Intel's 15th Gen Arrow Lake CPUs Could Get A Huge P-Core Cache Boost
Intel's 12th-generation Alder Lake CPUs aren't that far from its 13th-gen Raptor Lake chips. There are lots of changes, of course, but from an end-user perspective, the biggest difference is the upgrade in L2 cache. Raptor Cove P-cores sport 2MB, and the E-core clusters have 4MB. That's up from 1.25MB and 2MB on Alder Lake, and this change is responsible for most of the improvements in single-threaded speed between the two generations.
Next up on Intel's docket will be the first "Core Ultra" family, codenamed Meteor Lake and probably coming primarily or exclusively to laptops. On the desktop, we'll have 14th-generation Core processors, known as Raptor Lake Refresh, but those will likely be the last processors of their line. After Meteor Lake will come Arrow Lake, which should find its way to both laptops and desktops.
Raptor Lake smokes Alder Lake, but 3D V-Cache is impressive, too.
The bigger caches give Raptor Lake a considerable performance advantage over Alder Lake. While it's not as big of an improvement as AMD's CPUs get from their 3D V-cache, it's still a significant step up. It looks like Intel is well aware of this, as the latest rumor from frequent Chinese source Golden Pig Upgrade Pack says simply that Arrow Lake will see another L2 cache increase, this time to 3MB for its Lion Cove P-cores.
That's a 50% bump in L2 cache compared to Raptor Cove. Even if Arrow Lake's Lion Cove core architecture had no other changes from Raptor Cove, that would probably still offer significant single-threaded performance improvements. Intel hasn't said a word about Lion Cove yet, and we only really know it exists or is being used in Arrow Lake thanks to it appearing in a perfmon update, but we expect it will probably have more significant architectural changes than just the cache upgrade.
Assuming that the L3 cache configuration hasn't also changed, this will give Arrow Lake's P-cores 3MB of L2 cache as well as 3MB of L3 cache per P-core. In Alder and Raptor Lake, each P-core and each E-core cluster gets 3MB of L3 cache, totaling 36MB of L3 cache for a fully-enabled Core i9-13900K. That's quite a bit less than one of AMD's 3D V-Cache CPUs, which sport a 64MB L3 cache upgrade giving a single-CCD chip 96MB of L3 cache. However, AMD's Zen 4 cores only have 1MB of L2 cache, so the larger last-level cache is critical.