Socket AM3+

Socket AM3+ is a modification of Socket AM3, which was released on February 9, 2009. AM3+ was released in mid-2011 designed for CPUs which use the AMD Bulldozer microarchitecture and retains compatibility with processors made for AM3. The Vishera line of AMD CPUs also all use Socket AM3+. It is the last AMD socket for which Windows XP support officially exists.

Technical specifications
The AM3+ Socket specification contains a few noteworthy design changes over its AM3 predecessor. The 942 pin count for the AM3+ is an increase of one compared to the AM3 Socket layout. The AM3+ Socket has larger pin socket diameter of 0.51 mm compared to 0.45 mm with the AM3 Socket. There is a faster serial link of 3400 kHz from the CPU to the power controller, compared to 400 kHz. The AM3+ Socket offers improved power regulation and power quality specifications, including an increased maximum current support of 145 A versus 110 A. There is also a redesigned CPU cooler retention harness allowing for slightly better airflow for CPU cooling, while retaining cooler backward compatibility.

Some manufacturers have attempted to bring AM3+ support to some of their AM3 technology motherboards via use of the AM3+ socket and a BIOS upgrade. AM3+ CPUs are not mechanically compatible with AM3 sockets as AM3+ CPUs have an additional pin that the AM3 socket can not accommodate. Another issue is the use of the sideband temperature sensor interface for reading the temperature from the CPU. Therefore, some CPU PWM fan headers may only run at full speed. Also, certain power-saving features may not work, due to lack of support for rapid VCORE switching.

AM3+ CPUs could not operate properly in many systems designed for AM2+ or AM2 CPUs due to the AM3+ CPUs' DDR3 memory controller being incompatible with the DDR2 memory generally used by AM2 and AM2+ boards.

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, Socket AM2+, Socket AM3, Socket AM3+ and Socket FM2. Cooling solutions should therefore be interchangeable.