Qualcomm Snapdragon 821 MSM8996 Pro vs Qualcomm Snapdragon 800 MSM8974

Qualcomm Snapdragon 821 MSM8996 Pro

The Qualcomm Snapdragon 821 MSM8996 is a high-end ARM-based SoC largely found on Android tablets and smartphones. Announced in mid 2016, the S820 is the successor to the Snapdragon 820 and from a technical perspective a higher clocked version of the SoC. In addition to 4 CPU cores (two slower clocked and two faster clocked Kryo cores), the SoC integrates an Adreno 530 GPU with a LPDDR4 memory controller  and supports Wi-Fi (802.11ad + MIMO), Bluetooth 4.1, and LTE.

CPU

The Snapdragon 821 is based on a similar concept as ARM's big.LITTLE, which combines a low power CPU cluster (2x Kyro clocked at up to 1.6 GHz?) and a performance CPU cluster (2x Kyro clocked at up to 2.4 GHz). The clock speed of each cluster can be individually adjusted (but not per core) and the lowest clock speed is 310 MHz. The performance cluster features 1 MB L2 cache and the power saving one 512 KB. Both should be using the same architecture and fully support the ARMv8-ISA instruction set.

Although only four cores are used, the performance of the 821 is located in the high end of mobile CPUs for smartphones and tablets. The performance advantage of the 821 compared to the 820 depends on the used clock speed. E.g. in the Google Pixel, the SoC is only clocked at 2.15 GHz and therefore identical to many 820 SoCs.

GPU

The Adreno 530 outperforms the previous Adreno 430 especially in high demanding benchmarks. Therefore it is well suited of modern 3D games on Android devices and should rank slightly below the Tegra X1 GPU. Compared to the 530 in the 820, the 821 version should be up to 5 % faster, which speaks for a slightly higher clock speed.

Features

The Snapdragon 821 offers numerous wireless technologies such as Bluetooth 4.1, WLAN 802.11a/b/g/n/ac/ad (60 GHz) + MIMO as well as a dual-SIM cellular modem supporting LTE cat. 12/13 .

The SoC can encode and decode 4K videos using dedicated hardware (H.264 and H.265).

Power Consumption

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

Qualcomm Snapdragon 800 MSM8974

The Qualcomm Snapdragon 800 MSM8974 is an ARM-based SoC for tablets and smartphones. It is built at TSMC in a 28nm HPM (High Performance Mobile) HKMG process, whereas the Snapdragon 600 was manufactured in 28nm LP. In addition to 4 CPU cores with a clock speed of up to 2.3 GHz, the chip also integrates an Adreno 330 GPU up to 450 MHz, an LPDDR3-1600 memory controller and various radio modules (UMTS/LTE, WiFi, Bluetooth, GPS).

Processor 

The CPU portion is based on Qualcomm's Krait architecture, which is compatible with ARMv7 ISA. Compared to the Snapdragon 600 (Krait 300), the new Krait 400 cores of the Snapdragon 800 have been tweaked just slightly with faster L2 cache. Thanks to a clock rate of up to 2.3 GHz and a high performance per MHz somewhere between an ARM Cortex-A9 and a Cortex-A15, the Snapdragon 800 offers very strong CPU performance. The S800 competes with the Nvidia Tegra 4, Samsung Exynos 5420 and Apple A7 and is therefore one of the fastest ARM SoCs on the market as of 2013.

Graphics

Another difference between the Snapdragon 600 and 800 is the graphics unit. While the S600 implements an Adreno 320 (400 to 450 MHz), the S800 features the faster Adreno 330 (450 MHz). Both GPUs offer the same amount of texture units (8 TMUs), but the Adreno 330 has 50 percent more shaders (probably 6x SIMD16 vs. 4x SIMD16 of the previous generation). In conjunction with the higher memory bandwidth, the performance is significantly better. As a result, the Adreno 330 is slightly faster than the Mali-T628 (Exynos 5420) and the PowerVR G6430 (Apple A7). Depending on the device and cooling, however, the performance may vary. The GPU supports OpenGL ES 3.0 as well as OpenCL 1.2.

Features 

Furthermore, the MSM8974 supports many wireless technologies: Bluetooth 4.0, WLAN, IEEE 802.11a/b/g/n/ac (2.4/5 GHz), GSM (GPRS, EDGE), W-CDMA/UMTS (HSDPA, HSUPA, HSPA+, cat.29 DC-HSPA+), MBMS, cat.4 LTE, CDMA2000 (1X RTT, 1 × EV-DO Rel.0/Rev.A/Rev.B, 1× EV-DO Rev.A MC, 1× Adv Rev.A/Rev.B) and TD-SCDMA. 

The MSM8974 can encode and play UHD 4K videos in 3840x2160 at 30 FPS (120 Mbps H.264 High Profile) sumiltaneously via dedicated hardware. Moreover, it supports both USB 2.0 and 3.0 and cameras up to 55 megapixels and stereoscopic 3D.

Power Consumption

Thanks to the new 28nm HPM HKMG process, the energy efficiency has been improved significantly compared to its LP 28nm S600 predecessor. Depending on the field of application, the maximum power consumption should be about 3 W for smartphones or 4 W or greater for tablets. This should be similar to comparable ARM SoCs currently in the market.