AMD Athlon II X4 microprocessor family

ADX620WFK42GI / ADX620WFGIBOX, or model 620, was one of the first two processors in the Athlon II X4 family. The 620 was released together with model 630 on September 16. The Athlon II X4 620 had 7% lower frequency than the 630, and it was 23% cheaper. In fact, the 620 was the cheapest quad-core CPU on market during its introduction. In a related press release, AMD announced it as the "first sub-$100 quad-core CPU". The 620 and other Athlon II X4 processors have most of the features of more expensive Phenom II X4 models, but don't have level 3 cache. For example, Phenom II X4 810 and 910 run at the same frequency and have similar features as the 620, but the Phenoms include 4 MB and 6 MB L3 cache respectively. Large shared level 3 cache provides significant boost, in some cases by 20% or more, in applications that require high memory bandwidth.

Quad-core 635 is the third standard-power processor of the Athlon II X4 family. This CPU is clocked at 2.9 GHz, or 300 and 100 MHz higher than models 630 and 620 respectively. The Athlon II 635 processor was introduced in January 2010 along with dual-core 255 and triple-core 400 CPUs, and it has the same Thermal Design Power and other thermal and electrical characteristics as other standard-power quad-core Athlon IIs. The 635 is the last quad-core model that used original C2 core stepping. The next standard-power microprocessor with model number 640, released in May 2010, had newer C3 core revision.