Chinese reviewers certainly do not have trouble locating Raptor Lake CPUs from Intel which have not yet been launched. A pre-production sample of Intel's Core i5-13600K was obtained by Enthusiastic Citizen (ECSM). 

The Engineering Sample 3 has been designed to operate at the same frequency as QS (Qualification Sample). Unfortunately, there is no image of the CPU itself, reports videocardz. To better match QS sample requirements, the CPU was tested using a modified clock setup. The ES3's performance cores are supposed to operate at 5.1/4.9 GHz, while the Efficient cores run at 3.9 GHz. The QS raises these frequencies somewhat. ECSM put the CPU through its paces by running all of its Performance cores at 5.1 GHz and all of its Efficient cores at 4.0 GHz. To refresh your memory, the i5-13600K is reported to feature six performance cores and eight efficient cores. This equates to 14 cores and 20 threads, which is an upgrade over the Alder Lake i5-1260010 K's cores and 16 threads.

The 12600K's boost power limit (PL2) is set at 150W, but the 13600K's is higher (some reports suggest 228W). The CPU attained a maximum CPU package power of 176W in real-world testing, although the leaker believes the final unit will be tuned for 160W. The CPU voltage was said to be 1.31V.

The i5-13600K scores 830 in the single-core CPU-Z (R23) test and 10031 in the multicore benchmark. For a 12600K's 768 and 5590 points, or +8 and +79 percent, respectively, for multi-core performance.  The i5-13600K scores 1387 points in the Cinebech R23 single-core test and 24420 points in the multi-core test. This is a 40% improvement for multicore but a 26% decrease for single-core. 

Intel Core i5-13600K ES3 Raptor Lake 14-core CPU tested