Intel Core Ultra 7 255HX vs Intel Core Ultra 9 285 Comparison

Head-to-Head Benchmarks

The benchmark data delivers a clear verdict: the Intel Core Ultra 9 285 wins every single head-to-head test against the Intel Core Ultra 7 255HX, taking all 17 recorded comparisons. The most dramatic separation appears in single-core Cinebench workloads. In Cinebench R23 single-core, the Ultra 9 285 scores 6909 against 2163 for the Ultra 7 255HX, a 68.7% advantage. Cinebench R15 single-core shows an even wider gap, with the Ultra 9 285 at 696 and the Ultra 7 255HX at 327, a 53% deficit for the latter. These single-threaded results indicate substantially higher per-core performance in the desktop part.

Multi-core performance also favors the Ultra 9 285, though by smaller margins. Cinebench R23 multi-core shows the Ultra 9 285 at 48945 versus 32612 for the Ultra 7 255HX, a 33.4% lead. Cinebench R20 multi-core delivers a 16.4% advantage (20556 versus 17187). The Cinebench R15 multi-core test is nearly a tie: 4933 for the Ultra 9 285 versus 4916 for the Ultra 7 255HX, a mere 0.3% difference. That near-parity in the older multi-core test contrasts with the much larger gaps in newer Cinebench versions, suggesting the Ultra 9 285 scales better under sustained multi-core loads.

PassMark results follow the same pattern. The Ultra 9 285 leads in PassMark multithread with 56602 against 48234, a 14.8% margin. PassMark integer math shows a 22.9% advantage (164869 versus 127126), and floating point math shows 194988 versus 160624, a 17.6% lead. Data compression favors the Ultra 9 285 by 14.4% (602121 versus 515143), while data encryption shows a 15.9% gap (46949 versus 39499). Extended instructions land at 45357 versus 41247, a 9.1% difference. The smallest PassMark margin is single-thread performance: 4881 versus 4562, a 6.5% lead for the Ultra 9 285.

Random string sorting, physics, and prime number tests all favor the Ultra 9 285. Random string sorting shows 73651 versus 62591, a 15% advantage. Physics scores 3598 versus 2926, an 18.7% gap. Find prime numbers delivers 459 versus 400, a 12.9% difference. In aggregate, the average benchmark score for the Ultra 9 285 sits at 75488, placing it in the 95th percentile of all CPUs. The Ultra 7 255HX averages 62738, sitting in the 93rd percentile. That two-percentile gap understates the performance delta, since the Ultra 9 285's nearest rivals are server-class parts like the AMD EPYC 8224P, against which it trails by only 0.1%.

Architecture Differences

Both processors belong to the Core Ultra Series 2 and share the Arrow Lake architecture, but they target different market segments. The Ultra 7 255HX is a mobile part with the Arrow Lake-HX codename, while the Ultra 9 285 is a desktop processor with the Arrow Lake-S codename. Both use TSMC's 3 nm process node and pack 17,800 million transistors on a 243 mm² die.

Core counts differ substantially. The Ultra 7 255HX provides 20 cores and 20 threads, with no hyperthreading. The Ultra 9 285 provides 24 cores and 24 threads, also without hyperthreading. Clock speeds favor the Ultra 9 285: its base clock runs at 2.50 GHz versus 2.40 GHz for the Ultra 7 255HX, and its boost clock reaches 5.60 GHz versus 5.20 GHz. The thermal design power also differs, with the Ultra 9 285 rated at 65 watts and the Ultra 7 255HX at 55 watts.

Cache allocation shows a meaningful difference in L3 capacity. Both parts use 192 KB of L1 per core and 3 MB of L2 per core, but the shared L3 cache scales with core count. The Ultra 9 285 carries 36 MB of shared L3, while the Ultra 7 255HX has 30 MB. That extra 6 MB of L3, combined with four additional cores, helps explain the Ultra 9 285's multi-core advantage.

The socket and platform differ completely. The Ultra 7 255HX uses Intel BGA 2114, a mobile socket, while the Ultra 9 285 uses Intel Socket 1851 for desktops. The Ultra 7 255HX has an unlocked multiplier, enabling overclocking on supported mobile platforms. The Ultra 9 285 has a locked multiplier. The Ultra 7 255HX carries part number SRVFG and released on 2025-01-12, while the Ultra 9 285 carries part number SRQD4 and released on 2024-12-31.

Memory support is identical in capacity but differs in ECC capability. Both support DDR5 memory with a dual-channel bus and 102.4 GB/s bandwidth. The Ultra 9 285 supports ECC memory, while the Ultra 7 255HX does not. Both processors expose PCIe Gen 5 with 20 lanes from the CPU, and both integrate the same Arc Xe-LPG Graphics 64EU solution. The Ultra 9 285 has a launch MSRP of $579, though no pricing data exists for the Ultra 7 255HX.

Where Each One Wins

The Ultra 9 285 wins every benchmark in the database, so the analysis focuses on the magnitude of its advantages and the workloads where the gap is smallest. The Ultra 7 255HX comes closest in Cinebench R15 multi-core, trailing by only 0.3%. That result suggests older multi-threaded applications that do not scale heavily with core count or cache will see near-identical performance from both parts. Single-threaded workloads show the largest separation, with the Ultra 9 285 leading by 53% in Cinebench R15 single-core and 68.7% in Cinebench R23 single-core. Applications that depend heavily on single-core speed, such as legacy games or lightly threaded productivity tools, will benefit disproportionately from the Ultra 9 285.

PassMark single-thread shows the smallest overall gap at 6.5%, indicating that the Ultra 7 255HX is not far behind in general single-threaded throughput. The Ultra 9 285's largest PassMark wins come in integer math (22.9%) and physics (18.7%), pointing to strong ALU performance and simulation workloads. Data compression and encryption show moderate advantages of 14.4% and 15.9%, respectively, suggesting the Ultra 9 285 handles data-heavy tasks with noticeable but not overwhelming superiority.

For multi-threaded production workloads, the Ultra 9 285 leads by 33.4% in Cinebench R23 multi-core and 16.4% in Cinebench R20 multi-core. The newer Cinebench versions show larger gaps, which indicates the Ultra 9 285 benefits more from its additional cores and larger L3 cache under sustained multi-threaded rendering. The Ultra 7 255HX, as a mobile part with a 55 watt TDP, cannot sustain the same performance envelope as the 65 watt desktop part.

FAQ

Q: Which processor has a higher average benchmark score?

A: The Intel Core Ultra 9 285 averages 75488 across all benchmark results, while the Intel Core Ultra 7 255HX averages 62738.

Q: How much faster is the Ultra 9 285 in single-core performance?

A: The Ultra 9 285 leads by 68.7% in Cinebench R23 single-core, 53% in Cinebench R15 single-core, 16.4% in Cinebench R20 single-core, and 6.5% in PassMark single-thread.

Q: Do both processors use the same manufacturing process?

A: Yes, both use TSMC's 3 nm process node, and both have 17,800 million transistors on a 243 mm² die.

Q: What is the core and thread count difference?

A: The Ultra 9 285 provides 24 cores and 24 threads, while the Ultra 7 255HX provides 20 cores and 20 threads. Neither processor supports hyperthreading.

Q: Is there any benchmark where the Ultra 7 255HX wins?

A: No, the database records zero wins for the Ultra 7 255HX across all 17 head-to-head comparisons. The closest result is Cinebench R15 multi-core, where it trails by only 0.3%.

Q: Which processor supports ECC memory?

A: The Ultra 9 285 supports ECC memory, while the Ultra 7 255HX does not. Both support DDR5 with dual-channel memory and 102.4 GB/s bandwidth.

The Verdict

The data indicates a decisive performance hierarchy. The Intel Core Ultra 9 285 is the faster processor in every measured workload, with its largest advantages appearing in single-threaded and modern multi-threaded benchmarks. The 68.7% lead in Cinebench R23 single-core and the 33.4% lead in Cinebench R23 multi-core establish it as the stronger choice for both lightly threaded and heavily threaded applications. Its 24 cores, 36 MB of shared L3 cache, higher boost clock of 5.60 GHz, and 65 watt TDP all contribute to this performance profile.

The Intel Core Ultra 7 255HX is a mobile part designed for a different environment. Its 55 watt TDP, 20 cores, 30 MB of shared L3, and 5.20 GHz boost clock make it competitive in older multi-core workloads, as shown by the 0.3% gap in Cinebench R15 multi-core. The 6.5% PassMark single-thread deficit indicates the mobile part is not far behind in general single-threaded throughput. However, in modern rendering workloads and math-intensive PassMark tests, the desktop part pulls ahead significantly.

Buyers should choose based on platform needs. The Ultra 7 255HX uses Intel BGA 2114 and targets mobile systems, with an unlocked multiplier for overclocking. The Ultra 9 285 uses Intel Socket 1851 for desktop builds, has a locked multiplier, supports ECC memory, and carries a launch MSRP of $579. For users who need maximum performance across all benchmark categories, the Ultra 9 285 is the clear choice. For mobile applications where the 55 watt TDP and BGA socket are required, the Ultra 7 255HX is the only option in this comparison. The database shows no workload where the Ultra 7 255HX overtakes the Ultra 9 285.

Specification Differences

| Specification | Intel Core Ultra 7 255HX | Intel Core Ultra 9 285 |

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

| Cores | 20 | 24 |

| Threads | 20 | 24 |

| Base clock | 2.40 GHz | 2.50 GHz |

| Boost clock | 5.20 GHz | 5.60 GHz |

| TDP | 55 watts | 65 watts |

| Socket | Intel BGA 2114 | Intel Socket 1851 |

| Codename | Arrow Lake-HX | Arrow Lake-S |

| Generation | Ultra 7 (Arrow Lake-HX) | Ultra 9 (Arrow Lake) |

| L3 cache | 30 MB (shared) | 36 MB (shared) |

| ECC memory | No | Yes |

| Market segment | Mobile | Desktop |

| Release date | 2025-01-12 | 2024-12-31 |

| Launch MSRP | None recorded | $579 |

| Multiplier unlocked | Yes | No |

| Part number | SRVFG | SRQD4 |