Intel Atom x5-Z8500 vs Intel Atom Z3775

Intel Atom x5-Z8500

The Intel Atom x5-Z8500 is a power efficient quad-core SoC for Windows and Android devices (tablets and convertibles), which has been presented in March 2015. It is clocked at 1.44 - 2.24 GHz and part of the Cherry Trail platform. Thanks to its new 14 nanometer low-power process (P1273) with tri-gate transistors, energy efficiency has been significantly improved over its predecessor Bay Trail-T (e.g. Atom Z3795). In addition to the CPU cores, the SoC offers a DirectX 11.2-capable GPU as well as a LPDDR3 Memory Controller (2x 64 bit, 25.6 GB/s).

Architecture

The processor cores are based on the Airmont architecture, which is basically a slightly modified shrink of the previous Silvermont core. While performance per clock has not been improved, the more efficient 14 nm process may lead to a better utilization of the CPU Burst (alias Turbo Boost) and therefore a somewhat higher performance in certain situations.

Performance

Compared to the Atom x7-Z8700, the Atom x5-Z8500 is clocked slightly lower and therefore 5 - 10 percent slower. However, the x5 still beats most ARM-based SoCs and offers a performance similar to a Qualcomm Snapdragon 810. 

Using Windows, the chip is adequate for everyday tasks such as Internet or Office, but not for very complex software or modern games.

Graphics

The HD Graphics (Cherry Trail) is based on the Intel Gen8 architecture, which supports DirectX 11.2 and is also found in the Broadwell series (e.g. HD Graphics 5300). With 12 EUs (Execution Units) and a clock speed of up to 600 MHz, the GPU is about twice as fast as the HD Graphics (Bay Trail) and will handle older and less demandig Windows games (e.g. Counter-Strike: GO) in very low settings at decent frame rates. The GPU also supports 4K/H.265 video acceleration.

Compared to ARM SoCs, the HD Graphics offers a performance similar to the Qualcomm Adreno 330 or PowerVR G6430.

Power Consumption

The entire SoC is rated at an SDP of 2 watts, which indicates a TDP of less than 4 watts. Thus, the chip can be used in passively cooled tablets.

Intel Atom Z3775

The Intel Atom Z3775 is a power efficient quad-core SoC for Windows and Android tablets. It is clocked at 1.46 - 2.39 GHz and part of the Bay Trail-T platform. Thanks to the specially optimized 22 nanometer low-power process (P1271) with tri-gate transistors, performance and energy efficiency have been significantly improved compared to its predecessor.

Compared to the Z3770, the Z3775 is based on the new C0 stepping and offers a slightly increased GPU clock rate.

Architecture

The processor cores are based on the new Silvermont architecture, which is an out-of-order design for the first time. The increased utilization of the pipeline and many other improvements (optimized branch prediction, increased buffers, enhanced decoders) have increased the performance per clock by about 50 percent. At the same time, however, the Hyper-Threading feature of the previous generation has been removed. Other major changes are the support for new instruction set extensions such as SSE 4.1 and 4.2 as well as AES-NI (depending on the model).

Performance

Thanks to 4 CPU cores and a clock speed of 1.46 - 2.39 GHz, the Z3775 is significantly faster than previous Intel Atoms, e.g. the Z2760. The Z3775 even beats some of the Kabini APUs like the AMD A4-5000, as well as ARM SoCs like Tegra 4 and the Snapdragon 800. For everyday tasks such as Internet or Office the performance is adequate, but not for very complex software or modern games.

Graphics

The HD Graphics (Bay Trail) is based on the Intel Gen7 architecture, which supports DirectX 11 and is also found in the Ivy Bridge series (e.g. HD Graphics 4000). With only 4 EUs (Execution Units) and a relatively low clock speed of up to 778 MHz, the GPU is even slower than the HD Graphics (Ivy Bridge) and comparable to the Qualcomm Adreno 320 (as found in the Snapdragon 600). Therefore, only older and less demanding Windows games will run fluently. However, video acceleration and display resolutions up to 2560 x 1600 pixels are no problem for the chip.

Power Consumption

The entire SoC is rated at an SDP of 2 watts, which indicates a TDP of less than 4 watts. Thus, the chip can be used in passively cooled tablets.