Re:Arm Unveils Next-Gen Flagship Core: Cortex-X3
by rbanffy on Wednesday June 29, 2022 @04:13PM
(#31925155)
> Imagine that power efficiency on servers. Saving so much energy.
There's no magic in those chips. Power efficiency is a design parameter you may optimize for or not, and ARM server chips dissipate more power because they have a lot more cores, more memory controllers, more cache, more IO, and, in general, a lot more stuff than a personal computer CPU would make sense to have. Computation per computation, they are not far from each other.
Intel's x86 ISA mandates a more computation to happen per amount of useful computation served - lots of memory write reordering, lots of instruction alignment (instructions can have from 1 to 15 bytes, IIRC) and other operations that do not translate into anything useful for the user beyond a higher IPC if your instruction stream is just right, but, also dissipate a lot of power for that.
There's no magic in those chips. Power efficiency is a design parameter you may optimize for or not, and ARM server chips dissipate more power because they have a lot more cores, more memory controllers, more cache, more IO, and, in general, a lot more stuff than a personal computer CPU would make sense to have. Computation per computation, they are not far from each other.
Intel's x86 ISA mandates a more computation to happen per amount of useful computation served - lots of memory write reordering, lots of instruction alignment (instructions can have from 1 to 15 bytes, IIRC) and other operations that do not translate into anything useful for the user beyond a higher IPC if your instruction stream is just right, but, also dissipate a lot of power for that.