CPU by stefan @ 2012-04-30
The Black Edition A8-3870K APU from AMD is aimed at the mainstream market and offers enough performance for occasional gaming at lower resolutions, other multimedia activities or office work, this without the need to buy a dedicated video card. Thanks to the unlocked multiplier, overclocking becomes much easier than before and the performance gains after this operation are quite surprising.
At first I would like to thank AMD for sending a sample of their A8-3870K Black Edition APU for testing and reviewing.
AMD (NYSE: AMD) is a semiconductor design innovator leading the next era of vivid digital experiences with its ground-breaking AMD Fusion Accelerated Processing Units (APUs). AMD’s graphics and computing technologies power a variety of solutions including PCs, game consoles and the servers that drive the Internet and businesses.
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With the more recent AMD A8-3870K APU, we will go back again and look at the AMD Lynx desktop platform, aimed mainly at budget conscious people, on 32nm. These APUs have a different IGP compared to the A6-3650 we have tested in the past, with 400 Radeon Cores vs 320 and a higher running frequency of 600MHz. The list of technical specifications for the Radeon HD 6550D GPU and a comparison with the Radeon HD 6530D can be found in the following table:
The A-Series APUs have a new socket, FM1 and are not compatible with the previous AM2 or AM3; however, the coolers that we have used on the older AMD sockets can be successfully used with the FM1 too; the APUs are supported by the A55 and A75 Fusion Controller Hubs, the later being more feature rich:
From the APU die Architecture photo, we can see that the IGP are takes quite a lot of space:
On the market, the A-Series APUs are positioned on different price levels and a small table with feature differences can be found on AMDs’ website. The A-Series can be also found with 3 or even 2-core variants; the 2-core APUs also have much less L2 cache, only 160 Radeon cores for the IGP, but the clock speeds are kept from the more expensive models; also, the cheapest models from the series have lower officially supported memory speeds, only 1600MHz. The A8-3870K is not the only unlocked (Black Edition variant), but we can also find one more in the A6 series, named A6-3670K, with lower GPU and CPU clocks:
The K version has its multiplier unlocked and is easier to overclock compared to the A6-3650; of course, we can also alter the reference clock which will also raise at the same time the IGP frequency, boosting performance even more. What remains to be seen from the tests that we will perform is if the system overall performance will increase significantly or not by using a higher clocked RAM.
Each APU can support single or dual-independent high resolution displays and provides exceptional multimedia capabilities with the 3rd generation of the Unified Video Decoder (UVD3) hardware decode support for H.264, VC-1, MPEG2, WMV, DivX, MVC and Adobe Flash.
As the last time, A8-3870K sample was shipped inside a small plastic box:
The CPU HSF holds information like serial number, batch number:
By looking on the bottom of the CPU, we can observe the pin design placement:
CPU: AMD A8-3870K Black Edition APU
CPU Cooler: Xigmatek Aegir
Motherboard: ECS A75F-A
RAM: Exceleram EP3001A PC3-10666 2x2GB
Video: IGP
Power Supply: Nexus RX-1.1K Gold
HDD: Seagate Barracuda 320GB 7200.10
With the help of AIDA64 utility, we could extract some more information regarding the Fusion platform components:
Here are the reports gathered with the latest version of CPU-Z, with the APU at stock speed:
With the voltage upped at 1.49V inside the UEFI interface, the APU could be overclocked up to 3742MHz, fully stable in Prime95 for an hour:
With the APU base clock modified at 110Mhz, the IGP frequency has been also raised to 680MHz; inside the motherboards' UEFI, we have had raised the frequency even more, till we have reached 720MHz:
For each chart:
Run 1: APU Stock + Mem. 1333MHz 9-9-9-24
Run 2: APU Stock + Mem. 1600MHz 9-9-9-24
Run 3: APU 3510MHz + IGP OC 702MHz + Mem. 1866MHz 9-9-9-24
Run 4: APU 3740MHz + IGP OC 720MHz + Mem. 1760MHz 9-9-9-24
As we have seen from the benchmarks, the newer A8-3870K APU from AMD seems to have about the same behavior when running memory at different speeds, like the previously tested A6-3650. The IGP performance increases quite lot when we compare the performance at 1600MHz or 1866MHz to the one we have obtained at 1333MHz. When we ran the tests at 1866MHz, the ECS board also overclocks the system bus at about 117MHz, so the resulting CPU clock is 3510MHz as opposed to 3GHz stock.
At about 1.496V for the CPU (1.49V set inside the UEFI interface), we were able to overclock the APU at a stable frequency of 3742MHz. We were able to overclock the IGP even further, to 720MHz, with the options offered inside the BIOS interface, this without increasing the NB voltage; the system memory was running at 1760MHz, a lower frequency that we had in the third run, with the memory at 1866MHz.
What is interesting to see is that even if we had higher CPU and IGP clocks in the 4th run, we weren’t able to get higher scores in the 3D applications compared to the 3rd run, when the memory was running at a higher frequency; however, in the productivity benchmarks like PCMark or in the SuperPi, Wprime runs, the score was noticeably higher.
The AMD Black Edition A8-3870K APU can be found in online stores for about 110 Euros, a decent price considering what is offered and the possibilities of overclocking. When buying such an APU, make sure you will also get a motherboard that supports modifying the frequencies, otherwise you won’t be able to enjoy the “K” unlocked features this product comes with.
I would like to thank again to AMD for making this review possible!