After reviewing the AMD Ryzen 9 9900X and Ryzen 9 9950X Linux yesterday, today’s Ryzen 9000 series test takes a closer look at the performance impact of AVX-512. With the Ryzen 9000 series, the Zen 5 cores have a full 512-bit data path compared to the “double-pumped” 256-bit data path found in Zen 4 processors as well as Strix Point SKUs. In this article, we compare enabling and disabling AVX-512 not only for the Ryzen 9 9950X but also the previous generation Ryzen 9 7950X and look at CPU power usage, thermals, and peak clocks when dealing with a variety of AVX-512 workloads.
As shown in our Ryzen 9 9900X/9950X and Ryzen 5 9600X / Ryzen 7 9700X benchmarks/reviews, AVX-512 performance with Zen 5 is quite impressive. AVX-512 workloads benefit greatly from the Ryzen 9000 series’ 512-bit datapath and I wanted to take a closer look at the difference with today’s article by running benchmarks with AVX-512 enabled and then disabled – which can be done via BIOS or by booting the Linux kernel with “clearcpuid=304” to prevent AVX-512 extensions from being advertised in user space.
On both the AMD Ryzen 9 7950X and Ryzen 9 9950X, I ran the benchmarks with AVX-512 enabled and then disabled. I also monitored CPU power consumption, peak frequency, and CPU core temperature to see the overall efficiency of the Zen 5 AVX-512 implementation and how it compared to Zen 4 where AVX-512 was originally introduced on the AMD side.
This is a very direct comparison and does not involve any other changes to the system hardware or software except swapping processors and then running a secondary performance test with AVX-512 disabled.
