Introduction

Intel Core i9-13900KS Raptor Lake is team-blue’s flagship desktop processor, designed to offer the highest possible gaming and application performance. It is also a Special Edition variant, which means it may not be available in all of the regions where you can normally buy the i9-13900K. The new i9-13900KS in this review is targeted squarely at the discerning PC enthusiast that wants the highest bins of Raptor Lake silicon, in a fully unlocked processor with the highest power limits, so they could chase down overclocking or benchmark leaderboards, while also being the fastest processor gamers can buy to run at stock frequencies.

The Core i9-13900KS is based on the same “Raptor Lake-S” silicon as the i9-13900K, and shares its CPU core-count of 8P+16E, which is 8 Raptor Cove performance-cores, along with 16 Gracemont efficiency cores. What’s different is that the clock speeds are dialed up, specifically for the 8 P-cores. The processor’s maximum boost frequency is 6.00 GHz, compared to 5.80 GHz for the regular i9-13900K. The classic Turbo Boost 2.0 frequency is raised by 100 MHz, from 5.5 GHz to 5.6 GHz, while the base frequency sees a slight 200 MHz bump on for the i9-13900KS, to 3.20 GHz. The E-core maximum boost frequency is unchanged at 4.30 GHz, but the E-core base frequency is a touch higher on the i9-13900KS, at 2.40 GHz compared to 2.20 GHz on the i9-13900K.

These frequency bumps may seem small, but appear to significantly change the power specs, at least on paper. The processor base power is now stepped up to 150 W, compared to 125 W for the i9-13900K, while interestingly, the maximum turbo power stays at 253 W. Intel may not list it in the specs, particularly its ARK product information page, but the i9-13900KS has a 320 W maximum turbo power mode “Extreme Power Delivery Profile” that is enabled by default in the motherboard BIOS, making it the processor’s unofficial maximum turbo power value. The higher power limits translate into better boost frequency residency compared to that of the i9-13900K, which topped out at 253 W by default.

All other specs of the new Core i9-13900KS remain the same. Each of the 8 P-cores has 2 MB of dedicated L2 cache, while each of the four E-core clusters shares a 4 MB L2 cache among its 4 cores. The P-cores and E-core clusters share a large 36 MB L3 cache along with the same Xe LP-based UHD 770 integrated graphics, and a feature-rich memory controller that supports both DDR5 and DDR4 memory types, along with on-the-fly DRAM overclocking (something competing Ryzen 7000 processors lack). The processor puts out 16 PCI-Express Gen 5 lanes that by default are assigned to the PCI-Express Graphics (PEG) slot. The CPU-attached NVMe slot still runs at PCIe Gen 4 speed, but motherboard designers have figured out ways to add Gen 5 NVMe slots by subtracting lanes from the PEG slot (something that doesn’t hurt the performance of even the fastest RTX 4090).

The Raptor Lake microarchitecture represents the final monolithic client processor silicon from Intel, which makes this review special. Future generations of Intel processors are expected to embrace chiplets. Raptor Lake promises top-dollar gaming performance thanks to its high-IPC P-cores, and multi-threaded productivity performance from its E-cores. Intel is pricing the Core i9-13900KS at $700, a $100 premium over the regular i9-13900K, but given that this is a Special Edition SKU, we’ve seen marked-up pricing on this chip. There’s only few places that have the 13900KS in-stock, with prices reaching up to $1000+, we are using $800 in our review, as you can find the KS at that price with a little bit of digging.