AMD came in for some harsh criticism when it announced that its new Ryzen 5000 Mobile U-series processors would not all be using its …
AMD came in for some harsh criticism when it announced that its new Ryzen 5000 Mobile U-series processors would not all be using its latest core design. At the product announcement, we were told that some of the U-series processors would be based on the previous Zen 2 generation, and this was mainly for partners to take advantage of the new naming scheme but also reuse designs with the same ballpark performance. A number of tech enthusiasts (including myself, I have to say) scoffed at this as it made the whole system complex. It’s still complex, but we’ve come to understand that these latest Zen 2 based mobile processors also include a whole raft of updates that make them a better version of what they are. To simplify things I’m going to call these products by their AMD codenames. The older Zen 2 processors are called Renoir, and the newer Zen 2 processors are called Lucienne. Here is a list of the new Ryzen 5000 U-Series, with Lucienne listed in yellow. Renoir, for all intents and purposes, was a very successful product for AMD. Placed in the Ryzen 4000 Mobile series, it became the bedrock of AMD’s mobile portfolio and has been installed in around 100 design wins since it came to market. Lucienne on the other hand is a minor player in the latest Ryzen 5000 Mobile series. It doesn’t have the updates that the new Zen 3 cores have, but we have since learned that on the power side of things, rather than being a copy of Renoir, it is almost certainly Renoir Plus. What Lucienne brings to the table over Renoir comes in discrete categories. The memory controller in Lucienne is now able to decouple its voltage from the cores and enter a lower power state when not in use or for low bandwidth reasons. This ultimately saves power, and AMD has enabled it to bypass particular voltage indicators to help it stay in the low voltage state. Aside from the cores and the graphics, the other two consumers of power inside a mobile processor is the internal communications and the external communications, of which the memory controller falls under the latter. AMD has also put into place a system by which the memory controller can wake to a full bandwidth state faster than before, enabling better responsivity from those deep sleep states. On top of this, the memory controller can now support double the capacity of memory from Renoir: up to 64 GB of DDR4-3200, or up to 32 GB of LPDDR4X-4267.
