Linux 6.5 now defaults to the AMD P-State EPP driver for Zen 2 and newer Ryzen systems, as long as the system supports ACPI CPPC. However, the AMD EPYC server processors still continue to use ACPI CPUFreq by default. Given the increasing interest in the AMD Ryzen 7000 series for budget and small-to-medium-sized business (SMB) servers, the performance impact of Linux 6.5 with more server workloads was analyzed.

Phoronix has tested the changes, and testing was conducted comparing the performance of Linux 6.4 against Linux 6.5, both out-of-the-box and using the Ubuntu Mainline Kernel PPA for easy reproducibility. The default change involves going from ACPI CPUFreq Schedutil to AMD P-State EPP with the powersave governor. Additional tests were done with the performance governor for maximum performance. AMD P-State is available on earlier Linux kernel versions but is not set to be used out-of-the-box until Linux 6.5 and later. The testing was done using the ASRock Rack 1U4LW-B650/2L2T, a 1U Ryzen AM5 server platform that supports Ryzen 7000 series processors and ECC memory. No other changes were made to the server during testing, except for swapping out the Linux kernel and running secondary tests with the performance governor. The CPU clock frequency differences in the automated system table were minimal and did not affect the testing results.

The article provides valuable insights for those interested in using Ryzen processors for server applications.

Source: Phoronix.

The Linux 6.6 kernel version seems to be delivering significant performance improvements for AMD EPYC server CPUs according to Phoronix. Tests conducted on Genoa and Genoa-X processors as well as Intel Xeon Scalable “Sapphire Rapids” processors showed that the performance of AMD EPYC servers was greatly enhanced with Linux 6.6 compared to Linux 6.5 stable. The improvements were especially notable for certain workloads.

The Linux 6.6 kernel introduces the EEVDF scheduler and workqueue enhancements that benefit chiplet-based CPUs with multiple L3 caches, such as those used by AMD. Overall, the new features in Linux 6.6 seem to be positively impacting AMD server CPU performance.

Source: Phoronix.

AMD has launched the AMD EPYC 8004 “Siena” processors for “intelligent edge” servers, according to Phoronix. These processors offer a lower price point while maximizing power efficiency and expanding EPYC’s deployment outside of data centers. The Siena processors have up to 64 cores / 128 threads per socket, support up to six channels of DDR5 memory, and are designed for edge computing and telco markets. They use the new “SP6” socket and have a range of TDPs from 70 Watts to 225 Watts. The EPYC 8004 series consists of P and PN parts, with PN parts being NEBS friendly. The pricing ranges from $409 to $5450 USD. The performance and power efficiency of the EPYC 8004 series are competitive against Xeon Scalable “Sapphire Rapids” processors. The processors offer the same ISA features as Genoa (-X) and Bergamo, including AVX-512, and support SMT. Overall, the EPYC 8004 series processors are complementary to Genoa (-X) and Bergamo, filling the gap between them and Ryzen for budget-minded and SOHO/SMB server deployments.

Source: Phoronix.