Architecture

The "Raptor Lake" microarchitecture is the swansong of monolithic silicon client processors for Intel. Future generations will implement the IDM 2.0 product design, and will be multi-chip modules with chiplets built across various foundry nodes. The "Raptor Lake" silicon is fabricated on the same Intel 7 (10 nm Enhanced SuperFin) foundry node as the previous-gen "Alder Lake," although Intel claims to have squeezed out a handful ofprovements, such as better electron channel mobility, which can let both the P-cores and E-cores gain increases in clock speeds by as much as 600 MHz over the previous-generation, and minimally higher power. The transistor-density is unchanged, since it's the same the node. The "Raptor Lake" die measures 23.8 mm x 11.8 mm (257 mm² die-area).


The channel mobility improvements on the Intel 7 node in particular lets the chip designers raise the V/F curve, with over 50 mV reduction in iso-frequency (voltage needed for frequency); over 200 MHz iso-voltage (frequency increase at a given voltage); which enables up to 600 MHz increase in Turbo Boost frequencies, with the increase of maximum turbo power (MTP) to as high as 253 W for the Core i9-13900K and i7-13700K; and as high as 181 W for the Core i5-13600K.

The "Raptor Cove" performance cores (P-cores) come with increased IPC, and while the company didn't specify the IPC gain over the previous-generation "Golden Cove" P-core, it mentions an over 15% single-threaded performance uplift. The ISA of the "Raptor Cove" core is identical to that of "Golden Cove," but the company has enhanced the hardware prefetcher dealing with the dedicated L2 cache. Helping the P-core performance uplift are the node improvements that help it sustain higher frequencies, and larger dedicated L2 cache—now 2 MB compared to 1.25 MB for "Golden Cove." The i9-13900K and i7-13700K get eight "Raptor Cove" P-cores, which come with HyperThreading enabled, so 16 threads from the P-cores. The Core i5-13600K gets six of these P-cores, for 12 threads.


The "Gracemont" E-cores are architecturally unchanged from "Alder Lake," but are tuned with higher frequencies, and the most important hardware-level change is the L2 cache. Groups of four E-cores are organized as E-core clusters, which share an L2 cache among the cores. Intel doubled this cache size from 2 MB on "Alder Lake" to 4 MB. Much like the P-cores, Intel has updated the L2 cache prefetcher algorithm for E-core clusters. The "Raptor Lake" silicon physically features four E-core clusters, so 16 E-cores in total. The Core i7-13700K is carved out by disabling two of these clusters, giving you eight E-cores; while the i5-13600K is designed by disabling two E-core clusters, as well as two P-cores, for its 6P+8E configuration.


Intel made several other updates to the cache and memory sub-system besides the enlarged L2 caches mentioned above. The shared L3 cache is now as large as 36 MB for the Core i9 SKUs, 30 MB for the Core i7 SKUs, and 24 MB for the Core i5 K/KF SKUs. The Ring Bus interconnect continues to be the town-square for this silicon, and Intel has increased its frequency by 900 MHz, now up to 5.00 GHz (it ran up to 4.10 GHz on the i9-12900K). The new Dynamic INI (inclusive/non-inclusive) architecture lets components reserve portions of the L3 cache to themselves to minimize cache misses or DRAM roundtrips if the cache is saturated. The processor supports dual-channel DDR5 and DDR4 memory types (2x 64-bit channels in case of DDR4, 4x 32-bit sub-channels in case of DDR5). The chip now supports DDR5-5600 natively (JEDEC spec), while the native DDR4 frequency is unchanged at DDR4-3200.


While it didn't put out detailed architectural block-diagrams of its CPU cores like it did the last time, Intel was kind enough to give us a breakdown of how it achieved its claimed 15% single-threaded performance uplift, and >40% multi-threaded uplift. Generational increases to frequency, cache size and prefetcher improvements, and and memory frequency uplifts, add to these. Multi-threaded performance uplift rides on the back of all these; plus the doubling in E-core count. Contributing to not just multi-threaded performance, but also consistency in multi-threaded performance across applications, are a series of updates to Intel Thread Director, the hardware-level middleware that makes Intel's Hybrid architecture work with software, by directing the right kind of workload to the right kind of CPU cores. It collaborates with OS scheduler improvements of Windows 11 22H2, particularly with smarter QoS (performance outlay) for background tasks.


All processor models being launched today are Unlocked K (or KF) SKUs, letting you go to town with overclocking. While there are no new overclocking handles with "Raptor Lake," Intel improved the software side of things, by giving Extreme Tuner Utility (XTU) new per-core multiplier settings for both the P-cores and E-cores; and a simplified UI for automated overclocking, with Speed Optimizer.

Intel Z790 Chipset

Alongside the six 13th Gen K-series processors SKUs, Intel is debuting the Z790 chipset. Motherboards based on this are guaranteed to come with out-of-the-box support for 13th Gen processors, even though 600-series chipset motherboards support them via a BIOS update, and many of them feature USB BIOS Flashback. The Z790 sees a rebalancing of the downstream PCIe connectivity in favor of more downstream Gen 4 PCIe lanes, compared to the previous-gen Z690. You will find Z790 motherboards with DDR5 memory support, as well as those with DDR4 support—Intel hasn't restricted motherboard vendors from doing so.