Qualcomm Snapdragon 660 vs Qualcomm Snapdragon 808 MSM8992

Qualcomm Snapdragon 660

The Qualcomm Snapdragon 660 (SD660) is a fast mid-range ARM-based SoC largely found on Android tablets and smartphones. Announced in mid 2017, the SD660 is the successor to the Snapdragon 625. It features 8 Kryo 260 cores (custom design, 64-Bit capable) that are divided in two clusters. A fast cluster of four cores with up to 2.2 GHz and a power saving efficiency cluster with up to 1.8 GHz. Both clusters can also used together.

In addition to the 8 CPU cores, the SoC integrates a mid range Adreno 512 GPU with a LPDDR4 memory controller (dual-channel 1866 MHz)  and supports Wi-Fi (802.11ac + MIMO, max. 867 Mbps), Bluetooth 5, and LTE (X12 LTE modem with up to 600 Mbps download and 150 Mbps upload).

Performance

In Benchmarks of the Oppo R11, the CPU part of the Snapdragon SD660 performs between former high end Socs like the Snapdragon 821 in the Pixel XL and the Snapdragon 835. The graphics performance is however much lower, as the Adreno 512 is only a slight upgrade of the older Adreno 510 (due to the higher clock speed).

CPU

The Snapdragon 660 is based on a similar concept as ARM's big.LITTLE, which combines a low power CPU cluster (2x Kyro clocked at up to 1.8 GHz) and a performance CPU cluster (2x Kyro clocked at up to 2.2 GHz). The clock speed of each cluster can be individually adjusted (but not per core) and the lowest clock speed is 310 MHz (unverified).

Power Consumption

Thanks to the new 14 nm process, the energy efficiency has been improved noticeably compared to its 20 nm predecessors.

Qualcomm Snapdragon 808 MSM8992

The Qualcomm Snapdragon 808 MSM8992 is an ARMv8-based high-end SoC mainly for Android tablets and smartphones. Announced in April 2014, the S808 is positioned somewhat below the faster Snapdragon 810 and startet shipping in the first half of 2015 in the LG G4 smartphone. In addition to 6 CPU cores (2x Cortex-A57 and 4x Cortex-A53), the SoC integrates an Adreno 418 GPU, a 2x 32-bit memory controller (LPDDR3-1866, 14.9 GB/s) and supports Wi-Fi (802.11ac + MIMO), Bluetooth 4.1, UMTS and LTE.

CPU

The Snapdragon 808 is based on ARM's big.LITTLE concept, which combines different CPU cores for an optimal combination of performance and power consumption. In this case, there are two fast Cortex-A57 cores clocked at up to 2.0 GHz, which offer an about 30 percent higher performance per clock compared to the previous Cortex-A15 (e.g. Tegra K1) design. Furthermore, the SoC integrates four slower, but much more efficient Cortex-A53 cores (max. 1.5 GHz), which will handle background tasks and simple applications.

All six cores can be active at the same time, although most applications aren't parallelized to support 6 cores efficiently. In many cases, the S808 will be only slightly slower than the S810 (4x Cortex-A57 and 4x Cortex-A53). Both Cortex-A53 and -A57 are based on the ARMv8 ISA and therefore 64-bit capable.

GPU

The Adreno 418 is clocked at up to 600 MHz and based on the same unified shader architecture as the Adreno 430 (Snapdragon 810). However, the Adreno 418 offers just 128 ALUs, while the Adreno 430 integrates 192 shaders. Accordingly, the Adreno 418 is about 30 percent slower and also somewhat behind the Adreno 420 (Snapdragon 805).

Nevertheless, the GPU easily handles demanding Android games and high-res displays with resolutions exceeding FullHD.

Features

The Snapdragon 808 offers numerous wireless technologies such as Bluetooth 4.1, WLAN 802.11a/b/g/n/ac + MIMO as well as a dual-SIM cellular modem supporting LTE cat. 6 (up to 300 Mbps), WCDMA, CDMA, EV-DO, TD-SCDMA and GSM/EDGE.

The SoC can encode and decode 4K videos using dedicated hardware. A large number of video codecs including H.265 (for decoding) will be supported. The dual ISP can handle cameras with up to 55 MP.

Power Consumption

Thanks to a new 20 nm process (TSMC), the energy efficiency has been improved noticeably compared to its 28 nm predecessors. This allows higher performance while keeping power consumption on roughly the same level. Depending on the field of application, the maximum power consumption should be about 3 W for smartphones and 4 W or greater for tablets. However, 14 nm SoCs as the Samsung Exynos 7420 offer even better energy efficiency.