Intel Core i9-12900KF vs Intel Core Ultra 7 356H Comparison

Head-to-Head Benchmarks

The recorded data shows a decisive overall win for the Intel Core i9-12900KF, which takes 15 of the 17 head-to-head benchmarks. The two processors are close in overall standing, with the i9-12900KF at the 88th percentile of all CPUs and the Core Ultra 7 356H at the 87th, and their average benchmark scores differ by only 1615 points (42830 vs 41215). Yet the individual test results reveal a much wider gap in specific workloads.

The largest victory for the i9-12900KF comes in Cinebench R23 single-core, where it scores 4859 against the Ultra 7's 2040, a 138.2% advantage. This is the single biggest delta in the entire comparison. The multi-core version of the same test shows an 87.1% lead, with the i9-12900KF scoring 34420 versus 18395. Cinebench R15 single-core also favors the desktop chip heavily, with a 61.4% margin (489 vs 303).

Integer math is another area of clear dominance. The i9-12900KF scores 138932 in PassMark integer math, which is 67.2% ahead of the Ultra 7's 83111. Data compression shows a 60% lead (537785 vs 336177), and random string sorting is 39.5% ahead (57177 vs 40990). The desktop processor also wins in multithread performance, scoring 40970 versus 33978, a 20.6% margin.

The Ultra 7 356H does claim two wins, and they are notable for their specificity. In PassMark find prime numbers, it scores 327 against the i9-12900KF's 142, a 56.6% advantage. The mobile chip also wins PassMark physics, scoring 2895 against 2098, a 27.5% lead. These are the only two tests where the Ultra 7 comes out on top.

Some benchmarks are much closer than the overall trend suggests. PassMark floating point math shows only a 2.4% difference, with the i9-12900KF at 105558 and the Ultra 7 at 103128. PassMark single-thread performance is nearly tied, with the desktop chip at 4144 and the mobile chip at 4072, a 1.8% margin. Data encryption is similarly close, with the i9-12900KF leading by 12% (29502 vs 26345). Extended instructions favor the desktop part by 21.1% (33779 vs 27898).

Cinebench R20 results fall between the extremes. Multi-core shows a 19% lead for the i9-12900KF (14456 vs 12153), and single-core shows the same 19% margin (2040 vs 1715). Cinebench R15 multi-core is a 13.6% win for the desktop chip (3469 vs 3055).

Where Each One Wins

The Intel Core i9-12900KF is the clear choice for rendering, content creation, and compute-heavy tasks. Its Cinebench results across all three versions (R15, R20, R23) show substantial leads in both single-core and multi-core workloads. The 87.1% margin in R23 multi-core and the 138.2% margin in R23 single-core indicate that the desktop processor has a decisive advantage in CPU-bound rendering workloads.

The i9-12900KF also wins in most PassMark productivity tests. Data compression, integer math, multithread, random string sorting, and extended instructions all favor the desktop chip. These results point to strong performance in database operations, file compression, and general productivity software that uses integer arithmetic.

The Intel Core Ultra 7 356H wins in two specific areas. The first is prime number finding, where it scores more than double the i9-12900KF. This suggests an advantage in workloads that rely heavily on prime number generation, such as certain encryption or mathematical applications. The second win is in physics calculations, where the Ultra 7 scores 27.5% higher. This could benefit physics simulation or gaming workloads that use CPU-based physics processing.

For users who need floating point math, the choice is nearly indifferent. The i9-12900KF leads by only 2.4%, making this the closest head-to-head result. Similarly, single-thread performance in PassMark is almost identical, with a 1.8% difference. The Ultra 7's lower power envelope of 25 watts TDP, compared to the i9-12900KF's 125 watts, suggests it may be more suitable for sustained mobile workloads despite its lower scores in most tests.

Architecture Differences

The two processors come from different generations and target different market segments. The Intel Core i9-12900KF is a desktop processor from the Core 12th Gen series, built on Alder Lake architecture with the Alder Lake-S codename. It uses a 10 nm process node and sits in an Intel Socket 1700. The Core Ultra 7 356H is a mobile processor from the Core Ultra Series 3, built on Panther Lake architecture with the Panther Lake codename. It uses a 3 nm process node and sits in an Intel BGA 2540 socket.

Both processors have 16 cores, but the thread counts differ. The i9-12900KF supports 24 threads, while the Ultra 7 356H supports 16 threads. This difference explains much of the multi-core performance gap, as the desktop chip can process more threads simultaneously.

Cache configurations also differ significantly. The i9-12900KF has 80 KB of L1 cache per core, 1.25 MB of L2 cache per core, and 30 MB of shared L3 cache. The Ultra 7 356H has 192 KB of L1 cache per core, 2.5 MB of L2 cache per core, and 18 MB of shared L3 cache. The mobile chip has larger per-core L1 and L2 caches but a smaller L3 pool.

Clock speeds favor the desktop processor. The i9-12900KF has a base clock of 3.20 GHz and a boost clock of 5.20 GHz. The Ultra 7 356H has a base clock of 1.90 GHz and a boost clock of 4.70 GHz. The higher boost clock on the desktop chip contributes to its single-core performance advantage.

Memory support differs as well. The i9-12900KF supports DDR4 and DDR5 memory over a dual-channel bus. The Ultra 7 356H supports DDR5 and LPDDR5X, also over a dual-channel bus, and has a recorded memory bandwidth of 115.2 GB/s. The desktop chip does not have a recorded memory bandwidth figure in the data.

PCIe support is another differentiator. The i9-12900KF offers Gen 4 with 20 lanes (CPU only), while the Ultra 7 356H offers Gen 5 with 12 lanes (CPU only). The mobile chip also includes integrated Intel Xe3 Graphics, whereas the i9-12900KF has no integrated graphics listed.

The i9-12900KF has an unlocked multiplier, making it suitable for overclocking. The Ultra 7 356H does not have an unlocked multiplier. The desktop chip launched on November 3, 2021, with a launch MSRP of $564. The Ultra 7 356H has a release date of January 4, 2026, and no launch MSRP is recorded.

The Verdict

The data indicates that the Intel Core i9-12900KF is the stronger processor for most workloads. Its 15 head-to-head wins, including massive margins in Cinebench R23 (87.1% multi-core, 138.2% single-core) and integer math (67.2%), make it the clear choice for rendering, productivity, and compute-heavy applications. Its average benchmark score of 42830 places it just 0.2% behind the Intel Core i9-12900 and 1.2% ahead of the Intel Core i9-12900K, showing it sits firmly in the upper tier of desktop processors.

The Intel Core Ultra 7 356H should be chosen by users who prioritize prime number calculations or physics simulation. Its 56.6% win in find prime numbers and 27.5% win in physics are the only areas where it outperforms the desktop chip. However, its 87th percentile standing and average score of 41215 show it is still a capable processor overall, just not competitive with the i9-12900KF in most tests.

Users who need a processor with lower power consumption will find the Ultra 7 356H's 25 watt TDP attractive compared to the i9-12900KF's 125 watts. The mobile chip also offers integrated graphics, which the desktop chip lacks. But for pure CPU performance, the i9-12900KF wins in 15 of 17 benchmarks, including all Cinebench tests and most PassMark tests.

The nearly identical PassMark single-thread scores (4144 vs 4072) and floating point math scores (105558 vs 103128) suggest that for light, single-threaded tasks, the difference is minimal. The i9-12900KF's advantage grows as workloads become more multi-threaded or more demanding on integer math.

FAQ

Q: Which processor has a higher single-core benchmark score?

A: The Intel Core i9-12900KF scores 4859 in Cinebench R23 single-core, while the Core Ultra 7 356H scores 2040. The desktop chip leads by 138.2% in this test.

Q: Are there any benchmarks where the Core Ultra 7 356H wins?

A: Yes, the Ultra 7 356H wins two benchmarks. It scores 327 in PassMark find prime numbers versus 142 for the i9-12900KF, a 56.6% advantage. It also wins PassMark physics with 2895 against 2098, a 27.5% margin.

Q: How do their average benchmark scores compare?

A: The i9-12900KF has an average benchmark score of 42830, while the Ultra 7 356H has 41215. This is a difference of 1615 points in favor of the desktop chip.

Q: What are the thread counts for each processor?

A: The i9-12900KF has 24 threads, while the Ultra 7 356H has 16 threads. Both have 16 cores.

Q: Which processor has a higher boost clock?

A: The i9-12900KF has a boost clock of 5.20 GHz. The Ultra 7 356H has a boost clock of 4.70 GHz.

Q: What is the TDP difference between the two?

A: The i9-12900KF has a TDP of 125 watts. The Ultra 7 356H has a TDP of 25 watts.

Specification Differences

| Specification | Intel Core i9-12900KF | Intel Core Ultra 7 356H |

|---|---|---|

| Series | Core 12th Gen | Core Ultra Series 3 |

| Threads | 24 | 16 |

| Base Clock | 3.20 GHz | 1.90 GHz |

| Boost Clock | 5.20 GHz | 4.70 GHz |

| TDP | 125 W | 25 W |

| Socket | Intel Socket 1700 | Intel BGA 2540 |

| Architecture | Alder Lake | Panther Lake |

| Codename | Alder Lake-S | Panther Lake |

| Process Node | 10 nm | 3 nm |

| Die Size | 215 mm² | Not recorded |

| L1 Cache | 80 KB (per core) | 192 KB (per core) |

| L2 Cache | 1.25 MB (per core) | 2.5 MB (per core) |

| L3 Cache | 30 MB (shared) | 18 MB (shared) |

| Memory Support | DDR4, DDR5 | DDR5, LPDDR5X |

| Memory Bandwidth | Not recorded | 115.2 GB/s |

| PCIe | Gen 4, 20 Lanes (CPU only) | Gen 5, 12 Lanes (CPU only) |

| Integrated Graphics | None | Intel Xe3 Graphics |

| Market Segment | Desktop | Mobile |

| Release Date | 2021-11-03 | 2026-01-04 |

| Launch MSRP | $564 | Not recorded |

| Multiplier Unlocked | Yes | No |

| Part Number | SRL4J | SA4RGQ9EU |