Running The AMD EPYC 9754 CPUs With A 320W cTDP To Enhance Power Efficiency

The new AMD EPYC Bergamo and Genoa-X processors have been very fascinating in the lab from the performance angle and the many different features and knobs provided by these new high-end server processors focused on dense cloud and energy-efficient deployments and HPC/AI, respectively. With Bergamo the flagship AMD EPYC 9754 provides 128 cores with SMT and the Zen 4C cores still boast AVX-512. Another nifty aspect on this high core count CPU catering to cloud service providers is the adjustable TDP from 320 to 400 Watts. Prior Phoronix benchmarks have looked at the default 360 Watt performance and the 400W at the high-end with power determinism mode while today's article is looking at the efficiency gains made possible by pulling back to a 320W cTDP.

The AMD EPYC 9754 with its 128 cores / 256 threads features an all-core boost speed of 3.1GHz and base clock of 2.25GHz. The default TDP is 360 Watts but like most EPYC processors does have a configurable TDP from the BIOS for a range of 320 to 400 Watts. Setting 400W and switching over to the power determinism mode can help juice out a bit extra performance from the EPYC CPUs as shown in prior Phoronix articles. On the opposite side, the TDP can be lowered to deliver nearly the same level of performance in most workloads while conserving a bit of power in order to enhance the overall power efficiency of the server.

Today's article has the key CPU results from last week's reviews but now adding in the EPYC 9754 2P results when running with a 320W cTDP. These numbers are alongside the stock EPYC 9754 2P at 360 Watts, the EPYC 9754 2P at 400 Watts, and then the EPYC 9684X 2P stock and at 400 Watts and the same for the EPYC 9654. Plus the Intel Xeon Platinum 9480H 2P "Sapphire Rapids" results for reference.

The combined CPU power consumption was looked at via the RAPL/PowerCap interfaces and all this testing was done on Ubuntu 23.04 for having a modern Linux stack.