L-MOK7H Posted November 5, 2021 Posted November 5, 2021 https://www.pcgamer.com/intel-core-i9-12900k-review-benchmarks-performance/ What's different about the Intel Core i9 12900K? The Core i9 12900K represents the very best in Intel's desktop 12th Generation processors, and what that means is it houses the Alder Lake architecture in its most performant form. At its simplest, that equates to more cores, more speed, and more bandwidth than ever before, but if you dig beneath the surface you'll find a chip architecture that is wildly different to what came before. With that comes frame rates, OS requirements, and idiosyncrasies. All of which makes for fascinating analysis. The most notable change of the lot for Intel Alder Lake is the hybrid Core architecture. So let's dig into it, starting with the process that defines the entire chip: Intel 7. Alder Lake is Intel's first desktop processor to use the Intel 7 process node, which was previously referred to as Intel 10nm SuperFin, and also the first in a very long time to not use the 14nm process node. Oh, how times have changed. Intel has finally broken free the shackles of 14nm and managed to escape the node that was once so congested it caused a fairly embarrassing pile-up for the chipmaker. With Alder Lake, it's no longer tied to that node, so it's free to do more in the space it's got, and the company says it even expects to shift a lot of Alder Lake chips this side of New Year So perhaps this is some silicon you'll actually be able to buy at launch. Here's hoping, anyways. The most notable change of the lot for Intel Alder Lake, though, is the hybrid Core architecture. What this means is that Intel is stuffing all of the K-series 12th Gen chips, those which are arriving at launch, with two types of cores: Performance Cores (P-Cores) and Efficient Cores (E-Cores). Advertisement The P-Cores are based on the Golden Cove microarchitecture, which is one step beyond the Willow Lake microarchitecture found in Intel's 11th Gen mobile Tiger Lake processors. In desktop terms, that's roughly two steps on the architectural marathon from the backported Sunny Cove microarchitecture, renamed Cypress Cove, in Intel's 11th Gen Rocket Lake desktop processors, such as the Core i9 10900K. Intel Alder Lake chip render over gradient background (Image credit: Intel) And you're probably already thinking that's a lot of architectural codenames, and you'd be right. Alder Lake is like a Russian nesting doll of architectures. It doesn't get any easier, either, but it is quite a bit more exciting for it. Alder Lake's P-Cores are more closely related to the CPU cores of previous Intel desktop generations. Take the Core i9 10900K, for example, which has eight CPU cores in total. Consider the 12900K's eight P-Cores in much the same way, although considerably faster. For gaming these P-Cores are key. They offer the highest clock speeds of the two—on the Core i9 12900K these reach 5.2GHz at times—and nail down slick single-threaded speed for it. They're also built to minimise latency, and they're technically wider and smarter to catch up with the competition. That's AMD's savvy Zen 3 architecture, by the by. Advertisement Each P-Core has access to 1.25MB of L2 cache. From there, they're hooked up to 30MB of Intel Smart Cache, which is also shared between E-Cores and onboard integrated graphics (disabled in KF-series chips). For a marker of performance, the Core i9 12900K's P-Cores are able to surpass the Cypress Cove cores in the Core i9 11900K by a significant margin, and we're yet to touch on the eight Efficient Cores that Intel has stuffed into the 12900K's back pocket. The Efficient Cores are built on the Gracemont architecture, whose origins are in the Atom lineup. Traditionally built for lower-power, lower-performance processors, Intel has decided that its Atom architecture may find a use in more powerful processors after all, and the Core i9 12900K features eight Gracemont Efficient Cores in total. That's eight Efficient Cores clustered into two groups of four, each group with access to 2MB of L2 cache. These then share access to that same 30MB of Intel Smart Cache that the P-Cores are also privy to. I'll admit I wasn't always sure about Intel's Efficient Cores. Chip designer Arm has been rolling out big.LITTLE designs for a while, to great success, but primarily in the mobile market where power efficiency equates to longer battery life. Intel intends to bring Alder Lake to mobile, too, so I get that angle, but on the desktop side of things, it didn't first appear that these would be of tremendous value. What is a cluster of small cores, built out of Intel's next-gen Atom architecture, going to deliver a PC gamer like me? Well, I should've known it wasn't all about raw numbers, clock speeds, and single-threaded performance, because Intel's Efficient Cores are much more than you might first imagine. These Efficient Cores serve a couple of functions with Alder Lake. For starters, they help increase the multi-threaded performance, as you've simply got more cores to throw at a problem. Then, there's the ability to remove load from the P-Cores in a pinch, which is really where these low-power cores come in handy for gaming. Say you're a streamer and you're trying to play a competitive title on one screen and beam your capture off to the world on the other. An Alder Lake CPU, with a little help from Windows 11, should be able to divvy up this workload in order to keep your P-Cores focused on delivering gaming frame rates and your E-Cores on streaming that over the web. Intel Alder Lake's Thread Director diagram from an Intel event deck describing the goals and stages Intel's Thread Director works in tandem with Windows 11 (Image credit: Intel) Advertisement Therein lies some of Alder Lake's magic, but there's more to getting all of these architectures working together than simply placing them all on one chip. A large part of Intel's Alder Lake performance comes from utilising these two different cores in an effective manner, and to do that it uses something called the Thread Director. The Thread Director helps your OS decide which tasks should go to which cores, by handing your OS more information than it would otherwise have available to it. Through constantly monitoring and feeding thread information back to the OS, Thread Director works to make sure your game always gets priority over your RGB lighting controller doing an update. Thus keeping your frame rate steady. Ultimately, though, it's your OS that makes these decisions, and that's why Thread Director works best with Windows 11, which Intel worked with Microsoft on to get just right for Alder Lake. The use of a hardware embedded Thread Director has a couple of knock-on effects for us, then. Firstly, it means you'll really want to use Windows 11 if you have an Alder Lake processor for the best performance, which has its ups and downs and isn't entirely an OS we recommend today. Secondly, there are still some oddities in the Alder Lake architecture and optimisation that mean these two different cores either aren't utilise to their fullest, or don't function at all with a handful of games. Now, granted, a processor with a straight 16-cores is able to manage multiple workloads just fine, too, such as the Ryzen 9 5950X, but Alder Lake does have a few more performance boons up its sleeve.
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