> The Power10 processor technology introduces the new OMI DIMMs to access main memory. This allows for increased memory bandwidth of 409 GB/s per socket. The 16 available high-speed OMI links are driven by 8 on-chip memory controller units (MCUs), providing a total aggregated bandwidth of up to 409 GBps per SCM. Compared to the Power9 processor-based technology capability, this represents a 78% increase in memory bandwidth.
And that is again a theoretical limit which usually isn't that interesting but rather it's the practical limit the CPU is able to hit.
For one, OMI is just like PCIe full-duplex; second, OMI-with-DDR4-3200 is substantially lacking in throughput vs. e.g. GDDR6 that was shown in the early Power10/OMI slides.
Also there's to note the substantial overprovisioning of the lanes to handle lane-localized transmission issues without degrading observed performance.
