AMD EPYC 9755 DDR5-4800 vs. DDR5-6000 Memory Performance
With the newly-launched AMD EPYC 9005 series processors continuing to use Socket SP5, there is drop-in upgrade compatibility for existing EPYC 9004 series motherboards/servers. That's assuming, of course, the vendor provides a BIOS update for enabling the EPYC 9005 series "Turin" support and there may be limitations on the maximum CPU/TDP supported given power/thermal constraints. But in going from EPYC 9004 to EPYC 9005 is also upping the maximum memory speed from DDR5-4800 to DDR5-6000 (or DDR5-6400 in validated configurations). For those trying to weigh the benefits of also upgrading your memory if on an existing EPYC 9004 Genoa/Bergamo server to DDR5-6000, here are some memory performance comparison benchmarks for some reference points.
This article is quite simply looking at the performance of DDR5-4800 vs. DDR5-6000 on a single AMD EPYC 9755 128-core Turin (classic core) processor with twelve channel DDR5 memory. The AMD Volcano server was equipped with Samsung M321R8GA0PB1-CCPKC DIMMs running at DDR5-6000 speeds. While DDR5-6400 is advertised for Turin, it seems to be a rather late change and at least as of now appears that AMD will just be validating it for select configurations.
The point of this testing is to help those that may currently be using an EPYC 9004 server and considering an upgrade to the EPYC 9005 series but wondering about the "lost" performance if sticking to existing DDR4-4800 DIMMs as was standard for Genoa/Bergamo processors. Or similarly those that may be buying/assembling a new Turin server and trying to get an idea if the added expense for DDR5-6000 vs. DDR5-4800 is worthwhile depending upon your planned workloads. There are a lot more DDR5-4800 ECC RDIMMs available at major Internet retailers than DDR5-6000 if in a crunch or not running very memory bandwidth constrained workloads and trying to maximize your TCO savings. Hopefully the benchmarks in this article help quantify some scenarios with running more than 200+ benchmarks of various real-world minded workloads on the new AMD EPYC 9005 series processors.
From the AMD Volcano BIOS the DDR5 memory speed was manipulated for showing the same AMD EPYC 9755 1P server running at DDR5-6000 and then DDR5-4800. No other changes were made to this AMD EPYC 9755 server running Ubuntu 24.04 LTS besides comparing the memory speed in this article across dozens of workloads.