Following the Qualcomm Snapdragon 845’s official announcement, specs of three new Snapdragon SoCs including the Snapdragon 670 were leaked, and just a week later, benchmark results of the unannounced processor made their way online. New details about the Snapdragon 670 mobile processor have now been revealed by WinFuture, which has published kernel source code of the SoC, revealing nearly all the key details about its specs like cluster architecture, raw clock speeds, etc.
As per the information divulged by the kernel source, the Snapdragon 670 (SDM670) will be an octa-core processor, but it will ditch the conventional 4 x high powered cores + 4 x low-powered core configuration based on ARM’s big.LITTLE architecture. Instead, it will feature a 6+2 design consisting of a hexa-core low-end CPU cluster and a dual-core high-end CPU cluster. 
The six low-powered cores are a tweaked version of the ARM Cortex-A55 called ‘Kryo 300 Silver’ clocked at a maximum of 1.7GHz, while the two performance-oriented cores are a customized variant of the ARM Cortex-A75 known as ‘Kryo 300 Gold’ which have a peak clock speed of 2.6GHz. The numbers are quite impressive for a Snapdragon 600-series SoC, as the flagship Snapdragon 845’s performance cores have a slightly higher peak clock speed of 2.8GHz, suggesting that the Snapdragon 670 will be listed in Qualcomm’s line-up as a watered down version of the flagship CPU.
The CPU cores will come with 32KB L1 cache, the clusters will feature 128KB L2 cache and the complete SoC will have a 1024KB of L3 cache memory. As for the GPU paired with the upcoming SoC, the Adreno 615 (normal clock speed: 430MHz – 650MHz; max. clock speed: 700MHz) will handle the graphics department.
The Snapdragon 670 will feature support for screens with up to WQHD resolution as well as UFS 2.1 and eMMC 5.1 flash memory standards, and is also equipped with Qualcomm’s Snapdragon X2x modem which claimed to provide a maximum download speed of 1GBPS.
Xiaomi has (at least) 2 devices with the unannounced Qualcomm Snapdragon 670 (sdm670) in the works: "comet" and "sirius".
Also confirms @rquandt's report which showed sdm670's little cluster has 6 cores and the big cluster has 2 cores. (targetconfig.xml in /vendor/etc/perf).
— Mishaal Rahman (@MishaalRahman) April 7, 2018
XDA-Developers’ Editor-in-chief Mishaal Rahman has revealed that the Snapdragon 670 will power two upcoming Xiaomi smartphones code-named ‘Comet’ and ‘Sirius’, both of which are currently under development.
