Ryzen 9 3900X vs Intel Core i9-12900K — Specs & Performance Compared

Verdict: The Intel Core i9-12900K is ahead of the Ryzen 9 3900X on all 6 shared benchmarks on file, by 27% to 88%, including 53% in Cinebench R23 single (2,004 vs 1,312).

Side-by-side CPU comparison of the Ryzen 9 3900X and the Intel Core i9-12900K. Released 2019 (Ryzen 9 3900X), 2021 (Intel Core i9-12900K). MSRP range: $499 · $589. Specs, synthetic benchmarks, AI inference tok/s, and Amazon availability below; each column header links to that part's benchmark page.

AMD

Ryzen 9 3900X

12 cores105W TDP$499 MSRP2019

Full Ryzen 9 3900X benchmarks →

Intel · Alder Lake

Intel Core i9-12900K

16 cores125W TDP$589 MSRP2021

Full Intel Core i9-12900K benchmarks →

*Price sourced from Amazon.com. Price and availability subject to change.

Where to buy

A listing for each part; the current price and stock are on the retailer's page.

Specs side-by-side

Spec	Ryzen 9 3900X	Intel Core i9-12900K
cores	12	16
threads	24	24
p cores	—	8
e cores	—	8
base clock ghz	3.8	3.2
boost clock ghz	4.6	—
tdp w	105	125
l2 cache mb	—	14
l3 cache mb	64	30
process nm	7	—
socket	AMD Socket AM4	LGA1700

Synthetic benchmarks

Each row says whether a higher or a lower number is better (ranks and times are lower-is-better). Scores come from CGDirector, GadgetVersus, Notebookcheck, TechSpot, technical.city, NanoReview, Geekbench Browser, PassMark and HWBOT; each row links its sources, and where they differ the cell shows their median. Empty cells mean we don't yet have that benchmark on file for the SKU.

Benchmark	Ryzen 9 3900X	Intel Core i9-12900K
Cinebench R23 multi (higher is better) Source: CGDirector, GadgetVersus, Notebookcheck, TechSpot	18,682 points	27,392 points
Cinebench R23 single (higher is better) Source: CGDirector, GadgetVersus, Notebookcheck, TechSpot	1,312 points	2,004 points
Geekbench 6 multi (higher is better) Source: GadgetVersus, technical.city, NanoReview, Geekbench Browser	9,259 points	17,450 points
Geekbench 6 single (higher is better) Source: GadgetVersus, technical.city, NanoReview, Geekbench Browser	1,682 points	2,715 points
PassMark CPU Mark (higher is better) Source: PassMark	32,491 points	41,122 points
PassMark single thread (higher is better) Source: PassMark	—	4,128 points
PassMark Single Thread (higher is better) Source: PassMark	2,702 points	—
PassMark Single Thread Rating (higher is better) Source: PassMark	2,702 points	4,128 points
Y-cruncher Pi 1B (lower is better) Source: HWBOT	89 seconds	—

Quick answers

Which is faster, the Ryzen 9 3900X or the Intel Core i9-12900K?

The Intel Core i9-12900K is ahead of the Ryzen 9 3900X on all 6 shared benchmarks on file, by 27% to 88%, including 53% in Cinebench R23 single (2,004 vs 1,312).

What did the Ryzen 9 3900X and the Intel Core i9-12900K cost at launch?

The Ryzen 9 3900X launched at a $499 MSRP and the Intel Core i9-12900K at $589. Street prices drift from launch pricing; the Where to buy section links current listings.