What's A Stepping?
As already described, a processor stepping is simply a new hardware revision, but it does not involve significant changes or even a redesign of the micro architecture. There can be feature enhancements or other improvements, but microchip manufacturers mainly look at their products to fix technical bugs - these are referred to as errata and most are typically published by AMD and Intel. A so-called die shrink - e.g. when transitioning an existing product from a 90-nm process to a smaller 65-nm process - isn't referred to as a stepping. However, shrinking the device can be also be used to apply modifications, such as adding larger cache memory capacities or enhanced instruction sets.
While a new stepping has been sold using the same product and model numbers by AMD and Intel in the past, a die shrink can involve sufficient modifications to justify creating new model numbers for the devices. Intel's Core 2 Duo is a good example. The device's 45-nm versions with 6 and 3 MB L2 cache are called the E8000 series, while the E6000 with 4 or 2 MB L2 cache is based on the 65-nm process. In contrast, AMD has kept the model number 5000 for all 90-nm and 65-nm versions.
Steppings are not only a good opportunity to fix known issues and to introduce improvements on the feature side, but they are used to deploy what the chipmaker has learned over time in its fabs. The production process can often be improved by applying minimal changes, or it can include changing an entire part of the manufacturing process. Adjustments in manufacturing can lead to improved yield rates. They can also eliminate - or at least diffuse - so-called hot spots or allow for the manufacturer to make a given process more environmentally friendly. Clearly, new steppings do not always have to lead to better features or noticeable improvements, while business reasons and other considerations are always part of the equation.
CPU-Z is a useful tool to learn more about processor revisions and stepping histories. Windows typically doesn't disclose this information, as it is of little relevance for the majority of PC users.
AMD Socket AM2 Steppings And Model Numbers
AMD has had two major steppings for both the 90-nm and the 65-nm versions of the Athlon 64 X2 on socket AM2. When it was first introduced, there was the 90-nm F2 stepping, which was followed by the 90-nm F1. After the launch of AMD's 65-nm Athlon 64 X2 processors AMD followed up with its G2 stepping a few months later.
|Processor||AMD Athlon 64 X2 Dual-Core|
|Operating Mode 32 Bit||Yes|
|Operating Mode 64 Bit||Yes|
|Core Speed (MHz)||2600|
|System Bus Speed (MHz)||2000|
|Max Temps (C)||55-68'C||55-72||55-70||55-72|
|Wattage||65 W||89 W||65 W|
|L1 Cache Size (kB)||128|
|L1 Cache Count||2|
|L2 Cache Size (kB)||512|
|L2 Cache Count||2|
|L3 Cache Size (kB)||0|
|CMOS||65nm SOI||90nm SOI|