Intel has shed additional light on the performance of its P-Core & E-Core hybrid design architecture featured on Alder Lake CPUs. The company initially compared the performance increase versus the Skylake architecture but now, Intel has provided us the performance per power charts pitting its P-core and E-core next to each other.
Intel's P-Core & E-Core Hybrid Architecture For Alder Lake CPUs Detailed - 50% Higher Single-Core Performance For Golden Cove, 50% Higher Multi-Threaded Perf For Hybrid Cores
In the latest slides presented at HotChips 33, Intel shows the relative single-threaded & multi-threaded performance comparison between its P-Core (Golden Cove) and E-Core (Gracemont).
In single-threaded applications, a single P-Core (Golden Cove) delivers a 50% single-threaded performance increase over E-Core (Gracemont) within the same die area and power package. Intel's hybrid design, on the other hand, shows its prowess in multi-threaded performance, & delivers a 50% increase compared to a 4 P-Core solution.
The hybrid design featured 2 P-Cores (Golden Cove) and 8 E-Cores (Gracemont). The Hybrid design does offer 50% more threads to obtain its 50% lead over the standard 4 P-Core design (12 threads vs 8 threads) but it does so within the same package and power constraints.
Intel also talks a little bit more in-depth regarding its Thread Director technology and based on the new slides, Alder Lake cores will be segmented into specific IPC groups. This is a nice approach as IPC doesn't necessarily remain the same across all workloads or cores. What we usually see is an average IPC or baseline numbers based upon multiple workloads but in real-time, the OS scheduler needs to adapt to performance and efficiency bits of the architecture and this is where the Thread Director plays a crucial role.
For instance, in some scenarios, scheduling a thread for a small workload can bring overall better performance than scheduling for a large core and the same is true in regards to efficiency. Intel's Alder Lake CPU will be the first hybrid x86 outing on mainstream consumer platforms & requires a lot of work on the scheduling end to make the architecture work as intended. Both Microsoft and Intel are working to deliver stable performance at launch with Alder Lake and the Windows 11 OS.