Tested Processor: A10-7850K
To carry out our today’s tests we’ve got a sample of the senior Kaveri-based APU with the model name of A10-7850K. Here are its specs in comparison with the flagship Richland-based model:
As you can see, the senior Kaveri model is more expensive than the A10-6800K but doesn’t offer much for that money. In fact, it is only superior in terms of GPU performance as its GPU features a new architecture and has more shader processors. On the other hand, the graphics performance of the A10-7850K is going to be limited by its memory bandwidth rather than its GPU. For example, the discrete card Radeon R7 250 has only 384 shader processors but comes with 73.6GB/s GDDR5 SDRAM. The A10-7850K will only have a peak memory bandwidth of 34.1 GB/s if equipped with dual-channel DDR3-2133.
The GPU is clocked at 720 MHz in 3D applications. In 2D mode the clock rate is dropped to 350 MHz to save power. It must be noted that the Richland’s graphics worked at higher clock rates, so the difference between the A10-7850K and A10-6800K in terms of theoretical performance is about 13% in favor of the newer APU: 737 vs. 648 gigaflops.
The x86 part is not going to ensure such performance benefits. The Steamroller microarchitecture doesn’t bring about a significant increase in the number of instructions executed per clock cycle whereas the clock rate of the A10-7850K is considerably lower compared to its predecessor.
AMD markets the new APU at the same price as junior Core i5 models, which seems to be too expensive. Perhaps we just don’t see some hidden benefits?
According to the CPU-Z utility, the fully loaded A10-7850K works at 3.7 GHz and 1.328 volts, which is comparable to the typical voltage of AMD’s earlier APUs. The Turbo Cache technology boosts the clock rate to 4.0 GHz when only one or two Steamroller modules are in use. It is good that AMD has implemented the frequency adjustment correctly in the Kaveri, so we didn’t observe any frequency drops below the baseline of 3.7 GHz during our tests as we had seen with the earlier products. When idle, the A10-7850K is clocked at 1.7 GHz using power-saving technologies. The APU-integrated North Bridge is clocked at a lower frequency than the APU itself. This frequency is 1.8 GHz for the A10-7850K.
The A10-7850K is shipped in AMD’s traditional black-and-red packaging. As is mentioned on the box, the APU is Black Edition, so its frequency multipliers are unlocked, letting you easily overclock both its x86 and graphics cores.
The APU is shipped together with a simple cooler that consists of an aluminum heatsink and a PWM-regulated 70mm fan AVC DESC0715B2U.
Unfortunately, this cooler is no good for serious loads. At the maximum speed of 4100 RPM it is rather noisy. And it cannot cope with the A10-7850K when the latter is overclocked.