The new A-Series desktop processors round out AMD's Fusion CPU family, and make AMD the second processor manufacturer this year to combine a standard desktop chip with an embedded graphics processor on a single piece of silicon. Intel was the first, with its second-generation Core series (formerly known as Sandy Bridge) that debuted in January. While AMD's approach is generally not as fast as Intel's in terms of traditional processing power, it has drawn on the resources of its Radeon graphics business to provide the A8-3850 chip with impressive 3D performance for its price of $135. We can recommend AMD's new chip as a low-cost gaming platform and for multithreaded applications, but many users will still get faster general performance from an equivalent Intel chip.
AMD has not competed well with Intel in recent years, in part due to Intel's relentless pursuit of ever-more-efficient CPU manufacturing processes. In combination with the fact that Intel owns its own manufacturing facilities, compared with AMD which has to use other companies' plants, the result has been that Intel's CPUs have maintained a dollar-for-dollar performance lead over AMD's since Intel first introduced its Core 2 Duo chip family in mid-2007.
Aside from that manufacturing competition, this latest generation of CPUs represents a major step in what's been a slow shift in the way we think about computing. Traditionally, CPUs handle application processing duties, and GPUs (graphics processing units) were meant for gaming and dedicated video processing programs. Since Intel's Core CPUs launched earlier this year, and really as early as the 2008 debut of Nvidia's CUDA technology, those lines have blurred. Now, applications ranging from Adobe Creative Suite 5 and Flash 10.1 to Windows 7, Internet Explorer 9, and Firefox 4.0 can use the graphics processor to speed up performance, particularly when it comes to rendering visual elements. Windows' translucent Aero visual theme, for example, supports GPU acceleration.
As Intel did with Sandy Bridge, AMD has rolled a graphics chip directly into its new A-Series processor designs. The A8-3850, reviewed here, offers the equivalent of four Phenom II CPU cores combined with an AMD Radeon HD 6550 graphics core. The result is a chip designed to handle the demands of different processing workloads quickly and efficiently.
|AMD A8-3850||Intel Core i3 2105|
|Number of physical cores/processing threads||4/4||2/4|
|Maximum CPU clock speed||2.9GHz||3.1GHz|
|Maximum memory speed||1,866MHz DDR3 SDRAM||1,333MHz DDR3 SDRAM|
|Embedded graphics core||AMD Radeon HD 6550||Intel HD Graphics 3000|
|Graphics core clock speed||600MHz||850MHz|
AMD is sticking with very mainstream price points and clock speeds for its new CPU. The A8-3850 is the most high-end chip of the four announced. A $119, the A6-3650 has a clock speed of 2.6GHz, with A8-3800 and A6-3600 variants filling in the price bands in between. The latter two chips use AMD's Turbo Core technology, which dynamically ramps up the core CPU clock speed according to the workload, similar to Intel's Turbo Boost feature. Unlike Turbo Boost, Turbo Core provides only a marginal speed increase to the chips that use it, and the bump applies to all four cores simultaneously. Intel's Turbo Boost has a broader range of clock speeds, and can apply a speed boost to individual cores as workloads demand.
Intel's dual-core Core i3 2105 CPU is the closest competitor to the fixed-frequency A8-3850 in terms of price. Although the Intel chip has a faster core clock speed, it has only two physical processing cores. Intel's Hyper-Threading technology virtualizes an additional processing thread on each core, and in that way the Core i3 2105 mimics the behavior of a quad-core CPU. In contrast, the A8-3850, and all of AMD's new desktop chips, each have four physical processing cores.
|Rendering multiple CPUs||Rendering single CPU|
As you can see from our application performance tests, AMD's new A8-3850 isn't quite ready to compete with Intel on file conversion and other traditional multimedia tasks. The Core i3 2105 outperformed the A8-3850 in almost every application test, including our Photoshop CS5 test, which uses filters that can benefit from GPU processing capabilities. We thought that if the AMD chip and its beefy graphics core had a shot it would be on that test, but it seems that's not the case.
Interestingly, for programs that are focused on multicore CPU processing, like our Cinebench test, the A83850 and its four native CPU cores will outperform Intel's simulated four-core chip. This makes for a rather complicated competitive landscape. Do you opt for a CPU with strong single-core performance, strong multicore performance, or strong GPU computing performance? No vendor can claim superiority across all three processing strategies, which means you must either pick based on the design of the applications you use most commonly, or look for a chip that offers the best all-around performance. With many programs still reliant on single-core processing speed, Intel seems like the safest choice. For gamers (as you'll see below) or users of multicore applications, we'd suggest AMD.
Also, note that you can see measurable performance gains from the AMD chip if you opt for 1,600MHz DDR3 RAM instead of 1,333MHz sticks. Even though the extra RAM speed doesn't allow the A8-3850 to overtake Intel, the 1,666MHz memory showed gains of 30 seconds in our Photoshop CS 5 test, and just under 15 seconds in our multimedia multitasking test. While we can't recommend the new AMD chip at this price if you need fast performance in digital media applications, we can at least say that using faster memory with the A8-3850 has real benefits. A quick scan of Newegg shows that 1,600MHz RAM will only cost about $5 more than equivalent 1,333MHz RAM, a relatively modest premium.
|1,440x900 (DirectX 10, 4x aa, very high)|
|1,600x1,080 (low detail)|
While AMD may lag behind Intel in certain kinds of application performance, the A8-3850's 3D graphics capabilities considerably improve the outlook for budget gaming desktops. Even at low resolution and image quality, Intel's HD Graphics 3000 core can't provide a playable Far Cry 2 experience. AMD's Radeon HD 6550, particularly with the faster memory, offers nearly three times the performance.
The A8-3850's advantage on the more demanding Metro 2033 is less dramatic, but still noticeable. Here the AMD chip offers marginally better performance in DirectX 10 mode than in DirectX 11. Intel's chip offers only DirectX 10 support, but even compared with the A8-3850's worst DirectX 11 frame rate, the Core i3 is still about 50 percent slower.
Between these two scores, with Far Cry 2 representing a very forgiving game, and Metro 2033 among the most demanding, we can say that while you would still enjoy a better gaming experience with a discrete graphics card, the AMD A8-3850 and its Radeon HD 6550 graphics core offer impressive PC gaming capabilities for the price. As AMD has done before, if you add a lower-end Radeon HD 6000-series card to a desktop with the A8-3850, the two will work together, in a sort of budget dual-graphics card mode. A more high-end graphics card won't receive a boost from the embedded CPU graphics core, but paired with a Radeon HD 6750, for example, AMD says the A8-3850 will provide roughly between 10 percent and 25 percent more performance than you'd see from the 6750 card by itself.
Due to the new architecture, AMD's new chips will require new motherboard chipsets as well. You'll find AMD's new A55 and A75 chipsets in motherboards from the usual third-party vendors. Our test board, an ASRock A75 Pro4, comes in on the higher end, but offers a modern assortment of ports, including four USB 3.0 inputs, five SATA III ports, and two PCI Express graphics card slots, the most we've seen on one motherboard. You also get HDMI, VGA, and DVI video outputs, and dual-monitor support. The motherboard also supports 6GBps SATA inputs.
The A55 variants have USB 2.0 jacks only, and support only SATA II storage devices. AMD's new platform can also support 3D Blu-ray playback. That might not be the most popular feature, but home-theater PC builders may appreciate it, and it's not a feature supported by Intel's second-gen Core platform.
|AMD A8-3850||Average watts per hour|
|Raw (annual kWh)||201.926322|
|Annual power consumption cost (@$0.1135/kWh)||$22.92|
Our power consumption comparison was thwarted somewhat by the fact that the Intel Z68 motherboard wouldn't work with our admittedly old 500-watt Antec Neo HE 500 power supply. To keep things equal, we tested both systems with a 1,000-watt PSU, but that much wattage is completely overkill for these CPUs, and the resulting power efficiency comparison was not representative of the power draw you'd see from desktops using these chips. With a more typical power supply, the AMD A8-3850 offered power efficiency that seemed to improve on that of older AMD chips with similar performance, like the 2.9GHz AMD Phenom II X4 810T CPU in the HP Pavilion P6720f. In any case, the A8-3850's power draw even in our unoptimized test bed was impressive. We'd expect a vendor-built system with a more efficient power supply and strategically selected power management features to offer even greater efficiency.
Budget gamers in particular should be excited about AMD's new family of APU desktop chips due to their strong 3D performance. We'd hoped to see faster graphics processing in Photoshop CS5 as well, but Intel's standard CPU performance superiority seems to give it the edge there and with programs that rely on more traditional CPU processing. If you regularly use a program designed to make use of multiple processing cores, the A8-3850 is a better choice. Regardless of situational hair-splitting, AMD's A8-3850 is robust enough to offer an acceptable computing experience, and its 3D processing power, both by itself and in conjunction with a lower-end Radeon graphics card, should make this chip popular, particularly among mainstream gamers.
Test system configurations:
AMD test bed
Windows 7 Home Premium 64-bit; 2.9GHz AMD A8-3850; ASRock A75 Pro4 motherboard; 8GB 1,600MHz DDR3 SDRAM/1,333MHz DDR3 SDRAM; 512MB ATI Radeon HD 6550 embedded; 500GB, 7,200rpm Western Digital SATA II hard drive
Intel test bed
Windows 7 Home Premium 64-bit; 3.1GHz Intel Core i3 2105; 8GB 1,333MHz DDR3 SDRAM; Intel DZZ68DB motherboard; 64MB Intel HD Graphics 2000 embedded; 500GB, 7,200rpm Western Digital SATA II hard drive