How to understand Kryo CPU numbering in Qualcomm Snapdragon processors

Qualcomm has a wide range of Snapdragon processors, divided into a set of series. The 800 series, for flagship processors; the 700 series, for premium mainstream; the 600 series for the mid-range; and so on. Each Snapdragon processor uses a different CPU and GPU combination. The CPUs use the Kryo branding and they have their own numbering scheme. Like many numbering schemes, it can be a bit confusing.

What is the difference between the Kryo 475 in the Snapdragon 765 and the Kryo 385 in the Snapdragon 845? Here is a quick explainer that should help you navigate the turbulent waters of Qualcomm’s CPU naming scheme.

Qualcomm Snapdragon Kryo CPU numbering explained

Kryo

The “original” Kryo CPU debuted in the Snapdragon 820/821 in 2015. It was a complete custom CPU design from Qualcomm. It was a 64-bit quad-core CPU, compatible with the ARMv8 architecture. It maxed out at 2.2 GHz and was made using a 14nm FinFET LPP process.

Kryo 2xx

By 2016, Qualcomm had signed a new deal with Arm which allowed it to use Arm designed CPUs however with two important benefits over other licensees of Arm cores. First, it could market the CPU cores under its own branding, Kryo. Second, it would have a say about the design of future CPU cores and could requests “tweaks” for its own semi-custom Kryo cores. Its first true semi-custom CPU design was the Kryo 485, found in the Snapdragon 855, but more about that in a moment. This new license agreement was branded as Built-on Cortex.

The Kryo 2xx CPUs use vanilla Arm Cortex-A73 and Arm Cortex-A53 CPU cores. They are found in the Snapdragon 835, 632, 636, 660, and 665. These are all octa-core CPUs with four Cortex-A73 cores and four Cortex-A53 cores. Depending on the exact model of processor, these CPUs are built using 10, 11 or 14nm FinFET LPP. Each of the Snapdragon processors that include the Kryo 2xx CPU, use it in slightly different configurations. For example, the Snapdragon 665 uses the Kryo 260, which has a max clocked speed of 2GHz and is built on 11nm. This is compared to the Kryo 280, in the Snapdragon 835, which maxes out at 2.45GHz and is built on 10nm.

Kryo 3xx

The Kryo 3xx series moves from the Cortex-A73/A53 to the newer Cortex-A75 and Cortex-A55. The Kryo 360 is found in the Snapdragon 670, 710, and 712. It uses a 2+6 setup, with two Cortex-A75 cores and then six Cortex-A55 cores. The Kryo 385 is used in the flagship Snapdragon 845 and the Snapdragon 850, a Windows on Arm laptop processor. Both use four Cortex-A75 cores and four Cortex-A55 cores. The Snapdragon 845 has a max clock speed of 2.8 GHz, up from the 2.45 GHz of the Snapdragon 835.

Kryo 4xx

The Kryo 4xx series was the first to truly benefit from the Built-on-Cortex partnership with Arm. While it is based on the Cortex-A76 and Cortex-A55, the A76 is a special semi-custom version supplied only to Qualcomm. The Kryo 4xx is also the most used CPU and is featured in 10 different Snapdragon processors, including the Snapdragon 855/855 Plus, the 765/765G and three laptop processors (the 8cx, the 8c, and the 7c).

The Kryo 460, Kryo 468, and Kryo 470, use the 2+6 setup (two A76 + six A55), whereas the rest all use the 4+4 setup. There is also a tweak to this variation with the Kry0 485 in the Snapdragon 855/855+, and the Kryo 475 in the Snapdragon 765/765G. The latter uses a 1+1+6 setup where one of the Cortex-A76 cores is clocked at a slightly higher frequency. It is known as the prime core. Likewise, the Kry0 485 also has a prime core with a high clock frequency and extra cache.

Kryo 5xx

The only CPU in the 5xx series at the time of writing is the Kryo 585 from the Snapdragon 865. Like the Snapdragon 855, it uses a prime core alongside three other high-performance cores, however this time they are based on the Cortex-A77. The Kryo 585 has a max clock speed of 2.84 GHz.

Kryo CPU numbering cheat sheet

Qualcomm Snapdragon 865 in hand back

A birds-eye view of the Kryo range looks like this:

Kryo = Qualcomm custom
Kryo 2 = Cortex-A73
Kryo 3 = Cortex-A75
Kryo 4 = Cortex-A76
Kryo 5 = Cortex-A77

From the Kryo 3xx series onwards there is a little cheat to help remember which Cortex CPU core is used. The last digit of the Cortex core is always two more than Kryo series number. So the last digit of the Cortex CPU in the Kryo 3 series is 5 (3 + 2) and so it is the Cortex-A75. For the Kryo 5, it is 5 + 2, which means the Cortex-A77.

If this shortcut will work for the Kryo 6xx series and the next Cortex CPU core, only time will tell! For more on the subject of Kryo CPU numbering, be sure to check out the video at the top of this article.