Athlon II X2 is similar to Phenom II CPU, but with two processing cores and no L3 cache. According to the manufacturer, Athlon II X2 isn't a Phenom II with its L3 cache and some cores disabled, but a CPU manufactured from ground up. Thus, it has die size, reducing manufacturing cost.

Athlon II X2 uses AM3 socket, but is also backwards compatible with certified AM2+ motherboards. When installed on an AM3 motherboard it supports DDR3 memories, but if you put it on an AM2+ board it will work with DDR2 modules.

Athlon II X2 main features include:

• Two processing cores
• 64 KB instruction L1 memory cache and 64 KB data L1 memory cache for each core
• 512 KB or 1 MB L2 memory cache for each core
• HyperTransport (HT) bus running at 2 GHz (8 GB/s). This clock may also be referred as “4,000 MHz.”
• Socket AM3
• Dual channel configuration (you need to install an even number of memory modules to use this feature).
• SSE4a instruction set (which is not the same thing as SSE4 from Intel).

In the table below we list all the Athlon II X2 models released to date. TDP means Thermal Design Power and indicates the thermal dissipation of the CPU, i.e., the CPU cooler must be capable of dissipating at least this amount of heat.