Intel Arrow Lake processors will likely have different instruction sets for desktop and laptop computers
November 1, 2023

Intel Arrow Lake processors will likely have different instruction sets for desktop and laptop computers

While it’s not uncommon for desktop and laptop processors to differ somewhat, we don’t typically expect the mobile version of a chip to support fewer instruction sets (ISAs) than its desktop counterparts. However, it looks like this will be the case with the next generation of Intel Arrow Lake processors marked S (for desktop) and those marked H (for mobile devices).

This information is revealed in an unofficially published document by a Linux enthusiast from the social network Twitter (X) under the name @InstLatX64.

Thus, the Intel Arrow Lake-H processor will reportedly lack AVX-VNNI-INT16 (AVX made for neural networks) as well as three encryption and decryption instructions. While this may not matter to most users, it is definitely an interesting potential development in the processor market.

On the other hand, Intel Arrow Lake-S processors in LGA1851 will have, among other things, ISA support for the following: AVX-VNNI-INT16, SHA512, SM3, and SM4. In addition, the CPU will support the LBR Event Logging function. The exact reasons why Intel decided not to implement these features in mobile processors according to this document is unclear, but it is possible that the company could not add support for them because the very low-power x86 cores on the SoC matrix simply cannot support them.

In short, instruction sets (Instruction set architecture – ISA) are essentially a way for the processor to perform a specific operation, that is, a set of operations very quickly. They depend on the CPU cores and it is likely that at least one part of the SoC Arrow Lake version will be for both desktop and laptop devices. However, the mentioned low-power cores, specifically the two small power-efficient cores on the SoC will probably turn out to be the cause of these differences.

Although such cores in the processor are mainly intended to handle light background tasks and improve energy efficiency, they are still somewhat equal to more powerful cores when it comes to the operating system. If two E-cores do not support certain instructions, then the entire CPU cannot use them. Arrow Lake-H will likely use the same SoC as Meteor Lake, meaning there is no room for new ISAs, despite there being a new layout with updated cores that can support some new instructions.

On the other hand, there is the Arrow Lake-S designed for the desktop, for which battery life is not a problem. In addition, it will probably use more E-cores that are used for a wider range of tasks. In that case, disabling E-cores on the SoC will enable the instructions without much impact on performance, HotHardware concludes.