How come a mobile CPU has more transistors than a desktop CPU?

[neeshantcharlie]

I was surprised to learn that the Snapdragon 855 mobile CPU has 1.5 times the transistor count than the Ryzen 5 3600. Both have the same fabrication size of 7nm. Then how come a big desktop CPU has lower number of transistors than a tiny mobile CPU. And how come the Ryzen performs many, many times faster than the Snapdragon?

[badreg]

The short answer is that the Snapdragon 855 is not a CPU; it's an SoC. It contains a CPU, GPU, I/O, radios and everything else needed for an entire system. The number of transistors in the actual CPU is a fraction of the total, and the number of transistors per core is far less than what a Ryzen core has.

 

Additionally, mobile SoCs are designed to work with fractions of a watt compared to the 100-200W budget that desktop processors have, so the transistor count alone is not an indication of processing power.

[The Sloth]

  

37 minutes ago, neeshantcharlie said:

big desktop CPU has lower number of transistors than a tiny mobile CPU.

becouse, they are a SOC that fits in GPU, CPU, modem, ram, DSP, ISP, security chips....ect. 

 

37 minutes ago, neeshantcharlie said:

. And how come the Ryzen performs many, many times faster than the Snapdragon?

ARM vs X86, the snapdragon is designed for low power usage. ARM is a RISC (Reduced Instruction Set Computing) architecture while x86 is a CISC (Complex Instruction Set Computing), so ARM uses less silicon area. 

 

 

 

[neeshantcharlie]

Great explanations! Thank you!