In case you're wondering, this is a proper review, not an April Fools' prank.
The Core i9-12900KS "Alder Lake" is a Special Edition processor SKU by Intel positioned at the very top of its desktop processor lineup. Intel has been doing such unconventional releases for the past few generations, including the Core i7-8086K and Core i9-9900KS. There were no such SKUs in the 10th and 11th generations, probably because Intel felt AMD had an unassailable performance lead both in gaming and productivity performance at the time. We're still in the thick of the golden era of PC processor competition between Intel and AMD with Ryzen and Core trying to win over the hearts of users.
Intel already holds the gaming performance crown with the Core i9-12900K, and its multi-threaded productivity performance is right in the league of 12-core and 16-core Ryzen 9 5000 "Zen 3" processors. What probably pushed Intel to come up with the i9-12900KS is AMD's June 2021 announcement of the 3D Vertical Cache technology followed by January 2022 claims that the new Ryzen 7 5800X3D, the first processor with this tech, is the "world's best gaming processor," catching up to the i9-12900K in gaming despite being based on the old "Zen 3" architecture and DDR4. Of course, Intel's response was to cook up a faster version of the i9-12900K, and we hence have the i9-12900KS for review today.
Architecturally and feature-wise, the Core i9-12900KS is mostly identical to the i9-12900K. You get eight "Golden Cove" performance cores (or P-cores), eight efficiency cores (or E-cores), 30 MB of shared L3 cache, an Xe LP iGPU with 32 EUs, and next-generation I/O that features PCI-Express Gen 5 and DDR5 memory while maintaining backwards-compatibility with DDR4. The higher-clocked P-cores are new, and these impact gaming performance. The P-cores now come with a maximum boost frequency of 5.50 GHz instead of the 5.20 GHz on the i9-12900K.
This is achieved with the re-introduction of the Thermal Velocity Boost feature that was rudimentary in the i9-12900K. The "KS" has a P-core base frequency of 3.40 GHz, which is 3.20 GHz on the i9-12900K. Turbo Boost 2.0 is 100 MHz higher at 5.20 GHz vs. 5.10 GHz. Turbo Boost Max 3.0 is again 100 MHz higher, at 5.30 GHz vs. 5.20 GHz. 5.20 GHz is where the i9-12900K topped out at stock settings. The i9-12900KS leverages Thermal Velocity Boost to push the P-core frequency up to 5.50 GHz. This algorithm works in the same manner as on the i9-11900K or i9-10900K, by rewarding good CPU cooling with those extra turbo bins. The E-core base and turbo frequencies get a 100 MHz uplift, too. iGPU clock speeds are unchanged. These higher clock speeds come at a slight increase in the processor base power (PBP) value, which is now 150 W compared to 125 W on the i9-12900K. The maximum turbo power (MTP), however, is identical between the two chips, at 241 W. Just like the Core i9-12900K, the 12900KS runs at PL1=PL2=241 W.
Besides Thermal Velocity Boost, the Intel Adaptive Boost Technology (ABT) makes a comeback. ABT was introduced with the i9-11900K "Rocket Lake," but was not included with the i9-12900K. ABT opportunistically enables additional boost frequency bins across all P-cores, improving multi-threaded performance.
As mentioned earlier, the Core i9-12900KS is a "Special Edition" SKU. Its retail availability won't be as widespread as the i9-12900K. Intel is pricing the chip at US$739 for 1K quantities, a $140 premium over the i9-12900K. We're using a $750 price point for calculations in this review. In return, you're promised the "world's fastest desktop processor." We're here to find out if that's the case.