With the new AMD EPYC 9005 processors there are SKUs up to 500 Watt with the likes of the EPYC 9965 flagship at 192 cores for Turin Dense cores or 128 Turin classic cores with the EPYC 9755. But for those looking at upgrading from an existing EPYC 9004 series server and bound by the motherboard BIOS support and/or cooling/power capacity, 400 Watts is a sweet spot. Many of the existing platforms designed for EPYC 9004 Bergamo/Genoa(X) and now extended for EPYC 9005 Turin are limited to a 400 Watt TDP. With the prior AMD EPYC 9655 testing I have already shown off the great Zen 5 uplift when maintaining the same core counts as Zen 4, but even sticking to 400 Watts at the top-end is room for more. The EPYC 9845 is AMD's top-end SKU for 400 Watts or less that allows for 160 dense cores (320 threads) per socket compared to the 128 core EPYC 9754 Bergamo. Effectively the same power level and 25% more -- and better (Zen 5C) -- cores. Plus with EPYC Turin supporting the new AMD P-State CPU frequency scaling driver there is greater headroom in optimizing for power efficiency if so desired. Here is a look at how the AMD EPYC 9845 delivers a great leap to performance and power efficiency for those looking at a surprisingly robust upgrade from prior generation EPYC 9004.