Socket AM3 is a

CPU socket In computer hardware, a CPU socket or CPU slot contains one or more mechanical components providing mechanical and electrical connections between a microprocessor and a printed circuit board (PCB). This allows for placing and replacing the cen ...

for

AMD Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufactur ...

processors A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, a ...

. AM3 was launched on February 9, 2009 as the successor to Socket AM2+, alongside the initial grouping of

Phenom II Phenom II is a family of AMD's multi-core 45 nm processors using the AMD K10 microarchitecture, succeeding the original Phenom. Advanced Micro Devices released the Socket AM2+ version of Phenom II in December 2008, while Socket AM3 version ...

processors designed for it. The sole principal change from AM2+ to AM3 is support for

DDR3 SDRAM Double Data Rate 3 Synchronous Dynamic Random-Access Memory (DDR3 SDRAM) is a type of synchronous dynamic random-access memory (SDRAM) with a high bandwidth (" double data rate") interface, and has been in use since 2007. It is the higher-spe ...

. The fastest CPU for socket AM3 is the Phenom II X6 1100T. Like the previous AMD socket, the "AM3 Processor Functional Data Sheet" (AMD document number 40778) has not been made publicly available. The "Family 10h AMD Phenom™ Processor Product Data Sheet" (document 446878) has, but contains only a brief list of features of the Phenom, and does not contain any substantive technical data regarding socket AM3.

Compatibility

Socket AM3 breaks compatibility with AM2/AM2+ processors due to a subtle change in key placement. The AM3 socket has 941 pin contacts in a different layout while AM2+ processors have 940 pins.

Tom's Hardware ''Tom's Hardware'' is an online publication owned by Future plc and focused on technology. It was founded in 1996 by Thomas Pabst. It provides articles, news, price comparisons, videos and reviews on computer hardware and high technology. The si ...

removed the two obstructing key pins from an AM2+ Phenom processor in order to fit it into an AM3 socket. The processor did not work in the AM3 socket, but still worked in an AM2+ socket, suggesting that compatibility issues run deeper than merely the key pins. It is likely because the built-in memory controller in AM2/AM2+ processors only supports DDR2 (unlike AM3 processors, which support both DDR2 & DDR3 memory). In fact, a few motherboards were manufactured that supported both DDR2 and DDR3, however only one type could be used at a time. Despite using an AM3 socket and despite using a northbridge and southbridge found on AM3 motherboards, they support any AM2, AM2+, or AM3 processor. As AM3 processors also support DDR2, they are backwards-compatible with Socket AM2/AM2+, contingent upon a

BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the b ...

update for the motherboard. Manufacturers including Asus,

Gigabyte The gigabyte () is a multiple of the unit byte for digital information. The prefix '' giga'' means 109 in the International System of Units (SI). Therefore, one gigabyte is one billion bytes. The unit symbol for the gigabyte is GB. This definit ...

, and others have labeled existing AM2/AM2+ boards as being "AM3 Ready" or similar, indicating that BIOS support is provided for the specified boards. This allows existing AM2/AM2+ systems to upgrade the CPU without having to upgrade any other components.

Heatsink

The 4 holes for fastening the heatsink to the motherboard are placed in a rectangle with lateral lengths of 48 mm and 96 mm for AMD's sockets

Socket AM2 The Socket AM2, renamed from Socket M2 (to prevent using the same name as Cyrix MII processors), is a CPU socket designed by AMD for desktop processors, including the performance, mainstream and value segments. It was released on May 23, 2006, as ...

, Socket AM2+, Socket AM3,

Socket AM3+ AM3+ is a modification of the AM3 Socket, released in mid-2011, designed for CPUs which use the AMD Bulldozer microarchitecture and retains compatibility with AM3 processors. The Vishera line of AMD CPUs also all use Socket AM3+. It is the last A ...

and

Socket FM2 Socket FM2 is a CPU socket used by AMD's desktop ''Trinity'' and ''Richland'' APUs to connect to the motherboard as well as Athlon X2 and Athlon X4 processors based on them. FM2 was launched on September 27, 2012. Motherboards which fea ...

. Cooling solutions should therefore be interchangeable.

Socket AM3+

AM3+ is a modification of the AM3 socket. It has one additional pin for new

Bulldozer A bulldozer or dozer (also called a crawler) is a large, motorized machine equipped with a metal blade to the front for pushing material: soil, sand, snow, rubble, or rock during construction work. It travels most commonly on continuous track ...

-based AM3+ processors and is backwards-compatible with AM3 processors. It broke backwards-compatibility between AM3+ processors and AM2 and AM2+ motherboards because the processors do not support DDR2 memory.

References

External links

DailyTech post about Socket AM3

{{amdsock AMD sockets

Compatibility

Heatsink

Socket AM3+

See also

References

External links