Intel Core i7 975 CPU Review :: Features

• Intel Turbo Boost technology
• Intel Virtualization Technology
• Enhanced Intel SpeedStep technology
• Execute Disable Bit
• Intel 64 architecture
• 45nm process
• Speed 3.33GHz
• Quick Path Interconnect speed 6.4GT/s
• HyperThreading Yes
• Quad Core: Yes
• Intel Wide Dynamic Execution
• Very deep out of order execution
• Enhanced Branch prediction
• Optimized for 32-bit applications running on advanced 32-bit operating systems
• Intel Smart Cache
• 32KB Data L1 Cache per core (128KB Data L1 Cache total)
• 32KB Instruction L1 cache per core (128KB Instruction L1 Cache total)
• 256KB L2 cache per core (1MB L2 Cache total)
• 8MB Level 3 Cache
• Intel Advanced Digital Media Boost
• Enhanced floating point and multimedia unit for enhanced video, audio, encryption and 3D performance
• New accelerators for improved string and text processing operations
• Power Management capabilities
• System Management mode
• Multiple low-power states
• 8-way cache association provides improved cache hit rate on load/store operations
• System Memory Interface
• Memory controller integrated in processor package
• 3 Channels
• 2 DIMMs/ channel supported (6 total)
• 24GB maximum memory supported
• Support unbuffered DIMMs only
• Single Rank and Dual Rank DIMMs supported
• DDR3 speeds of 800/1066MHz supported
• 512Mb, 1Gb, 2Gb Technologies/densities supported
• 1366-Land package

Intel manufactures their Core i7 series on a 45nm process at their Fabs. The Core i7 CPU has 731 million transistors on a die 263mm2 in size. The transistor count and die size is the same for all Core i7 CPUs from the 975 to the 920. These are the first true quad core CPUs from Intel, with previous Intel Core 2 Quad CPUs having two processor cores on each of two packages on the same processor.

Each core on the Core i7 975XE has 32KB of L1 Data and 32KB of L1 Instruction cache, bringing the total to 256KB for all four cores. Level 2 Cache is 256KB per core bringing the total to 1MB on the Nehelam core. Intel's Core i7 processors have a shared “Smart Cache” of 8MB that feeds all four cores on the processor. The Core i7 family has HyperThreading which allows the CPU to work on two software threads at a time, effectively doubling the number of cores. A Core i7 can work on 8 threads.

One major change with the Core i7 is the memory controller has moved to the processor rather than the motherboard's Southbridge as on previous Intel CPUs. The memory controller on the CPU now supports Triple-Channel memory, which allows the Core i7 to have increased memory bandwidth over similarly clocked dual-channel memory. The maximum bandwidth on DDR3-1333MHz in Triple Channel mode is 25GB/second.

For many years the interface between which the motherboard communicates with the CPU has been the Front Side Bus. Intel maxed out their FSB with the QX9770 at 1600MHz. With the advent of the Core i7 CPU, the Quick Path Interconnect replaced the FSB. The Core i7 975XE has a QPI of 6.4GT/second (Gigatransfers). QPI is similar to the HyperTransport system used on AMD CPUs and delivers up to 25.6GB/second transfer between the IO and the CPU.

The Core i7 CPU comes in a Land Ball Grid Array of 1366 Pins. Previous Intel CPUs had 775 pins and used a LGA-775 interface. The new interface is not compatible with the LGA-775 interface so new motherboards based on the X58 chipset are required to use the Core i7 975 eXtreme Edition. The various motherboard manufacturers including Intel, ASUS, Gigabyte and others support the new 975XE CPU with their latest BIOS. Intel has now released five CPUs on the Core i7 family from the mainstream Core i7 920 to today's Core i7 975XE and Core i7 950 which is a speed-bumped Core i7 940. The near future will have lesser priced Core i5 CPUs with lower clock speeds but that will require a new motherboard platform and is not due until September. The performance on those CPUs will be less than the current i7 CPUs. Here's a chart of the available Intel Core i7 CPUs including the Clock speed, the QPI speed and the current pricing on the Internet of each CPU.