In June 2011, AMD launched the first line of Llano-based APUs (accelerated processor devices) of the A-series, which combined the K10 architecture with the Radeon GPU in one chip. But, unfortunately for those who would like to take advantage of the new product, its first launch with components codenamed Husky was aimed at laptop manufacturers and PC manufacturers. Thus, everyone who wanted to create their own personal computer based on Llano had to wait in line to gain access to new AMD processors. With the official launch of the desktop versions of the Llano A Series APU, code-named Lynx, that expectation is over.
AMD A8-3850: architecture overview
Like the low-power Brazos-based E-Series accelerated processors released by AMD in February 2011, the Lynx architecture marked a shift in the manufacturer’s strategic direction towards a more integrated approach. The company said the A-Series is the first line of processors that, along with a 4-core CPU, offers an integrated graphics chip in the hope that the market will put up with low-performance hybrid chips that end up in offices and budget PCs. AMD began this revolution with the release of 4 APUs related to the A8 and A6 series. They differed both in clock frequency and in-built graphics processing devices. The A8 core pair has 400 stream processors for the Radeon HD 6550D graphics chip, and the A6 has 320 in the HD 6530D. At the same time, the first APU is faster than the second, because it has a higher core frequency equal to 600 MHz against 443.
The line is further subdivided into models with different clock speeds. Two quad-core accelerated processors of the upper price range of the A8 and A6 series, AMD A8-3850 and A6-3650 APUs, use 2.9 GHz and 2.6 GHz, respectively (although these values decrease in standby mode due to Cool'n'Quiet ), and differ in quite impressive power consumption equal to 100 watts.
The two junior representatives of the line, A6-3600 and A8-3800, also support Turbo Core technology. This means that their speed changes dynamically depending on the requirements for them. A8-3800 uses a clock frequency of 2.4 GHz, increasing it to 2.9 GHz with Turbo Core turned on, and A6-3600 - by 2.1 GHz, bringing them to 2.4. Both of these hybrid processor devices consume much less power - only 65 watts.
The cores that provide such a floating frequency are based on a design with the pretty pretentious name Stars. In reality, this is simply an improved 32nm version of the 45nm Phenom II. This means that the CPU in the AMD chip is still based on the outdated K10 architecture, which in the past did not compete well with Intel Core. However, the accelerated Lynx processor offers a feature different from competing Intel chips. This is the speed of interaction with RAM. Each of the A series models supports DDR3 operating at a frequency of up to 1866 MHz, and not 1333 MHz, as Intel's budget chips require. Since this memory is distributed between the central and graphic processor devices, it can provide an easy increase in graphics performance through the use of faster RAM.
Llano architecture also includes a dedicated unified UVD video decoder, which allows unloading CPUs and GPUs when playing videos without support for DirectX video acceleration.
In addition to the release of the A8 and A6, AMD offers a pair of chipsets for motherboards called A55 and A75. Each of them supports RAID and hard drives larger than 2.2 TB, but the premium A75 chipset also allows you to have 4 USB 3 ports and 6 SATA connectors, operating at 6 Gb / s.
In the graphic part of the APU, 400 stream processors perform operations at a frequency of 600 MHz and are divided into 5 SIMD blocks with a common register and tessellation block, as well as 20 texture processing units and 8 ROPs.
Architecture features
The high-end AMD A8-3850 processor costing $ 135 is in direct competition with the dual-core i3-2100. The chip includes 4 Star cores that operate at a frequency of 2.9 GHz. They are made using 32-nanometer technology, which provides a 6 percent increase in the useful area of the crystal compared to the 45-nm process of the previous generation Athlon II. Each core is allocated 128 KB of cache level 1 and 1 MB L2. The third, larger tier of the APU is missing.
For series A, a 905-pin FM1 AMD A8-3850 connector was specially created, since there was a need to output video from the processor to the DVI, VGA and HDMI connectors of the motherboard. Of course, there can be no question of any backward compatibility of previous AMD CPU models. Despite changing socket specifications for heat dissipation have not changed. All existing coolers should still be compatible, as they correspond to the calculated thermal power of the chip.
In addition, under the integrated thermal diffuser is a Radeon HD 6550D graphics processor running at 600 MHz. This looks rather weak compared to the 850 MHz used by the HD Graphics 2000 in the i3-2100. However, AMD GPUs are equipped with a huge number of stream processors (400) and texture units (20) compared to Intel's 6 small executive modules. The A8-3850 also surpasses the i3-2100 in terms of capabilities, since the first chip provides full DirectX 11 support, while the second is only compatible with version 10.
The AMD A8-3850 APU features are supported by a number of unique features, including Dual Graphics technology. Like CrossFire technology to provide additional power, it allows the integrated GPU to combine with other compatible discrete graphics cards of the manufacturer. This function is activated in ASRock BIOS by default, so just insert a video card and the motherboard with AMD A8-3850 drivers will do the rest. There are some limitations. The technology works in games that support DirectX 11 and 10. With DX9, Dual Graphics functions, but in this case the performance is not optimal. With Llano architecture, the manufacturing company also demonstrated for the first time asynchronous multiprocessing rendering, which allows you to distribute various workloads between the central and graphic processors. Compatibility is supported only with low-performance AMD GPUs, including HD 6670 1 GB, HD 6570 1 GB, HD 6450 512 MB and HD 6350 512 MB.
Overclocking AMD A8-3850
As you can see, the Lynx architecture is not aimed at high-performance enthusiasts. As a result of this, the overclocking capabilities of the AMD A8-3850 processor are also limited. For example, users were delighted to learn that the design of the Intel integrated generator was copied. This means that all clock frequencies throughout the board are connected to each other. As you can see in Sandy Bridge systems, this setting, in fact, makes it impossible to overclock through the base frequencies (or reference, if we talk about APU Llano), since their increase by more than 5% can lead to instability in the SATA and USB subsystems . Given the fact that the A series processors have a CPU multiplier blocked, there is little hope that the AMD A8-3850 will exceed 2.9 GHz based on 100 MHz reference clock pulses and a 29x multiplier.
But users were intrigued by the fact that the ASRock A75 Pro4 motherboard, which they used for testing, allowed to increase the multiplier to 36x, which led to a total frequency of 3.6 GHz. However, despite the CPU-Z reporting the achievement of the above value, in fact, the multiplier has not changed. The test results were identical to the performance at 2.9 GHz. The attempts to overclock the AMD A8-3850 turned out to be practically fruitless, since users managed to achieve only an increase of 5 MHz, which led to an increase in the processor frequency to 3.4 GHz, and GPU - to 630 MHz. According to the manufacturer, this is due to the fact that some of the motherboards have the ability to block SATA and USB to allow more overclocking. The same source claims that some boards have invisible dividers that turn on for SATA and USB at certain reference clock frequencies. This may mean, for example, that 133 MHz leads to stable overclocking of the AMD A8-3850 processor, while at 120 MHz this cannot be achieved simply because a larger clock cycle initiates the use of a higher SATA / USB divider.
According to user reviews, this information for overclocking was not very useful, since the motherboard resolutely refused to boot at any reference frequency above 105 MHz.
Cinebench r11.5
This test uses Maxon's Cinema 4D to render a very complex photorealistic scene with reflections, ambient light, and procedural shaders that significantly load the CPU. Since it involves real-world objects found in films such as Spider-Man and Star Wars, the Cinebench R11.5 can be seen as a test of the real environment. According to user reviews, the processor scored 3.33 points at 2.9 GHz and 3.51 points at 3.04 GHz. The competitor Core i3-2100 scored 3 points.
WPrime
This is a multi-threaded math test with the counterintuitive use of square roots rather than primes. The standard test uses a set of 32 million numbers and calculates the square roots of each of them with a recursive call to the Newton method as an evaluation function. WPrime scales very well across multiple cores of a central processing unit and can load them 100% fully. The result of the calculation is expressed by the amount of time spent finding the square root of the entire set of 32 million numbers. The lower the score, the higher the performance. According to user reviews, the result of AMD A8-3850 is 14.443 s and 13.635 s (at 2.9 and 3.04 GHz). Core i3-2100 takes longer. For all calculations, the Intel processor spends 18,090 s.
Left 4 Dead 2
According to user reviews, launching this game in the resolution of 1280 x 720, 0x AA, 16x AF and high image quality settings allows you to achieve a minimum of 54 and an average of 76 fps at 2.9 GHz clock speed and, respectively, 60 and 80 fps overclocking to 3.04 GHz. The Core i3-2100 processor provides a frame rate of 13 and 22 fps.
Call of Duty: Black Ops
According to user reviews, the game was tested with maximum detail set in the game menu. Since the highest frame rate is by default limited to 91 fps, it had to be increased to 250 fps in the configuration file. The launch of a 90-second fragment of a multiplayer game played through an excellent built-in player, with settings similar to the previous test, showed the lowest screen refresh rate of 30 fps, and its average value was 54 fps. For an overclocked processor, these figures increased to 33 and 60 fps, respectively. The competing Intel Core processor showed unacceptable 11 and 20 fps.
Power consumption
For all performance tests conducted by processor users, all energy-saving technologies were turned off so that you can get adequate results and present the best performance, despite the fact that technologies such as Intel SpeedStep require microseconds to start, which in some cases can to tell. However, to evaluate the characteristics of the AMD A8-3850 processor in the field of power consumption, all the functionality was fully utilized so that using an external wattmeter it was possible to determine the actual power consumption, so the results represent the total power of the system, and not the power consumption of the CPU itself. Separate metering of the consumption of any individual PC component is almost impossible.
According to user reviews, in standby mode, when there is nothing on the PC screen other than the Windows 7 desktop with Aero activated, the total consumption of the system based on AMD A8-3850 Quadcore is 47 W, and Intel Core i3-2100 - 40 W. An analysis of the energy efficiency of the processor when both the CPU and the GPU are under load for the tested model gave a result of 92 watts. The competitor this indicator was much less - only 66 watts.
Performance analysis
To compare the test results of the AMD A8-3850, we used the Core i3-2100 processor, which was sold at the same price, as well as comparable motherboards chosen so that the total cost of the system for the two test benches was approximately the same. The performance test for the evaluated model began well, since its evaluation in Cinebench 11.5 (3.33) by 0.33 was ahead of the competitor Intel. A similar situation arose in the WPrime 32M test. The A8-3850 processor with a time of 14.443 s was far ahead of the competitor, the result of which was 18.090 s. The reason for this is twice as many cores. It is in these tests that additional power gives the maximum advantage.
More stringent verification in the form of processing multimedia files takes advantage of multiprocessor computing, but also rewards processors that execute more instructions per cycle. The i3-2100 chip dominates in this area because the Sandy Bridge architecture is capable of processing much more data than the aging K10 architecture.
The image editing test rated the AMD A8-3850 2 90 GHz at 888, and the i3-2100 at 1331 points, which was 49% better. The same thing happened in other tests, while the A8-3850 lagged 28% in video encoding, which usually rewards processors with additional cores. The total score of A8-3850 was 1059 points, which significantly lags behind 1476 points for the Intel processor.
However, the main advantage of the APU Llano, according to user reviews, is its improved performance in 3D games. Could it become the basis for a cheap gaming PC? Or are entry-level GPUs doomed? The answer to both questions will be a decisive “Yes!”
With a screen resolution of 1280 x 720 pixels with 0x AA, the AMD A8-3850 APU processor in L4D2 provides a minimum frame rate of 54 fps with all the settings set to high. This is an excellent result, which means that now, finally, it has become possible to build a home theater system that allows you to play in 720p resolution without having to install a separate graphics card. For comparison, the minimum frame rate of the i3-2100 processor at 13 fps with the same settings practically does not allow playing. In the game L4D2 A8-3850 also works well with higher image clarity. At a resolution of 1680 x 1050 pixels, the APU provides a minimum frame rate of 33 fps, which allows you to play comfortably even during a zombie invasion. This makes the Llano-based system truly competitive if you choose graphically less demanding games in a standard 22-inch display resolution . The game COD: Black Ops also shows acceptable results in a resolution of 1280 x 720 without AA, although the processor is no longer able to cope with a large number of pixels.
A more subtle difference between the chips of competing companies can be seen in the image quality when evaluating 3D performance. The Intel i3-2100 GPU in games did not cope with some of the soft shadows that can be seen in the AMD system, despite the fact that all the game settings are the same. The loss of these shadows immediately catches the eye as they add depth and realism to the gaming environment.
DRAM speed
The technical characteristics of the AMD A8-3850 processor were evaluated using DDR3 memory with an operating frequency of 1333 MHz. Thanks to this, the comparison of the results becomes fair. Nevertheless, it is interesting to check how much the performance of the A8-3850 will increase from the use of faster RAM. Moreover, the graphics processor shares RAM with the central one. Using a faster storage device should be comparable to overclocking in a discrete graphics card.
This was confirmed in practice. According to user reviews, increasing the DDR3 frequency to 1.6 GHz significantly improved 3D performance. The minimum frame rate increased by 6 fps with a resolution of 1680 x 1050 pixels in L4D 2 and 3 fps in Black Ops, which slightly improved its quality. Interestingly, an increase in the frequency of RAM to 1600 MHz affected more than the meager overclocking of the processor.
Conclusion
It is impossible to resist the positive characteristics of the AMD A8-3850, since with its appearance, fully integrated graphics finally became available, capable of providing reasonable performance. APU has proven its worth in gaming tests at low and medium resolutions, even if all other settings are set to maximum. This makes AMD A-Series processors a welcome purchase for those who need a low-power media center or budget gaming station to pair with a small-sized monitor. An interesting solution is the asymmetric CrossFire, which allows you to achieve higher performance on an inexpensive hybrid processor with a discrete base-level graphics card, although limiting it to DX10 / 11 games is a significant limiting factor. The A8-3850 seems to have made most of the base segment of the GPU market redundant. And this is the result that users were most pleased with.
Unfortunately, not everything is so rosy. As the low performance of the AMD A8-3850 processor in multimedia tests shows, the model lags behind the Intel і3-2100 chip at a similar price. Obviously, this will be a problem when editing images or encoding a video. Nevertheless, according to users, the compromise between improved graphics performance in exchange for moderately worse media performance in most cases is justified, especially if such systems become widespread in the future.
Customers who need an inexpensive PC, just an office computer or a home theater, capable of becoming a game station for a while if necessary, will find the A8-3850 ideal, since the processor will cost much less than a system based on the i3-2100 with a discrete GPU. The AMD chipset has more than enough power to provide high-speed performance and has the advantages of a discrete graphics processor, which are enough to support the necessary 3D performance.