Intel's New Chimera: Alder Lake

I feel that P and E split requires putting an asterisk next to the core count. it is dishonest to sell a CPU with N fully featured cores and M gimped cores as a CPU with N+M cores

Re: Intel's New Chimera: Alder Lake

#7

Post by quux » Sun, May 15, 2022, 6:57 AM UTC

mrath wrote: post #2

I don't have an idea on CPU design. Can this lead to M1 like performance?

The goal of this kind of design is M1 like energy efficiency, not performance (I don't know if the Alder Lake P cores can outperform an M1 P core.) M1 has a similar architecture with performance and efficiency cores, but so far I haven't heard of it causing problems for software developers. All versions of macOS that support M1 also have a scheduler that is able to move threads between E and P cores nicely.

Re: Intel's New Chimera: Alder Lake

#8

Post by iforgotpassword » Sun, May 15, 2022, 6:57 AM UTC

I wish there was at least a switch to allow the CPU to report the proper CPUID on each core and ideally, also keep AVX512 enabled. You could have a bios setting writing to an MSR. But I guess some idiot gamer somewhere might still enable this setting without understanding a word of the warning it's accompanied by and Intel wants to avoid that.

But I'm hopeful this is a stop-gap solution and we'll just make the p-cores more power efficient under medium load, and merely have the OS clock them lower when something is determined a background task. Then we "only" have to get that part to become smart enough.

Re: Intel's New Chimera: Alder Lake

#9

Post by esperent » Sun, May 15, 2022, 7:01 AM UTC

iforgotpassword wrote: post #8

I wish there was at least a switch to allow the CPU to report the proper CPUID on each core and ideally, also keep AVX512 enabled. You could have a bios setting writing to an MSR. But I guess some idiot gamer somewhere might still enable this setting without understanding a word of the warning it's accompanied by and Intel wants to avoid that. But I'm hopeful this is a stop-gap solution and we'll just make the p-core…

Such a condescending comment. Why should this "idiot gamer", who might be a child, be expected to know about this stuff?

Re: Intel's New Chimera: Alder Lake

#10

Post by kijiki » Sun, May 15, 2022, 7:02 AM UTC

I very much don't understand why Intel didn't disable AVX-512 on the P cores, unless and until the OS writes to a new MSR that means "I understand that the P cores can do AVX-512, while the E cores cannot", and then enable AVX-512 on the P cores.

Old OS versions continue to work fine, and newer OS versions can opt into the new world and benefit.