AMD's Kabini: Jaguar And GCN Come Together In A 15 W APU showed us what the company's Jaguar and GCN architectures could accomplish between 4 and 25 W TDPs. But, on the desktop, AMD isn't quite ready to make the leap to a next-gen design. It just introduced its desktop-oriented Richland APUs, which aren't really new at all. Rather, you can think of them as power-optimized Trinity parts, sporting the same Piledriver-based x86 cores and VLIW4 graphics configuration. Moreover, Richland-based APUs have been available to mobile device makers for months. The only real revelation is that we're getting this update in the desktop and low-voltage mobile spaces now.
| Model | Radeon | Package | TDP | CPU Cores | Base/Max CPU Clock | L2 Cache | Radeon Cores | Base GPU Clock |
|---|---|---|---|---|---|---|---|---|
| A-Series Low-Voltage and Ultra Low-Voltage APUs | ||||||||
| A10-5745M | HD 8610G | FP2 | 25 W | 4 | 2.1/2.9 GHz | 4 MB | 384 | 533 MHz |
| A8-5545M | HD 8510G | FP2 | 19 W | 4 | 1.7/2.7 GHz | 4 MB | 384 | 450 MHz |
| A6-5345M | HD 8410G | FP2 | 17 W | 2 | 2.2/2.8 GHz | 1 MB | 192 | 450 MHz |
| A4-5145M | HD 8310G | FP2 | 17 W | 2 | 2.0/2.6 GHz | 1 MB | 128 | 424 MHz |
In the table above, we see the new mobile-oriented options spanning 17 to 25 W TDPs. Richland isn’t much different from Trinity, but it's more efficient thanks to specific Turbo Core optimizations that include a greater number of P-states to facilitate more granular power and performance levels.
| Model | Radeon | TDP | CPU Cores | Base/Max CPU Clock | Total Cache | Radeon Cores | GPU Clock | Unlock | Price |
|---|---|---|---|---|---|---|---|---|---|
| A10-6800K | HD 8670D | 100 W | 4 | 4.1/4.4 GHz | 4 MB | 384 | 844 MHz | Yes | $149 |
| A10-6700 | HD 8670D | 65 W | 4 | 3.7/4.3 GHz | 4 MB | 384 | 844 MHz | No | $149 |
| A8-6600K | HD 8570D | 100 W | 4 | 3.9/4.2 GHz | 4 MB | 256 | 844 MHz | Yes | $119 |
| A8-6500 | HD 8570D | 65 W | 4 | 3.5/4.1 GHz | 4 MB | 256 | 800 MHz | No | $119 |
| A6-6400K | HD 8470D | 65 W | 2 | 3.9/4.1 GHz | 1 MB | 192 | 800 MHz | Yes | $77 |
And then we have the desktop-specific Richland parts. The very fastest model enjoys a 300 MHz base clock rate bump compared to the A10-5800K, along with official support for 2133 MT/s DDR3 memory (the other SKUs top out at 1866 MT/s memory). Also, its GPU is 44 MHz faster than the prior-gen version. And yet it fits within the same 100 W TDP.
On the other hand, the A10-6700 looks a lot like the -5800K, aside from a 100 MHz-lower base clock, a 100 MHz-higher Turbo Core ceiling, and a slightly quicker GPU. That one drops to a 65 W thermal limit.
Like the Trinity-based APUs before them, these Richland designs plug into a Socket FM2 interface. A BIOS update should be all that you need for compatibility with existing A55, A75, and A85 platforms.
And what about those shiny new Radeon model numbers? That's marketing being bad. We were already dealing with Radeon HD 7000-series naming on APUs, which was confusing because AMD's desktop 7000-series GPUs are commonly associated with the GCN architecture. Now we have 8000-series nomenclature. And yet, we're still working with the VLIW4 configuration that was around back when AMD was shipping Radeon HD 6900-series cards. Architecturally, the only difference between Richland's Radeon HD 8000 graphics and Trinity's Radeon HD 7000 graphics is the name.
Again, the top-end A10-6800K gets 2133 MT/s memory support, which is particularly meaningful for its on-die graphics engine given a lack of shared L3 cache. The theoretical 34 GB/s of DDR3 bandwidth should go a long way to improve frame rates in the games we'll be testing. With that said, let's move on to why we aren't able to test Richland's Dual Graphics feature today...
AMD’s Dual Graphics technology, once referred to as Hybrid CrossFire, allows the APU to work cooperatively with a discrete graphics card to deliver higher game frame rates than either component flying solo. At first glance, this seems like a great way to extract value, offering an upgrade path not available on any competing platform.
Unfortunately, there are limitations. First, this is a software-based capability that only works with DirectX 10 and 11 game engines. Second, the APU is quickly outclassed by most discrete cards. So it really only works with Radeon HD 6450, 6570, and 6670 boards, maintaining balance between the two parts.
We've long since wanted to dig deeper into Dual Graphics; after all, as you can see in the screen capture above, AMD claims it serves up a serious performance increase. But in our subjective experience, this feature does not necessarily appear to yield smoother game play. For the company's Richland introduction, we were excited to finally test Dual Graphics using our FCAT tools, capturing the raw display output and analyzing the stream to determine if frames were being dropped entirely or rendered in a series of full and tiny (runt) frames.
Unfortunately, our video-based analysis turned up an unexpected issue that prevents us from reporting the performance of Dual Graphics. Intermittently, we'd see a frame rendered, followed by a piece of the following frame, a piece of the original frame, and the rest of the following frame. This artifact is accompanied by a tear across the screen as Dual Graphics puts the two frames together.
It's consequently impossible to run our FCAT analysis on the output, since the frame sequence can't be measured. Fraps-based testing in this case would clearly be inaccurate. So, it's better to hold off on trying to quantify the performance of Dual Graphics until AMD can provide a solution that composites the frames free from artifacts or tears. The company is aware of our findings and is working to address them. As of yet, though, we don't have an explanation of why this is happening.
