As noted earlier, and in our Radeon HD 7970/7950 launch coverage, AMD hasn't yet ironed out the kinks with hardware acceleration in its newest architecture. So, it wasn't much of a surprise that SimHD wouldn't work with our 7900-series boards. Instead, we dropped in a Radeon HD 5870, which is currently compatible. Its 1600 shaders operating at 850 MHz still deliver respectable performance in today's games, so we're curious to see what this now fairly-mainstream card can do in a compute workload.
In this first test result set, we ran all of the post-processing on the CPU, with hardware acceleration disabled. Low, average, and high CPU utilization values are shown (in percent) to indicate the range of processor resources consumed by SimHD’s upscaling. Both mobile platforms are roughly comparable, though AMD's average utilization is likely lower as a result of its four physical cores.
The desktop numbers are more interesting. Yes, the overall utilization is roughly two to three times less on the desktop, which is telling since both mobile processors sport 35 W TDPs compared to the 100 and 125 W APU and FX CPU.
But also, notice how there is very little difference between the A8 APU and the higher-end FX chip. Although the FX has more transistors dedicated to general-purpose processing, a nice large shared L3 cache, and higher clock rates, it isn't able to demonstrate an advantage over the more mainstream A8. Clearly, there's some other bottleneck in play.
With GPU acceleration enabled, the APU-driven notebook starts to exhibit a performance advantage over the CPU-only model, though perhaps not to the extent we were expecting. Any advantage is notable when you're talking about a battery-powered piece of hardware, however, the more significant gains start cropping up when you have the resources of a desktop-class configuration to throw at the upscaler.
Clearly, the biggest gains are available to those who use more potent discrete graphics on a platform with a fast CPU to accelerate demanding workloads. Testing the same graphics card next to AMD's A8 doesn't yield as compelling of a gain, likely due to a processor bottleneck.
When it comes to balancing out performance for your dollar, though, the A8 leaning on its integrated Radeon HD 6550D graphics engine is the real winner here. Consider that the A8-3850 sells for $135. AMD's idea here has to be one of putting two technologies together at an affordable price, where in the past you would have needed separate entry-level CPUs and graphics card to achieve the same thing (and the Radeon HD 5870 wasn't a cheap board, either).
- What Does Heterogeneous Computing Really Promise?
- DirectCompute And OpenCL: The Not-So-Secret Sauces
- Test Setup And Benchmarks
- Tom's Hardware Q&A With ArcSoft
- Tom's Hardware Q&A With MotionDSP
- Tom's Hardware Q&A With MotionDSP, Continued
- Benchmark Results: ArcSoft Total Media Theatre SimHD
- Benchmark Results: vReveal On The FX-8150 And Radeon HD 5870
- Benchmark Results: vReveal On The FX-8150 And Radeon HD 7970
- Benchmark Results: vReveal On The A8-3850 With Discrete Graphics
- Benchmark Results: vReveal On The A8-3850's Radeon HD 6550D
- Mobile Platform Results And Wrap-Up