… On the other hand, workloads that hit DRAM a lot suffer in NPS0 mode. 502.gcc, 505.mcf, and 520.omnetpp see the EPYC 9575F’s higher clock speed count for nothing, and the higher clocked chip underperforms compared to 4.4 GHz setups with lower DRAM latency. …
… DRAM requests are the most common type of off-CCD traffic. High LPDDR5X latency masks any latency advantage when looking at DRAM requests, as shown above. Cache coherency traffic is another form of off-CCD traffic, and doesn’t involve DRAM. …
… Single core DRAM bandwidth is also higher from a X925 core, at 38 GB/s compared to 26 GB/s from an A725 core. A single AMD Zen 5 or Zen 4 core can pull over 50 GB/s from DRAM, or well north of 100 GB/s from L3. …