Intel Core Ultra 5 250K Plus vs Intel Core Ultra 7 366H Comparison

Head-to-Head Benchmarks

The recorded data shows a decisive overall victory for the Intel Core Ultra 5 250K Plus, which wins 15 of the 17 head-to-head comparisons. Its most dominant areas are memory-intensive and multi-threaded workloads. In PassMark data compression, the desktop part scores 568721 versus 327455 for the mobile chip, a 73.7% advantage. Random string sorting shows a similar gap at 73.5% (69090 versus 39814). Encryption is 63.1% ahead (42144 versus 25845), and extended instructions lead by 65.7% (44565 versus 26901). These are the widest margins in the dataset.

Multi-core rendering also favors the Ultra 5 250K Plus substantially. In Cinebench R15 multicore, it scores 4640 versus 2870, a 61.7% lead. Cinebench R20 multicore shows a 54.2% gap (18442 versus 11960), and PassMark multithread is 54.3% ahead (51596 versus 33429). The Cinebench R23 multicore margin narrows considerably to 8.4% (30867 versus 28477), indicating that the mobile chip closes ground in sustained all-core workloads. Integer math (49.5% lead, 125091 versus 83695) and floating-point math (57% lead, 162692 versus 103615) reinforce the desktop part's arithmetic superiority. Prime number search is 49.1% faster (486 versus 326), while physics simulation shows a more modest 21.3% advantage (3494 versus 2880).

The Intel Core Ultra 7 366H takes only two wins, both in Cinebench single-core tests. In Cinebench R15 single-core, the mobile chip scores 405 versus 328, a 19% advantage. The gap widens dramatically in Cinebench R23 single-core, where the Ultra 7 366H scores 4020 versus 2261, a 43.8% lead. However, the PassMark single-thread test tells a different story: the Ultra 5 250K Plus wins there with 4757 versus 4043, a 17.7% margin. This contradiction between Cinebench R23 single-core and PassMark single-thread suggests the two CPUs have very different microarchitectural strengths, with the Ultra 7 366H excelling specifically in the Cinebench rendering workload while the desktop part is faster in general single-threaded operations.

The overall average benchmark score reflects the same split: the Ultra 5 250K Plus averages 66855 across all tests, while the Ultra 7 366H averages 41263. The desktop part sits at the 93rd percentile of all CPUs, the mobile chip at the 87th.

Where Each One Wins

The Ultra 5 250K Plus is the clear choice for any workload that scales with core count, cache size, or memory bandwidth. Its 18 cores versus 16, plus a 30 MB shared L3 cache versus 18 MB, explain the consistent 50% to 70% leads in compression, encryption, sorting, and instruction-heavy workloads. The 115.2 GB/s memory bandwidth is identical between the two, so the differences in these tests come from core architecture and cache hierarchy, not memory throughput.

Data compression, encryption, and random string sorting are the Ultra 5's strongest categories, with all three exceeding 60% deltas. These are classic multi-threaded, memory-latency-sensitive tasks. The 3 MB per-core L2 cache on the Ultra 5 versus 2.5 MB per-core on the Ultra 7 contributes to its sorting and compression advantages. For rendering, the Cinebench R23 multicore result (8.4% delta) is the closest contest, suggesting that the Ultra 7 366H's Panther Lake architecture handles sustained all-core AVX-style loads relatively efficiently despite its 25 W TDP.

The Ultra 7 366H wins in Cinebench R15 single-core and Cinebench R23 single-core, both by large margins (19% and 43.8% respectively). This points to a very strong single-threaded core design in the Panther Lake architecture. The 4.80 GHz boost clock is lower than the Ultra 5's 5.30 GHz, yet it still wins decisively in these rendering single-core tests. The PassMark single-thread result contradicts this, however, with the Ultra 5 winning by 17.7%. That discrepancy means the Ultra 7's single-core advantage is not universal; it applies specifically to Cinebench's rendering workload rather than to all single-threaded activity.

For physics simulation (PassMark physics), the Ultra 5 leads by 21.3%, a moderate margin. For prime number finding, the lead is 49.1%. Both are compute-bound tasks, and the desktop chip's higher core count and larger caches drive these results. The mobile chip's two wins do not compensate for the breadth of the desktop part's advantages across the remaining 15 tests.

Architecture Differences

The two processors belong to different Intel series and generations. The Ultra 5 250K Plus is from Core Ultra Series 2, codenamed Arrow Lake Refresh, with a generation label of "Ultra 5 (Arrow Lake)". The Ultra 7 366H is from Core Ultra Series 3, codenamed Panther Lake, with a generation label of "Ultra 7 (Panther Lake-H)". They are built on the same 3 nm process node, but by different foundries: TSMC fabricates the Ultra 5, while Intel fabricates the Ultra 7.

Core and thread counts differ: 18 cores and 18 threads for the Ultra 5, versus 16 cores and 16 threads for the Ultra 7. Neither uses simultaneous multithreading. Base clocks are far apart: 4.20 GHz for the desktop part versus 2.00 GHz for the mobile part. Boost clocks are 5.30 GHz and 4.80 GHz respectively. The TDP ratings reflect their market segments: 125 W for the desktop Socket 1851 part, 25 W for the mobile BGA 2540 part. The Ultra 5 has an unlocked multiplier; the Ultra 7 does not.

Cache hierarchies differ significantly. Both have 192 KB of L1 per core. The L2 cache is 3 MB per core on the Ultra 5 versus 2.5 MB per core on the Ultra 7. The shared L3 cache is 30 MB on the Ultra 5 versus 18 MB on the Ultra 7. This 12 MB L3 difference, plus the larger per-core L2, explains the desktop part's strong showing in cache-sensitive workloads like compression and sorting.

Memory support is another differentiator. The Ultra 5 supports DDR5 only, while the Ultra 7 supports both DDR5 and LPDDR5X. Both use dual-channel memory buses with identical 115.2 GB/s peak bandwidth. ECC memory is supported on the Ultra 5 but not on the Ultra 7. PCIe lane counts differ: the Ultra 5 provides Gen 5 with 20 CPU lanes, the Ultra 7 provides Gen 5 with 12 CPU lanes. Integrated graphics differ as well: the Ultra 5 uses Arc Xe-LPG Graphics with 64 execution units, while the Ultra 7 uses Intel Xe3 Graphics. The Ultra 5 has a launch MSRP of $199; the Ultra 7 has no recorded launch MSRP. The Ultra 5's transistor count is 17,800 million on a 243 mm² die, while the Ultra 7's transistor count and die size are not recorded in the database. Release dates are close: the Ultra 5 launched on 2026-03-10, the Ultra 7 on 2026-01-04. Both are active in production.

The Verdict

The data supports a clear split by use case. The Intel Core Ultra 5 250K Plus is the stronger processor for multi-threaded desktop workloads, with leads ranging from 8.4% (Cinebench R23 multicore) to 73.7% (data compression) over the Ultra 7 366H. Its 18 cores, 30 MB L3 cache, and 125 W TDP enable this performance. The 93rd percentile ranking versus 87th for the mobile chip confirms the overall performance hierarchy. The desktop part also wins the PassMark single-thread test (17.7% lead), meaning it is not merely a multi-core specialist.

The Intel Core Ultra 7 366H is the better choice for single-core rendering workloads, specifically those measured by Cinebench R15 and R23 single-core tests. Its 19% and 43.8% leads are substantial. The 25 W TDP and BGA 2540 socket make it a mobile part, and the architecture clearly prioritizes single-thread efficiency in rendering contexts. However, the PassMark single-thread result (a 17.7% loss) tempers any claim of universal single-core superiority.

For a desktop system with an unlocked multiplier, the Ultra 5 250K Plus offers a wider performance envelope across most measured categories. For a mobile system where power draw and socket compatibility are constraints, the Ultra 7 366H delivers competitive multi-core performance (only 8.4% behind in Cinebench R23 multicore) while using far less power. The choice depends on the platform: desktop users should favor the Ultra 5, and mobile users the Ultra 7. The benchmark data does not support recommending the mobile chip for desktop-style workloads, nor the desktop chip for mobile constraints.

FAQ

Q: Which processor has more cores?

A: The Intel Core Ultra 5 250K Plus has 18 cores and 18 threads, while the Intel Core Ultra 7 366H has 16 cores and 16 threads.

Q: How large is the L3 cache difference?

A: The Ultra 5 250K Plus has 30 MB of shared L3 cache, while the Ultra 7 366H has 18 MB. The L2 cache is also larger on the Ultra 5 at 3 MB per core versus 2.5 MB per core.

Q: What is the biggest single benchmark gap between the two?

A: The largest delta is in PassMark data compression, where the Ultra 5 250K Plus scores 568721 versus 327455 for the Ultra 7 366H, a 73.7% advantage.

Q: In which tests does the Ultra 7 366H win?

A: The Ultra 7 366H wins in Cinebench R15 single-core (405 versus 328, a 19% lead) and Cinebench R23 single-core (4020 versus 2261, a 43.8% lead).

Q: Do both processors support the same memory types?

A: No. The Ultra 5 250K Plus supports DDR5 only, while the Ultra 7 366H supports both DDR5 and LPDDR5X. Both have dual-channel buses with 115.2 GB/s bandwidth.

Q: Which processor has a higher boost clock?

A: The Ultra 5 250K Plus boosts to 5.30 GHz, while the Ultra 7 366H boosts to 4.80 GHz. The base clocks are 4.20 GHz and 2.00 GHz respectively.