Closer Look at Socket FM2 Refresh
AMD’s high-performance hybrid processors for desktop PCs form a separate and closed ecosystem. It was originally the Socket FM1 platform with Llano series APUs. Then there was the Socket FM2 platform with Trinity APUs that featured the more progressive Piledriver microarchitecture and faster VLIW4 graphics cores. The 2013 model year APUs of the Richland generation do not bring about any dramatic improvements over their predecessors but the good side is that the platform remains stable. Older mainboards for Trinity APUs with A85X, A75 and A55 chipsets are perfectly compatible with the Richland series after a BIOS update.
AMD has successfully kept its promise that Socket FM2 is a long-lasting design but the upcoming Kaveri series APUs, built out of computing and graphics cores with new architecture and supporting a shared address space for all types of cores, will call for a new socket and, consequently, for new chipsets. In other words, the Kaveri APUs won’t be compatible with the existing Socket FM2 mainboards, putting an end to the lifecycle of that platform.
The Richland doesn’t change anything in the Socket FM2 ecosystem, just as expected. Although AMD manufactures Kabini and Temash processors on 28nm technology, the Richland is based on a 32nm semiconductor die. The die itself is exactly like a Trinity die: 246 sq. mm and 1.3 billion transistors. That’s a clear indication of the lack of any design modifications.
Anyway, like their mobile counterparts, the new desktop Richland-based APUs are somewhat optimized in terms of the Turbo Core technology. Additional sensors installed on the APU die provide more accurate temperature data while the frequency adjustment algorithm has been modified to support more intermediary states. As a result, the clock rate changes more responsively depending on the APU's temperature while the APU's cores spend more time working in the Turbo mode.
It is questionable whether such changes are enough to regard the Richmond as a new APU generation, yet AMD has introduced a new series of model numbers for its new APU products. Although the Richland processors are identical to their Trinity counterparts and use Piledriver x86 cores with VLIW4 graphics cores, their model numbers are higher by 1000 and their graphics core is referred to as Radeon HD 8000D.
Comparing the specifications, the Richland APUs are about 300 MHz faster than their Trinity cousins in terms of the clock rates of their x86 cores. The graphics core frequency is higher by 40 to 84 MHz depending on the specific APU model. The number of Piledriver modules, the amount of cache memory and the number of shader processors in the graphics core have remained the same. The older Trinity-based A10, A8 and A6 APUs of the 5000 series and their 6000 series successors are very similar indeed. They even have the same overall structure of the model range which splits into two groups. The first group includes overclocker-friendly products with a TDP of 100 watts which have maximum x86 and graphics core frequencies and allow to overclock via the frequency multiplier. The second group includes 65-watt products which are somewhat slower but let you build rather economical computers. The Richland APUs are somewhat more expensive but they are supposed to add to rather than to replace the earlier Trinity APUs.
As a result, the new model names may be confusing, especially when it comes to the graphics core indexes. AMD doesn’t seem to be disturbed by the fact that its discrete graphics cores of the 7000 and 8000 series feature the GCN architecture whereas the graphics cores of the Trinity and Richland APUs are related to the Radeon HD 6900 in its design. As for the processors themselves, it is possible to use their model numbers within the A10, A8 and A6 series for making comparisons. Within each series, Richland-based APUs offer higher clock rates, so their higher model numbers do mean somewhat higher performance.
The performance benefits are not really high, though. They are going to amount to 5 to 7% in the majority of applications. Considering this, AMD has tried to ensure more speed by overclocking the memory controller, so the senior model A10-6800K is officially compatible with DDR3-2133 SDRAM. Well, this type of memory was supported by senior Trinity-based APU models as well, even though not officially, so it is hardly a serious innovation. Moreover, the rest of the Richland-based APUs do not support such fast system memory.