Intel Core Ultra 5 338H vs Intel Core Ultra 7 266V Comparison

Intel Core Ultra 5 338H and Intel Core Ultra 7 266V are both active mobile processors from Intel, yet they represent different architectural generations and design philosophies. The 338H is a Panther Lake part from the Core Ultra Series 3, while the 266V is a Lunar Lake chip from the Core Ultra Series 2. The benchmark data reveals a clear split: the 338H dominates multi-threaded and throughput workloads, while the 266V counters with superior efficiency in specific single-threaded tests. The database records 15 wins for the 338H and 2 wins for the 266V across 17 head-to-head comparisons.

Head-to-Head Benchmarks

The most lopsided result in the dataset is the PassMark physics test, where the Intel Core Ultra 5 338H scores 2697 against the Intel Core Ultra 7 266V's 1608, a 67.7% advantage. This is the largest delta in either direction and highlights a substantial gap in simulated physics processing. The 338H also leads PassMark prime number finding by 59.2%, scoring 304 versus 191, and PassMark integer math by 56.2%, with 64934 against 41558. These results indicate that the 338H's larger core count provides a decisive edge in compute-heavy integer operations.

In Cinebench R20 multicore, the 338H scores 10213 versus 6948 for the 266V, a 47% lead. Cinebench R15 multicore shows a similar pattern, with 2504 against 1667, a 50.2% gap. PassMark multithread confirms the trend, with 28717 versus 19461, a 47.6% difference. The 338H also wins PassMark data compression by 47.8% (276539 versus 187050), data encryption by 54.6% (21367 versus 13822), and extended instructions by 50.1% (23906 versus 15928). Floating point math goes to the 338H by 47.7%, with 84067 against 56923. Random string sorting favors the 338H by 48.8%, at 34082 versus 22905.

Single-threaded performance tells a more nuanced story. In Cinebench R23 singlecore, the 266V wins with 2335 against 2044, a 12.5% advantage. The 266V also takes Cinebench R23 multicore by a slim margin, 16544 versus 16331, a 1.3% difference. The 338H does win PassMark single-thread by 6%, at 4180 versus 3943, and Cinebench R15 singlecore by 29.8%, with 305 versus 235. The 338H also leads Cinebench R20 singlecore by 47%, at 1441 versus 980. The single-thread results are inconsistent across test suites, suggesting that workload characteristics matter more than raw clock speed. The 266V has a higher boost clock of 5.00 GHz against 4.70 GHz for the 338H, which may explain its Cinebench R23 singlecore win, but the 338H's higher base clock of 1.90 GHz versus 2.20 GHz does not align with the observed single-thread deltas.

Where Each One Wins

The Intel Core Ultra 5 338H wins in nearly every throughput-oriented category. It leads in Cinebench R15 and R20 multicore, PassMark multithread, data compression, data encryption, extended instructions, prime number finding, floating point math, integer math, physics, and random string sorting. This makes it the stronger choice for workloads that scale with core count, such as rendering, compression tasks, and parallel computation. The 338H's 12 cores and 12 threads, combined with 18 MB of shared L3 cache, provide a wider execution resource pool than the 266V's 8 cores and 8 threads with 12 MB of shared L3 cache.

The Intel Core Ultra 7 266V wins in Cinebench R23 multicore and Cinebench R23 singlecore. The R23 multicore win is narrow, just 1.3%, which is surprising given the 338H's dominance in other multicore tests. This may indicate that the 266V's architecture handles the specific R23 workload more efficiently per core. The R23 singlecore win is more decisive at 12.5%, suggesting that the 266V's higher boost clock of 5.00 GHz and its Lunar Lake design offer a genuine single-thread advantage in this benchmark. The 266V also has a lower TDP of 17 watts against 25 watts for the 338H, which positions it for efficiency-focused scenarios, though the data does not include direct power consumption measurements.

Architecture Differences

The two processors come from different foundries. The Intel Core Ultra 5 338H uses a 3 nm process node from Intel, while the Intel Core Ultra 7 266V uses a 3 nm process node from TSMC. Both are 3 nm, but the foundry difference reflects distinct manufacturing approaches. The 338H is built on the Panther Lake architecture, part of the Core Ultra Series 3, while the 266V uses the Lunar Lake architecture from the Core Ultra Series 2. The 338H belongs to the Ultra 5 (Panther Lake-H) generation, and the 266V is in the Ultra 7 (Lunar Lake) generation.

Core and cache configurations diverge significantly. The 338H has 12 cores and 12 threads, while the 266V has 8 cores and 8 threads. Neither processor supports simultaneous multithreading, as thread counts equal core counts for both. L1 cache is identical at 192 KB per core, and L2 cache is also identical at 2.5 MB per core. The L3 cache differs: the 338H has 18 MB shared, while the 266V has 12 MB shared. The 338H's larger L3 cache likely contributes to its lead in data compression and encryption tests, where cache capacity influences throughput.

Memory support is similar. Both use LPDDR5X memory with dual-channel buses and 136.5 GB/s memory bandwidth. The 266V's memory support is noted as dependent on the motherboard, while the 338H's is listed directly as LPDDR5X. Neither supports ECC memory. PCIe connectivity is identical: Gen 5 with 4 lanes, CPU only. Integrated graphics differ, with the 338H featuring Arc B370 and the 266V featuring Arc 140V. The 338H uses socket Intel BGA 2540, while the 266V uses Intel BGA 2833, so they are not socket-compatible. The 338H was released later, with a release date of 2026-01-04, while the 266V launched on 2024-09-23. Neither processor has an unlocked multiplier.

FAQ

Q: Which processor has more cores?

A: The Intel Core Ultra 5 338H has 12 cores and 12 threads. The Intel Core Ultra 7 266V has 8 cores and 8 threads.

Q: What is the L3 cache difference?

A: The Intel Core Ultra 5 338H has 18 MB of shared L3 cache. The Intel Core Ultra 7 266V has 12 MB of shared L3 cache.

Q: How do single-thread scores compare?

A: The Intel Core Ultra 7 266V wins Cinebench R23 singlecore with 2335 against 2044, a 12.5% lead. The Intel Core Ultra 5 338H wins PassMark single-thread with 4180 versus 3943, a 6% lead.

Q: Which processor wins Cinebench R23 multicore?

A: The Intel Core Ultra 7 266V wins with 16544 against 16331, a 1.3% margin. This is the only multicore test where the 266V leads.

Q: What are the TDP values?

A: The Intel Core Ultra 5 338H has a TDP of 25 watts. The Intel Core Ultra 7 266V has a TDP of 17 watts.

Q: Are the sockets the same?

A: No. The Intel Core Ultra 5 338H uses Intel BGA 2540. The Intel Core Ultra 7 266V uses Intel BGA 2833.

The Verdict

The data supports a clear division of roles. The Intel Core Ultra 5 338H is the throughput leader, winning 15 of 17 head-to-head comparisons, including large margins in physics, integer math, data encryption, and prime number finding. Its 12 cores, 18 MB L3 cache, and 25 watt TDP position it for multi-threaded workloads where parallel execution dominates. The average benchmark score of 33989 and the 84th percentile across all CPUs place it firmly ahead of the 266V's average of 23297 and 76th percentile.

The Intel Core Ultra 7 266V is the efficiency-oriented alternative. It wins Cinebench R23 multicore and singlecore, with the singlecore margin at 12.5%, and it does so with a lower TDP of 17 watts. Its 8 cores and 12 MB L3 cache are smaller, yet its 5.00 GHz boost clock and Lunar Lake architecture deliver a competitive single-thread result in that specific test. The 266V's nearest rival, the AMD Ryzen 7 5800H, has a delta of 0.1%, while the 338H's nearest rival, the Intel Core Ultra 7 165H, has a delta of -0.3%, meaning the 338H sits just below that rival in average score.

The choice depends on the workload profile. The 338H is the pick for heavy parallel tasks, based on its dominant multi-thread scores and higher cache capacity. The 266V suits scenarios where lower power draw and a specific single-thread edge in Cinebench R23 are priorities. The 338H's 84th percentile versus the 266V's 76th percentile reinforces the overall performance gap, but the 266V's R23 wins show that architectural efficiency can offset core count disadvantages in selected tests.

Specification Differences

| Specification | Intel Core Ultra 5 338H | Intel Core Ultra 7 266V |

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

| Cores | 12 | 8 |

| Threads | 12 | 8 |

| Base Clock | 1.90 GHz | 2.20 GHz |

| Boost Clock | 4.70 GHz | 5.00 GHz |

| TDP | 25 W | 17 W |

| Socket | Intel BGA 2540 | Intel BGA 2833 |

| Architecture | Panther Lake | Lunar Lake |

| Codename | Panther Lake | Lunar Lake |

| Generation | Ultra 5 (Panther Lake-H) | Ultra 7 (Lunar Lake) |

| Process Node | 3 nm | 3 nm |

| Foundry | Intel | TSMC |

| L3 Cache | 18 MB (shared) | 12 MB (shared) |

| Integrated Graphics | Arc B370 | Arc 140V |

| Release Date | 2026-01-04 | 2024-09-23 |

| Part Number | SA4REQ9EW | SRPMMSRPMY |

| Series | Core Ultra Series 3 | Core Ultra Series 2 |

Both processors share L1 cache at 192 KB per core, L2 cache at 2.5 MB per core, LPDDR5X memory support, dual-channel memory buses, 136.5 GB/s memory bandwidth, no ECC support, Gen 5 PCIe with 4 lanes, mobile market segment, active production status, and locked multipliers. Neither has a launch MSRP recorded in the database.