If AMD became the queen of desktop performance a few months ago with the Ryzen 5000, now with those just presented at its CES conference, the Ryzen 5000HX, AMD has taken the lead in laptops and for this they have made changes that go beyond the adoption of the Zen 3 kernel.
Four times the L3 cache of AMD Ryzen 9 5000HX
Last year when AMD launched its monolithic version both in the SoC and the processor of its cores Zen 2, these came with a big reduction and that is that the amount of L3 cache by CCX had been reduced from 16MB from the chip-based versions to just 4MB, which is what the new generation video game consoles have. also inherited from their SoCs to measure.
With Zen 3 there have been two important changes, the first of which is that now each CCX is 8-core and the second is the increase in the IPC in the processor, but if we talk about the AMD Ryzen 5000HX There has been a second change and that is the increase in the amount of L3 cache available to the processor.
Joining the two quad-core CCXs into an eight-core also adds caches, so each core has twice the L3 cache available as before, but the Ryzen 5000 Mobile doesn’t have 8MB of L3 cache but 16 MB, quadrupling the ratio compared to the previous generation.
What are the benefits of increasing L3 cache in the AMD Ryzen 5000HX?
To begin with, keep in mind that in all Zen architectures, from Zen to Zen 3, the L3 cache is a “victim cache”, which is responsible for collecting all the cache lines rejected by the L2 cache, it is not part of the process of capturing data and instructions as a conventional last level cache would, because although the data passes through the communication infrastructure between the L3 cache and the SDF / Northbridge in the direction of the first, they are not stored in said cache.
But increasing the capacity of the “victim cache” prevents a large number of rows from ending up in memory, which means that if a CPU core needs to access memory again, it does not need to. ‘go to RAM and can consult in this case the L3 cache. This is very important in power dependent systems such as laptops because the closer the data, the fewer parts of the processor are activated and therefore the power consumption is lower.
Is this going to be a trend in the rest of the Ryzen 5000 Mobile?
In principle there should be no change in the amount of cache for the AMD Ryzen 5000H and AMD Ryzen 5000U compared to the AMD Ryzen 5000HX, remember in passing that some models of the Ryzen 5000U are based on Zen 2 and not Zen 3, so they wouldn’t benefit from this increase in third-level cache.