Introduction

AMD first launched the 955 Black Edition and 945 CPUs back in April both based on the 45nm Phenom II technology. With Intel seemingly forging ahead in terms of performance with its i7 series, AMD’s new products aim to compete more with Intel’s quad-core range and should offer a cheaper upgrade for users with an AM2+ platform as the AM3 CPUs are backwards compatible with AM2+ sockets.

The 955 BE, of which we are taking a look at today, is a Black Edition product, which in effect means that the CPU features a unlocked multiplier; a huge plus for the overclockers. A dual DDR2 and DRR3 memory controller is also crammed into the chip.

The 900 series of AMD processors are all quad-core CPUs with a 6MB L3 cache, 2MB larger than the 800 series and the stock speed of the 955 BE was the fastest until it was superseded very recently by the 965 BE which clocks in at a whopping 3.4GHz. However, today we focus on the 955, let's check it out.

Features

The industry's first true Quad core x86 processor 

• True quad-core and triple-core designed from the ground up for better communication between cores.
• Benefit: Cores can communicate on die rather than on package for better performance

AMD64 with Direct Connect Architecture

• Helps improve system performance and efficiency by directly connecting the processors, the memory controller, and the I/O to the CPU.
• Designed to enable simultaneous 32- and 64-bit computing
• Integrated Memory Controller
• Benefits: Increases application performance by dramatically reducing memory latency
• Scales memory bandwidth and performance to match compute needs
• HyperTransport™ Technology provides up to 16.0GB/s peak bandwidth per processor—reducing I/O bottlenecks
• Up to 37GB/s total delivered processor-to-system bandwidth (HyperTransport bus + memory bus)

AMD Balanced Smart Cache

• Shared L3 cache (either 6MB or 4MB)
• 512K L2 cache per core
• Benefit: Shortened access times to the highly accessed data for better performance.

AMD Wide Floating Point Accelerator

• 128-bit floating point unit (FPU)
• High performance (128bit internal data path) floating point unit per core.
• Benefit: Larger data paths and quicker floating point calculations for better performance.

HyperTransport™ Technology 

• One 16-bit link at up to 4000MT/s
• Up to 8.0GB/s HyperTransport™ I/O bandwidth; Up to 16GB/s in HyperTransport Generation 3.0 mode
• Up to 37GB/s total delivered processor-to-system bandwidth (HyperTransport bus + memory bus)
• Benefit: Quick access times to system I/O for better performance.

Integrated DRAM Controller with AMD Memory Optimizer Technology 

• A high-bandwidth, low-latency integrated memory controller
• Supports PC2-8500 (DDR2-1066); PC2-6400 (DDR2-800), PC2-5300 (DDR2-667), PC2-4200 (DDR2-533) or PC2-3200 (DDR2-400) SDRAM unbuffered DIMMs – AM2+
• Support for unregistered DIMMs up to PC2 8500(DDR2-1066MHz) and PC3 10600 (DDR3-1333MHz) – AM3
• Up to 17.1GB/s memory bandwidth for DDR2 and up to 21GB/s memory bandwidth for DDR3
• Benefit: Quick access to system memory for better performance.

AMD Virtualization™ (AMD-V™) Technology With Rapid Virtualization Indexing

• Silicon feature-set enhancements designed to improve the performance, reliability, and security of existing and future virtualization environments by allowing virtualized applications with direct and rapid access to their allocated memory.
• Benefit: Helps virtualization software to run more securely and efficiently enabling a better experience when dealing with virtual systems

AMD PowerNow!™ Technology (Cool’n’Quiet™ Technology)

• Enhanced power management features which automatically and instantaneously adjusts performance states and features based on processor performance requirements
• For quieter operation and reduced power requirements
• Benefit: Enables cooler and quieter platform designs by providing extremely efficient performance and energy usage.

AMD CoolCore™ Technology

• Reduces processor energy consumption by turning off unused parts of the processor. For example, the memory controller can turn off the write logic when reading from memory, helping reduce system power.
• Works automatically without the need for drivers or BIOS enablement.
• Power can be switched on or off within a single clock cycle, saving energy with no impact to performance.
• Benefit: Helps users get more efficient performance by dynamically activating or turning off parts of the processor.

Dual Dynamic Power Management™ 

• Enables more granular power management capabilities to reduce processor energy consumption.
• Separate power planes for cores and memory controller, for optimum power consumption and performance, creating more opportunities for power savings within the cores and memory controller.
• Benefit: Helps improve platform efficiency by providing on demand memory performance while still allowing for decreased system power consumption

Specifications

Processor	AMD Phenom II X4
Model	955
OPN Tray	HDZ955FBK4DGI
OPN PIB	HDZ955FBGIBOX
Operating Mode 32 Bit	Yes
Operating Mode 64 Bit	Yes
Revision	C2
Core Speed (MHz)	3200
Voltages	0.875 – 1.5V
Max Temps (C)	62
Wattage	125W
L1 Cache Size (KB)	128
L1 Cache Count	4
L2 Cache Size (KB)	415
L2 Cache Count	4
L3 Cache Size (KB)	6144
CMOS	45nm SOI
AMD Business Class	No
Black Edition	Yes