Intel Core Ultra 5 338H vs Intel Core Ultra 7 255H Comparison

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Core Ultra 5 338H records an average benchmark score of 33989, while the Intel Core Ultra 7 255H scores 33537. The Ultra 5 338H also sits at the 84th percentile among all CPUs, compared to the 83rd percentile for the Ultra 7 255H.

Q: How do the two chips compare in Cinebench multi-core tests?

A: The Ultra 5 338H dominates in multi-core Cinebench workloads. It leads by 65.3% in R15 multi-core (2504 vs 1515), by 60.1% in R20 multi-core (10213 vs 6381), and by 76.7% in R23 multi-core (16331 vs 9240).

Q: Which processor wins in PassMark integer and floating-point math?

A: The Ultra 7 255H takes both. It scores 77975 in integer math versus 64934 for the Ultra 5 338H, a 16.7% advantage. In floating-point math, the Ultra 7 255H scores 98796 versus 84067, a 14.9% lead.

Q: Are there any workloads where the Ultra 5 338H wins despite having fewer cores?

A: Yes. The Ultra 5 338H wins in Cinebench single-core tests across all three versions, leads in PassMark physics (2697 vs 2254, a 19.7% margin), and edges ahead in extended instructions (23906 vs 23755) and prime number finding (304 vs 303).

Q: What are the core and thread counts for each processor?

A: The Ultra 5 338H has 12 cores and 12 threads. The Ultra 7 255H has 16 cores and 16 threads. Neither processor supports Hyper-Threading, as threads equal cores in both cases.

Q: Which processor supports ECC memory?

A: Only the Ultra 7 255H supports ECC memory. The Ultra 5 338H does not. Both support LPDDR5X memory, but the Ultra 7 255H additionally supports DDR5.

Where Each One Wins

The benchmark data splits these two processors into distinct usage profiles. The Ultra 5 338H is the clear winner in CPU-intensive rendering and physics workloads. It wins 9 of the 17 head-to-head comparisons, with its largest margins coming in multi-core Cinebench tests. The R23 multi-core result is particularly decisive: the Ultra 5 338H leads by 76.7%, a massive gap that suggests it is the better choice for video rendering, 3D modeling, and other tasks that scale heavily with sustained multi-core performance.

The Ultra 7 255H, despite losing the overall average score battle, wins 8 of the 17 comparisons. Its victories are concentrated in PassMark workloads that favor memory bandwidth and higher boost clocks. It wins data compression (298850 vs 276539), data encryption (23395 vs 21367), floating-point math, integer math, multithread, random string sorting, and single-thread tests. The single-thread win (4317 vs 4180) is notable because it indicates the Ultra 7 255H has a slight edge in lightly threaded, latency-sensitive applications.

For everyday productivity tasks like spreadsheet calculations, file compression, and encryption, the Ultra 7 255H is the stronger candidate. For rendering, physics simulation, and Cinebench-style workloads, the Ultra 5 338H is the clear pick. The PassMark multithread score (30703 vs 28717) shows the Ultra 7 255H has a 6.5% advantage in general parallel throughput, but the Cinebench results tell a different story. This divergence suggests the Ultra 5 338H is better optimized for specific rendering instructions, while the Ultra 7 255H excels in broader, mixed integer workloads.

Architecture Differences

The two processors come from different Intel architectures. The Ultra 5 338H is built on Panther Lake, part of the Core Ultra Series 3, while the Ultra 7 255H uses Arrow Lake, from the Core Ultra Series 2. Both use a 3 nm process node, but the foundry differs: Intel fabricates the Panther Lake chip at its own fabs, while TSMC produces the Arrow Lake silicon.

Cache hierarchies differ in the L2 and L3 levels. Both chips have 192 KB of L1 cache per core, but the Ultra 5 338H has 2.5 MB of L2 per core versus 3 MB per core on the Ultra 7 255H. The shared L3 cache is also larger on the Ultra 7 255H: 24 MB versus 18 MB. This 6 MB L3 difference partially explains why the Ultra 7 255H wins in data compression and encryption, workloads that benefit from larger caches.

Memory support differs as well. The Ultra 5 338H supports only LPDDR5X, while the Ultra 7 255H supports both DDR5 and LPDDR5X. The memory bandwidth figures are counterintuitive: the Ultra 5 338H records 136.5 GB/s, which is higher than the 102.4 GB/s of the Ultra 7 255H. ECC memory support is exclusive to the Ultra 7 255H.

PCIe connectivity shows a substantial difference. The Ultra 5 338H provides Gen 5 with only 4 lanes (CPU only), while the Ultra 7 255H provides Gen 5 with 20 lanes (CPU only). This gives the Ultra 7 255H significantly more headroom for discrete GPUs and high-speed storage expansion.

Integrated graphics also differ. The Ultra 5 338H pairs with Arc B370 graphics, while the Ultra 7 255H uses Arc Graphics 140T. The sockets are different as well: the Ultra 5 338H uses Intel BGA 2540, and the Ultra 7 255H uses Intel BGA 2049.

Specification Differences

The two processors differ on several key specification fields. Core count differs by four: 12 cores and 12 threads on the Ultra 5 338H versus 16 cores and 16 threads on the Ultra 7 255H. Base clocks are close, with the Ultra 5 338H at 1.90 GHz and the Ultra 7 255H at 2.00 GHz. Boost clocks show a larger gap: 4.70 GHz versus 5.10 GHz.

Thermal design power differs by 3 watts. The Ultra 5 338H has a TDP of 25 watts, while the Ultra 7 255H has a TDP of 28 watts. Both are mobile parts with active production status, and neither has an unlocked multiplier.

Memory bandwidth is higher on the Ultra 5 338H at 136.5 GB/s versus 102.4 GB/s on the Ultra 7 255H. ECC support is present only on the Ultra 7 255H. PCIe lane count is 4 on the Ultra 5 338H versus 20 on the Ultra 7 255H, both Gen 5.

Cache allocation differs as noted: L2 per core is 2.5 MB versus 3 MB, and L3 shared is 18 MB versus 24 MB. Release dates differ by roughly one year. The Ultra 7 255H launched on January 12, 2025, while the Ultra 5 338H launched on January 4, 2026. Part numbers are SA4REQ9EW for the Ultra 5 338H and SRQAN for the Ultra 7 255H.

Head-to-Head Benchmarks

The biggest win for the Ultra 5 338H appears in Cinebench R23 multi-core, where it scores 16331 versus 9240 for the Ultra 7 255H, a 76.7% advantage. This is the single largest delta in the entire comparison. The R15 multi-core test shows a 65.3% lead (2504 vs 1515), and the R20 multi-core test shows a 60.1% lead (10213 vs 6381). These three results indicate that the Ultra 5 338H has a fundamental architectural advantage in rendering workloads, despite having four fewer cores.

Single-core Cinebench results also favor the Ultra 5 338H. In R15 single-core, it scores 305 versus 251, a 21.5% lead. In R20 single-core, it scores 1441 versus 900, another 60.1% advantage. The R23 single-core margin is narrower at 10.9% (2044 vs 1843). The large R20 single-core gap is striking and suggests the Ultra 5 338H has superior per-core performance in certain instruction paths.

The Ultra 7 255H counters with strong PassMark results. Its best win is in integer math, where it scores 77975 versus 64934, a 16.7% lead. Floating-point math shows a 14.9% advantage (98796 vs 84067). Data compression is 7.5% higher on the Ultra 7 255H (298850 vs 276539), and data encryption is 8.7% higher (23395 vs 21367). The multithread score favors the Ultra 7 255H by 6.5% (30703 vs 28717), and random string sorting is 5.5% higher (36058 vs 34082).

The single-thread PassMark result goes to the Ultra 7 255H, but only by 3.2% (4317 vs 4180). In the remaining tests, the Ultra 5 338H wins physics by 19.7% (2697 vs 2254), extended instructions by 0.6% (23906 vs 23755), and prime number finding by 0.3% (304 vs 303).

The win count is nearly even: 9 for the Ultra 5 338H and 8 for the Ultra 7 255H. However, the magnitude of the Ultra 5 338H wins is larger overall. The average benchmark score reflects this asymmetry, with the Ultra 5 338H at 33989 versus 33537 for the Ultra 7 255H. In the nearest rival comparison, the Ultra 5 338H sits within 0.7% of the AMD EPYC 4244P and within 0.3% of the Intel Core i7-12800HX. The Ultra 7 255H is essentially tied with the AMD Ryzen 5 240 (0% delta) and trails the AMD Ryzen 7 8840HS by 0.4%.