Mediatek MT6582 vs Mediatek MT6589T vs Mediatek MT8125

The Mediatek MT6582 is a system-on-a-chip (SoC) for low-cost tablets and smartphones. It is manufactured in 28 nm and offers a quad-core Cortex-A7 processor as well as an ARM Mali-400 MP2 GPU clocked at 500 MHz (according to Wikipedia the main difference to the MT6582M that is clocked at 416 MHz). Furthermore, the chip supports dual SIM, UMTS and HSPA+, WiFi, FM, Bluetooth and GPS. 

The CPU performance of the MT6582 is similar to other Cortex-A7 SoCs clocked at the same frequency. Depending on the benchmark, the CPU power is roughly comparable with the Nvidia Tegra 3 and sufficient for everyday applications such as browsing. The GPU will handle only simple Android games in moderate resolutions.

The Mediatek MT6589T is a low-end system-on-a-chip (SoC) found in many inexpensive smartphones. It is manufactured in 28 nm and integrates a Cortex-A7-based quad-core CPU clocked at 1.5 GHz, a PowerVR SGX544 GPU clocked at 357 MHz, dual SIM and UMTS/HSPA+ support (up to 21 Mbps) and 1080p30 video decoding and encoding.

Both the CPU and GPU offer performances similar to an Nvidia Tegra 3 or the Samsung Exynos 4412 and Mali-400 GPU. Performance-per-clock of the Cortex-A7 is only slightly below that of a Cortex-A9, which can be found in the two aforementioned rivals. The graphics unit offers sufficient power for multimedia tasks and simple games, but not for extremely high resolution displays or complex 3D graphics.

Thanks to the modern 28 nm manufacturing and comparatively low performance, the power consumption of the entire chip is likely very low in order to be compatible with smaller smartphones and battery capacities.