 is not intended for multi-processor motherboards, so it has only one QuickPath interface.

A proposed Core i7 Release Date has not yet been determined, and may be delayed as far as October 2009 for the main-stream CPUs

Performance

A 2.93 GHz Core i7 940 system has been used to run a 3DMark Vantage benchmark and gave a CPU score of 17,966.[14] The 2.66 GHz Core i7 920 scores 16,294. A 2.4 GHz Core 2 Duo E6600 scores 4,300.[15]

AnandTech tested the Intel QuickPath Interconnect (4.8 GT/s version) and found the copy bandwidth using triple-channel 1066 MHz DDR3 was 12.0 GB/s. A 3.0 GHz Core 2 Quad system using dual-channel 1066 MHz DDR3 achieved 6.9 GB/s.[16]

Overclocking will be possible with the 900 series and a motherboard equipped with the X58 chipset. However, it will not be possible to use "performance" DDR3 DIMMs that require voltages higher than 1.65v, because the integrated memory controller within the Core i7 will be damaged.[17]

Intel has not yet given product names to the Lynnfield and Havendale processors. While they implement the Nehalem architecture, they may not be Core i7. These processors will use a different socket and will different supports chips, requiring a different motherboard design.[18]

Many early articles suggest that i7's design is not ideal for gaming performance. In a test done on leaked hardware, a Core i7 940 compared to a QX9770 shows the Core i7 is slower than Yorkfield clock for clock in 2 games while being faster in the other two. Difference in all cases are small.[19]

In the Super PI 1M test, a Core i7 920 running at 2.66 Ghz finished the test in 15.36 seconds, while a QX9770 (3.2 Ghz) did the test in 14.42 seconds.[20]