AMD’s Ryzen 7 5800X3D does not support overclocking or PBO.Zilch | Computer Gamer

The Ryzen 7 5800X3D is AMD’s first consumer offering for its 3D V-cache technology, which adds another 64MB of L3 cache to its chips by physically mounting the cache on top of existing CPUs. The original CPU was slimmed down slightly to make room for this cache to ensure the overall package looks like any other Zen 3 CPU. This means it will work with existing coolers on existing motherboards. So far, so good.

The downside to adding this cache, though, is that AMD had to disable overclocking on the 5800X3D – in fact, this was confirmed by Robert Hallock a month ago. This is because frequency and voltage are inherently tied to how the cache works, so any tweaks to the CPU settings can disrupt timing and disrupt the entire process.