Qualcomm Snapdragon 865 in detail

The Qualcomm Snapdragon 865 with Cortex-A77-CPU and Adreno-650-GPU is a logical development of the Snapdragon 855 and will drive high-end smartphones in the coming year. The division of the platform into two components is more surprising: AP and modem. In addition, the ISP has been significantly bored out.

Contrary to expectations during the year, Qualcomm did not present the Snapdragon 865 with an integrated 5G modem today. Instead, the Snapdragon 765 (G) is the first appropriately equipped chip for the upper middle class. Qualcomm says there is one reason why this is not the case with the Snapdragon 865: the performance of the modem. The Snapdragon X55 modem coupled to the Snapdragon 865 with multi-mode support for all standards from 5G to 2G could not have delivered the same performance when integrated into the SoC as if it were a separate chip. This is illustrated by the direct comparison to the integrated Snapdragon X52 modem of the Snapdragon 765 (G), which does not achieve the high data rates of the Snapdragon X55.

Snapdragon 865, 855, Exynos 990 and Kirin 990 5G compared

The fact that Qualcomm is again offering a pure AP (Application Processor) for the first time in six years can also be explained by other areas of the chip that are taking up more die space this year and thus taking up space on the Snapdragon X55. After yesterday’s rudimentary announcement, BitcoinMinersHashrate explains in detail what features the Snapdragon 865 offers. The following table describes the most important properties of the SoC compared to the predecessor Snapdragon 855 (+) as well as the Samsung Exynos 990 and HiSilicon Kirin 990 5G.

ARM Cortex-A77 arrives

In the CPU area, Qualcomm relies on the new Cortex-A77 from ARM, which is supposed to deliver 20 percent more power than its direct predecessor with a revised front end and new L0 cache. According to ARM, the Cortex-A77 takes up 17 percent more space on the die with the same manufacturing process. In the Snapdragon 865, the Cortex-A77 is called Kryo 585. Its own name is said to justify changes such as the Prime Core with 2.84 GHz and the doubled L2 cache. The 1 + 3 + 4-core design also consists of three other Kryo 585 Gold based on the Cortex-A77, which operate at the same clock rates and caches as last year, and four Kryo 585 Silver based on the Cortex-A55 together. The smaller cores work again at 1.80 GHz and offer 128 KB L2 cache.

Two memory interfaces for LPDDR5 and LPDDR4X

The double-designed memory interface, with which Qualcomm covers the new LPDDR5 standard and the LPDDR4X previously used, has also proven to be not exactly space-saving. JEDEC adopted the new standard, which delivers up to 50 percent more throughput, in February of this year, associated chips according to LPDDR5-5500 are available from Samsung, for example. Qualcomm supports this LPDDR5 with 2,750 MHz in the Snapdragon 865, while the older LPDDR4X remains at the well-known 2,133 MHz.

Adreno 650 goes wide

The graphics unit should also offer 20 percent more power than the Adreno 640 of the Snapdragon 855. As Qualcomm currently operates the GPU at practically unchanged clock rates to keep efficiency at a high level, the design has to be wider with more execution units in order to achieve more performance apart from architectural improvements. The GPU is therefore also a component that occupies more die area than before in the SoC.

The graphics unit can be used to control displays with up to 4K resolution at 60 Hz or with the more frequently used QHD + resolution at 144 Hz. Qualcomm has also integrated new gaming features that allow, for example, segmented optimization of SDR content towards HDR. The GPU carries out a pro-frame analysis in order to only adapt individual areas of the image for HDR, but not to falsify skin tones, among other things. Qualcomm worked with the creators of Unreal Engine 4 to be able to offer familiar features from the desktop, such as dynamic shadows, planar reflections, motion blur and the processing of more multiple light sources, on the Adreno 650 GPU.

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