Closer Look at AMD A8-3870K Processor
In fact, AMD A8-3870K, which is the main character of our today’s review, is not really that new. It is the same Llano, just like other previously launched A8 products, which semiconductor die contains four computational Husky cores and a Sumo graphics core. By launching their A8-3870K, AMD’s major goal was not to increase the performance of Socket FM1 systems, but mostly to make them more attractive in terms of overclocking.
Therefore, the formal specifications of the new AMD A8-3870K look very similar to those of A8-3850:
It is, actually, all about raising the clock frequency of the computational cores by 100 MHz, which may be considered a barely noticeable upgrade in real life. Other than that, A8-3850 and A8-3870K are identical, so it is not surprising that the new APU is priced at the same $135 as its younger brother.
Obviously, any more dramatic increase of the Llano processors clock frequency could result in significant increase in their heat dissipation, which could go beyond the 100 W TDP set for this platform, even though these semiconductor dies are manufactured using quite contemporary 32 nm process. Therefore, AMD doesn’t have any means of increasing the computational performance of their APU. There is no dramatic increase in the clock frequencies of the existing Socket FM1 processors, and this situation will most likely continue until the next-generation Trinity products on Piledriver microarchitecture come out. K10 microarchitecture, which has been minimal modified on transition to Llano has completely exhausted its potential by now.
The major difference between the Llano and Propus computational cores is the different size of L2 cache-memory. Each A8-3870K core has 1 MB of L2 cache. Other than that, A8-3870K is very much like Athlon II 640. The difference in pure computational performance of these two processors is no more than 5-7% (in favor of A8-3870K) and results from twice as much cache-memory and a number of minor cosmetic improvements in Husky core: larger internal buffers and an individual unit for integer division operations.
It is much more interesting to take a closer look at the Sumo graphics core integrated into A8-3870K, which is implemented as Radeon HD 6550D graphics accelerator.
The graphics core in A8-3870K features 400 processors with VLIW5 microarchitecture. Since the clock frequency of this core is set at 600 MHz, the semiconductor die integrated into the processor is, in fact, the analogue of Radeon HD 5570 graphics card. However, it has no graphics memory of its own and uses part of the system memory for its needs.