In short: Intel announced that its Alder Lake lineup will arrive in the coming months and seemingly confirmed the specs that have been leaked over the past few months. The company has also provided optimization guidance for game developers looking to get the most out of the new hybrid CPU architecture.
Intel Friday released his Alder Lake Developer Guide, a detailed look at how game developers can leverage the company’s new 12th generation architecture. Alder lake processors. That being said, he also confirmed some details about the upcoming processor line that have been leaked over the past few months.
It is no secret by now that some Alder Lake processors will ship with a hybrid architecture combining P-cores (performance), dubbed Golden Cove, and E-cores (efficiency), dubbed Gracemont. However, we also know that Intel will use this configuration on all Alder Lake laptops and desktops, with the exception of entry and mainstream desktop SKUs like the Core i5-12400, which could prove to be the next king of value.
Alder Lake-S processors are aimed at enthusiasts and will have up to 8 P cores and 8 E cores, while the main and low-end variants will only have P-cores. In any case, they will all come with an integrated Intel Xe graphics core with 32 execution units.
Meanwhile, Alder Lake-P parts will include all SKUs that used to belong to the U and H subfamilies. Higher-end mobile components will have 6 P-cores and 8 E-cores, while low-voltage parts will combine two P-cores. -core and 8 E-cores. All Alder Lake-P processors will be paired with Intel Xe graphics core with 96 execution units.
Only the L3 cache is shared between the P-cores and the E-cores, which allows them to work separately depending on the workload running on them. Intel chose to keep the same instruction sets for both core types, with the notable exception of E-cores, which do not support AVX512 workloads due to their current architecture. This also means that if a laptop or desktop manufacturer decides to enable E-cores, AVX512 will be disabled on P-cores.
Taking a page from Apple’s book, Intel’s Tread Director (ITD) and Microsoft Software Optimization in Windows 11, application and game developers will be able to tune target kernels based on the task they need to complete. Hybrid kernels will be functionally identical to the operating system, but the ITD and OS will manage the distribution of tasks between the appropriate kernels based on special classes that indicate the relative levels of performance and efficiency.
Game developers will also be able to use Intel’s manual interaction tools with the ITD if they find that the OS scheduler does a poor job of distinguishing between light and heavy tasks. In fact, they will be able to make a lot of optimizations, such as using E-cores for multithreaded workloads to prevent maximum P-core utilization, or parking E-cores to give more power to E-cores.
At the same time, setting thread priority and binding for things like game rendering and sound will be a little more difficult than in a non-hybrid architecture. This is because E-cores have two logical processors, while P-cores do not, and the OS may decide to assign a high-priority task to the E-core simply because it was immediately available. In other words, some applications and games may run slower on systems equipped with an Alder Lake processor if they do not have the necessary optimizations, even if the OS scheduler should do a decent job in most cases.
“Analysis of games on hybrid architectures showed that most games work well, with older or less demanding games preferring performance kernels,” the authors of the guide note. “Games that were already built for heavy multithreading and that can scale to double-digit cores have benefited from the hybrid architecture because of better throughput. However, there are unavoidable performance inversions due to either poor architecture of multi-threaded games, or poor OS scheduling or increased threading overhead. “
Intel also notes that Microsoft has added partial ITD support to Windows 10, but you’ll have to update to the latest version, 21H2. This means that if you are buying or building a new PC and you don’t like Windows 11, you will still be enjoying some of the benefits of Intel’s latest CPU architecture.