Intel Core i9-12900K vs Intel Core Ultra 7 366H Comparison

Head-to-Head Benchmarks

The recorded data presents a clear split between these two Intel processors. The Intel Core i9-12900K takes 12 of the 17 head-to-head benchmark wins, while the Intel Core Ultra 7 366H secures 5. The margins, however, tell a more nuanced story than the raw win count.

The i9-12900K dominates in throughput-oriented workloads. Its largest victory comes in PassMark integer math, where it scores 139090 against 83695, a 66.2% advantage. Data compression shows a similar pattern: 537341 versus 327455, a 64.1% lead. Random string sorting favors the desktop chip by 43.4% (57094 to 39814). The i9-12900K also wins Cinebench R15 multicore by 41.4% (4057 to 2870) and PassMark extended instructions by 25.2% (33682 to 26901). In multithreaded PassMark, it leads 41213 to 33429, a 23.3% margin.

The Ultra 7 366H counters in specific areas, and its wins are substantial. The most dramatic is Cinebench R23 single-core: 4020 versus 2004.5, a 50.1% advantage. That is the largest single delta in either direction across the entire comparison. Cinebench R15 single-core also favors the mobile chip, 405 to 289, a 28.6% lead. In PassMark find prime numbers, the Ultra 7 scores 326 against 147, a 54.9% advantage. PassMark physics goes to the Ultra 7 as well, 2880 to 2219, a 23% lead. Finally, Cinebench R23 multicore shows the Ultra 7 ahead at 28477 versus 26125, an 8.3% margin.

Several contests are close. PassMark floating point math is nearly even: 105471 for the i9-12900K against 103615 for the Ultra 7, only a 1.8% difference. PassMark single-thread is similarly tight at 4136 versus 4043, a 2.3% edge for the i9-12900K. Cinebench R20 splits differently: the i9-12900K wins multicore 14679 to 11960 (22.7% lead) and single-core 2072 to 1688 (22.7% lead in the opposite direction). PassMark data encryption leans i9-12900K by 14.4% (29579 to 25845).

The average benchmark scores place the two processors in nearly the same percentile tier. The i9-12900K averages 42335, sitting at the 88th percentile of all CPUs. The Ultra 7 366H averages 41263, at the 87th percentile. The i9-12900K's nearest rival, the Intel Core i9-12950HX, scores 42487 on average, a 0.4% difference. The Ultra 7 366H's closest rival, the Intel Core Ultra 7 356H, averages 41215 with a 0.1% delta. In aggregate terms, these are adjacent entries in the database's overall ranking, separated by roughly 1000 points.

Where Each One Wins

The Intel Core i9-12900K is built for sustained multi-core workloads that stress many threads simultaneously. The PassMark multithread score of 41213 sits well above the Ultra 7's 33429, and the 23.3% gap reflects the i9-12900K's 24 threads against the Ultra 7's 16 threads. Integer-heavy calculations, whether in PassMark integer math, data compression with 537341, or extended instructions at 33682, consistently favor the desktop flagship by 64.1%, 25.2%, 66.2%, and 43.4% respectively. For users processing large datasets, sorting strings at 57094, encrypting data at 29579, running Cinebench R15 multicore at 4057, or R20 multicore at 14679, the i9-12900K is the stronger choice across the board. Even in the nearer contests, the i9-12900K edges out the Ultra 7 in PassMark floating point math by 1.8% and PassMark single-thread by 2.3%, so it also retains a small lead in some moderately threaded and lighter workloads.

The Intel Core Ultra 7 366H wins where single-core efficiency or specific instruction patterns matter. Cinebench R23 single-core is its strongest territory, where 4020 more than doubles the i9-12900K's 2004.5. Cinebench R15 single-core shows a similar though smaller advantage at 405 versus 289. Prime number finding is another clear victory, 326 versus 147, and PassMark physics at 2880 versus 2219 suggests the Ultra 7 handles certain compute patterns more efficiently. Its Cinebench R23 multicore win at 28477 rounds out the picture at 8.3% ahead of the i9-12900K, an anomaly worth noting given the i9-12900K's otherwise dominant multicore profile. R20 multicore tells a different story, the i9-12900K leads by 22.7%, and R15 multicore shows a 41.4% i9-12900K lead, so within Cinebench versions the results are surprisingly inconsistent.

FAQ

Q: Which CPU wins more head-to-head benchmarks?

A: The Intel Core i9-12900K wins 12 of the 17 recorded head-to-head tests. The Intel Core Ultra 7 366H wins the remaining 5.

Q: Is the Ultra 7 stronger in single-core performance?

A: In Cinebench R23 single-core, yes, the Ultra 7 scores 4020 against 2004.5, a 50.1% lead. In Cinebench R15 single-core it leads 405 to 289. However, in PassMark single-thread the i9-12900K leads slightly at 4136 versus 4043.

Q: How do their average benchmark scores compare?

A: The i9-12900K averages 42335, while the Ultra 7 366H averages 41263. The i9-12900K sits at the 88th percentile of all CPUs, the Ultra 7 at the 87th.

Q: Which processor has better multithreaded performance?

A: The i9-12900K wins PassMark multithread by 23.3% (41213 to 33429) and Cinebench R15 multicore by 41.4% (4057 to 2870). The Ultra 7 wins Cinebench R23 multicore by 8.3% (28477 to 26125), but the i9-12900K leads in R20 multicore 14679 to 11960.

Q: What are the closest benchmark results?

A: PassMark floating point math is the tightest at 105471 for the i9-12900K versus 103615 for the Ultra 7, a 1.8% margin. PassMark single-thread is also close at 4136 to 4043, a 2.3% gap.

Q: Which processor has the larger single benchmark win?

A: The Ultra 7 366H's Cinebench R23 single-core score of 4020 is 50.1% higher than the i9-12900K's 2004.5. The i9-12900K's largest win is PassMark integer math at 66.2% over the Ultra 7.

Specification Differences

The two processors differ across nearly every hardware category. The i9-12900K has 16 cores and 24 threads, while the Ultra 7 366H has 16 cores and 16 threads. Base clocks differ: 3.20 GHz for the i9-12900K versus 2.00 GHz for the Ultra 7. Boost clocks are 5.20 GHz and 4.80 GHz respectively. Thermal design power is drastically different: 125 watts for the desktop chip, 25 watts for the mobile chip.

The socket is a fundamental split, Intel Socket 1700 for the i9-12900K and Intel BGA 2540 for the Ultra 7. Memory support differs as well: the i9-12900K supports DDR4 and DDR5, while the Ultra 7 supports DDR5 and LPDDR5X. Both are dual-channel, but memory bandwidth favors the Ultra 7 at 115.2 GB/s versus 76.8 GB/s. ECC memory is supported on the i9-12900K but not on the Ultra 7. PCIe connectivity is Gen 5 on both, but with different lane counts: 16 lanes for the i9-12900K, 12 for the Ultra 7.

Integrated graphics are different: UHD Graphics 770 for the i9-12900K, Intel Xe3 Graphics for the Ultra 7. Market segments separate them as Desktop versus Mobile. The i9-12900K has an unlocked multiplier; the Ultra 7 does not. The i9-12900K launched on 2021-11-03 with a $599 launch MSRP. The Ultra 7 366H has a launch date of 2026-01-04 and no recorded launch MSRP. Part numbers also differ: SRL4H for the i9-12900K, SA4R9Q9EL for the Ultra 7.

Architecture Differences

The i9-12900K is built on Alder Lake, specifically Alder Lake-S, using a 10 nm process from Intel's foundry. The Ultra 7 366H uses Panther Lake, the Panther Lake-H variant, on a 3 nm process, also from Intel. The die size is recorded for the i9-12900K at 215 mm², while the Ultra 7's die size is not recorded.

Cache layouts are notably different. The i9-12900K has 80 KB of L1 per core and 1.25 MB of L2 per core, with 30 MB of shared L3. The Ultra 7 has larger per-core caches: 192 KB of L1 per core and 2.5 MB of L2 per core, but a smaller 18 MB of shared L3. The generation names also differ: the i9-12900K is listed as Core i9 (Alder Lake-S), while the Ultra 7 is Ultra 7 (Panther Lake-H).

The Verdict

The data points to a workload-dependent decision. The Intel Core i9-12900K is the stronger choice for multithreaded productivity, integer math, compression, encryption, and most general-passmark tasks. Its 66.2% lead in integer math, 64.1% in data compression, 23.3% in PassMark multithread, and 22.7% in Cinebench R20 multicore make it the clear winner for heavily parallel workloads. It also edges ahead in PassMark single-thread by 2.3%, so even some lighter tasks favor it.

The Intel Core Ultra 7 366H is the pick when single-core efficiency or specific compute patterns matter more. Its 50.1% lead in Cinebench R23 single-core and 23% lead in PassMark physics show a different strength profile. The 8.3% win in Cinebench R23 multicore is notable, but it runs against the grain of the i9-12900K's other multicore victories.

The overall averages are close: 42335 for the i9-12900K, 41263 for the Ultra 7, separated by about 2.6%. The percentile ranks are adjacent at 88 and 87. The i9-12900K wins more tests and wins most of them by large margins; the Ultra 7 wins fewer but with some very large margins in its favor. For desktop users with power headroom and thread-heavy applications, the i9-12900K is the data-backed choice. For mobile users prioritizing single-core responsiveness and efficiency, the Ultra 7 366H holds the advantage.