AMD Preps for Zen 4: Different Types of Cores Now Supported in Linux

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Genoa and Bergamo support is coming.

Tech sleuths are following AMD as it prepares its new Zen 4-based architecture. As the prepares its next-gen CPU, some eagle-eyed individuals have found details about the next-gen parts on Linux and other platforms.

AMD has quietly uploaded temperature sensor driver support for Zen 4 and Zen 4C cores, reports Phoronix. While these two cores share the same microarchitecture, they are different and will power AMD's 96-core Genoa and 128-core Bergamo processors, respectively, so it is not surprising to see separate drivers. The CPUs are marked as AMD Family 19h Models 10h-1Fh and A0h-AFh. 

Perhaps, a more intriguing innovation is a new Scalable Machine Check Architecture (SMCA) of some future AMD platforms that could use different types of SMCA and therefore cores. 

"Future AMD systems will have different bank type layouts between logical CPUs," wrote Yazen Ghannam, an AMD engineer. "So having a single system-wide cache of the layout won't be correct. […] Patch 1 adds new bank types and error descriptions used in future AMD systems. Patch 2 adjusts how SMCA bank information is cached." 

So far, AMD has not announced a single hybrid processor that integrates different types of cores, though the company has never completely excluded such a possibility. Since AMD will have Zen 4 and Zen 4C cores next year, perhaps this is the time when the company might consider a CPU with both big and smaller cores. Alternatively, a new SMCA may indicate that Zen 4C will have a different machine check architecture than other Zen cores, which is why AMD needs to implement its support into Linux. 

In any case, both the new temperature sensor drivers and SMCA implementation indicate that preparations for AMD's Zen 4-series cores are in full swing. 
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