AMD Kaveri Performance
AMD Kaveri, new APU series based on latest Steamroller architecture and using GCN integrated graphics, has been shown extensively at CES. The move from 32 nm to 28 nm manufacturing process finally allows AMD to put more performance inside the same thermal envelope. While AMD initially expected to release it last year, they did not delay it too much and 95W A10-7850K and A10-7700K are already available for purchase for £130 and £115 respectively. A lower power 65W/45W A8-7600 APU is expected to become available later this quarter for £90 price. Kaveri is also AMD’s main push to introduce HSA (allowing iGPU to compute tasks it excels at) and hUMA (allowing iGPU and CPU to fully share the memory). So let’s look at what new AMD APUs bring to the table.
On the CPU side, there are architectural improvements, providing more performance per clock. However, due to the specific manufacturing process used for Kaveri, it cannot reach the same frequencies as its predecessor. The new frequency limit for the most powerful A10-7850K is 4 GHz. As a result, Kaveri’s CPU performance has barely improved. All currently announced Kaveri APUs are advertised as 4 core ones, which means 2 modules in Bulldozer based Steamroller architecture. While each module has 2 separate cores, they share the floating point units. While AMD pushes the idea of iGPU handling the bulk of floating point tasks, it leaves the CPU at a disadvantage in many modern programs which do not take the advantage of GPU computing. Kaveri APUs are midrange CPUs in AMDs lineup and are similar in CPU performance to Intel’s dual core i3 CPUs.
The most interesting and attractive part of Kaveri are the improvements in the integrated GPU performance. While previous AMD APUs used the integrated graphics based on older GPU architectures, Kaveri has caught up to dedicated GPUs and uses the same GCN cores in its iGPU. This also brings the same level of driver support to the integrated graphics as enjoyed by the dedicated hardware. Finally, AMD’s TrueAudio and Mantle are much more important for its APUs to avoid CPU bottlenecks. iGPU in A10-7850K has 512 shader units at 720 MHz, while other two models only have 384 units. The difference in gaming performance between these iGPUs is in range of 10-20%. The performance of the less powerful version is slightly above the R7 240 graphics card which it can be paired with for multi-GPU rendering. It is not a lot of performance, but enough to play many modern games on medium settings at 1920x1080 with 30 FPS which is AMD’s target. It completely outperforms Intel’s HD 4600 iGPU, which is top model of socketed Intel CPUs. When put against the Intel’s most powerful, Iris Pro graphics, the results depend heavily on the resolution. Iris Pro can enjoy 30% advantage at 1280x720 in some games, but loses the lead at 1920x1080 in best cases and is 40% behind in the worst ones. Considering that Iris Pro is only available in BGA packaging and on the most expensive Intel CPUs, Kaveri can provide most powerful range of integrated graphics at a more affordable price.
Overall, AMD has provided an interesting offering for compact and mobile devices in Kaveri. The focus on the power of integrated GPU allows it to play most modern games decently. There is no similar offering from Intel, which would provide more iGPU performance without requiring you to pay for the most powerful CPU as well. It is no replacement for a powerful gaming system, but can be quite nice to have in light and cheap gaming capable laptops.
The Tech Report