AMD released a Workload Tuning Guide: https://developer.amd.com/wp-content/resources/56745_0.80.pdf
AMD has advertised Epyc Rome to supporting 3200MHz DDR4. Why does it limit IFOP to 1467MHz instead of 1600MHz? Anyone knows the details of IFOP on Epyc Rome?
So, as the doc says, the Infinity Fabric will have a maximum speed of 1467 MHz (lower in some platforms).2.2.3 Memory Clock Speed
Benefit: By default, the BIOS for EPYC 7002 Series processors will run at the maximum allowable clock frequency by the platform. This configuration results in the maximum memory bandwidth for the processor, but in some cases, it may not be the lowest latency. The Infinity Fabric will have a maximum speed of 1467 MHz (lower in some platforms), resulting in a single clock penalty to transfer data from the memory channels onto the Infinity Fabric to progress through the SoC. To achieve the lowest latency, you can set the memory frequency to be equal to the Infinity Fabric speed. Lowering the memory clock speed also results in power savings in the memory controller, thus allowing the rest of the SoC to consume more power potentially resulting in a performance boost elsewhere, depending on the workload.
AMD has advertised Epyc Rome to supporting 3200MHz DDR4. Why does it limit IFOP to 1467MHz instead of 1600MHz? Anyone knows the details of IFOP on Epyc Rome?