CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [82]
For AMD’s first quad-core desktop processor, called the Phenom, AMD decided to have each CPU core possess its own L1 and L2 caches, but have all four cores share an L3 cache to facilitate communication between cores. This is why AMD refers to the Phenom as a native quad-core processor. The Phenom series of processors are all 64-bit CPUs that feature the AMD64 technology also found in the Athlon 64 CPUs.
The Phenom series processors have an integrated memory controller that supports two channels of DDR2 memory. With the inclusion of an integrated memory controller, the Phenom processors do not possess a traditional frontside bus. Instead, they use the same HyperTransport bus that the Athlon 64 / Opteron series of processors have. Phenom processors are supported by AMD’s Socket AM2+ or Socket AM3. The CPU may also use Socket AM2, but this may incur a performance penalty.
AMD refers to a Phenom processor with four cores as a Phenom X4. A Phenom X3 also exists and, as the name suggests, it possesses only three cores. In reality, the Phenom X3 is a quad-core processor with one of the cores shut off due to a defect. As such, AMD sells the Phenom X3 processors at a discount compared to the Phenom X4.
Similar to Intel’s Extreme Edition CPUs for enthusiasts, AMD offers versions of the Phenom dubbed Black Edition. Not only are the Black Edition CPUs in the higher-end of their CPU range, but they also feature an unlocked clock multiplier allowing for fine-tuned overclocking.
AMD Phenom II
The Phenom II is a revision of the Phenom with a few improvements (see Figure 5-55). It includes triple the amount of L3 cache as the original Phenom, support for Intel’s SSE4a instructions, increased HyperTransport bus speeds, and an enhanced memory controller that can support two channels of DDR2 or DDR3 memory.
Figure 5-55 AMD Phenom II
The Phenom II is built using a 45-nm process instead of the 65-nm process used with the original Phenom. The Phenom II is supported by Socket AM3 and AM2+; however, the CPU only supports DDR3 memory when using Socket AM3.
Like the Phenom before it, the Phenom II is available in both an X4 quad-core version and an X3 triple-core version. But unlike the Phenom, the Phenom II is also available in an X2 dual-core version. Enthusiast Black Editions of all Phenom II configurations are also available.
Intel Core i7
Intel’s Core i7 family of processors is based off of a new microarchitecture called Nehalem, which succeeds Intel’s Core microarchitecture. Like AMD’s Phenom series of processors, the Core i7 is a native quad-core processor and all four cores share an L3 cache. This processor is Intel’s first to feature an integrated memory controller. The memory controller supports up to three channels of DDR3 memory.
The Core i7 also marks the return of hyperthreading to Intel’s CPUs (see Figure 5-56). With hyperthreading, each individual core can support two simultaneous threads, which, in aggregate, allows a single Core i7 to support up to eight simultaneous threads.
The processor features a large 8-MB L3 cache and was first manufactured using a 45-nm process. Intel designed a new 1366-pin socket for the Core i7 family of processors, called LGA 1366. Like the Core 2 Quad before it, the Core i7 is a 64-bit CPU conforming to the Intel-64 standard, meaning that it can also run 32-bit code.
Figure 5-56 Intel Core i7
With Nehalem, Intel has done away with the traditional frontside bus and replaced it with a technology they named QuickPath Interconnect (QPI). QPI is very similar to the HyperTransport bus found on the Opteron and Phenom series of processors.
Intel Celeron
Intel uses the brand Celeron for its entire family of lower-end CPUs. There are Celerons based on the Pentium II, Pentium III, Pentium 4, Pentium-M, Core and Core 2 Duo. The first Celerons were SEC, but