Intel Core 7 251E vs Intel Core Ultra 7 155HL Comparison

Where Each One Wins

The data splits these two Intel desktop processors into clearly different roles. The Intel Core 7 251E is built around raw thread count and clock speed, making it the stronger choice for heavily parallel workloads and high-frequency single-thread tasks. The Intel Core Ultra 7 155HL counters with a more power-efficient design, a newer hybrid architecture, and a substantially more capable integrated graphics solution, positioning it for compact systems where balanced performance and lower power draw matter more.

The Core 7 251E uses 24 cores and 32 threads against the Core Ultra 7 155HL's 16 cores and 22 threads. That eight-thread advantage, combined with a 5.60 GHz boost clock versus 4.80 GHz, gives the 251E clear authority in multi-threaded rendering, compilation, and simulation workloads. The 155HL cannot match that core count, but its 45 W TDP against the 251E's 65 W TDP shows a deliberate trade: less peak throughput for lower sustained power consumption, which matters in thermally constrained chassis.

Integrated graphics is where the 155HL wins decisively. It ships with Arc Xe-LPG 128EU, while the 251E carries UHD Graphics 770. The Arc solution represents a generational leap in iGPU capability, suitable for light gaming, hardware-accelerated video encoding, and general media work without a discrete card. The 251E's UHD 770 remains functional for basic display output but offers far less compute headroom.

Socket compatibility also splits them. The 251E fits Intel Socket 1700, a widely adopted platform with DDR4 and DDR5 memory support. The 155HL uses Intel Socket 1851 and depends on the motherboard for DDR5 support, which narrows upgrade paths but aligns with newer platform features. The 251E also adds ECC memory support, a feature absent on the 155HL, making it the safer choice for error-sensitive workstation tasks.

Architecture Differences

The two chips come from different Intel design lineages. The Core 7 251E uses the Bartlett Lake codename, built on a 10 nm process node with a 257 mm² die size. The Core Ultra 7 155HL uses Meteor Lake, specifically the Meteor Lake-PS variant, on a 7 nm process node with no die size recorded in the database. The process difference is notable: the 155HL uses a more advanced node, which partially explains its lower power envelope despite newer architectural features.

Cache layouts differ meaningfully. The 251E provides 80 KB of L1 per core, 2 MB of L2 per core, and 36 MB of shared L3. The 155HL provides 112 KB of L1 per core, 2 MB of L2 per core, but only 24 MB of shared L3. The 251E holds a 12 MB L3 advantage, which helps when large working sets are repeatedly accessed, a common pattern in database queries and scientific computing. The 155HL's larger per-core L1 suggests a different design philosophy, favoring lower latency for individual threads rather than a massive shared cache.

PCIe connectivity also diverges. The 251E offers PCIe Gen 5 with 16 CPU lanes, while the 155HL offers PCIe Gen 4 with only 8 CPU lanes. That translates into double the lane count and a newer generation on the 251E, enabling faster NVMe storage and discrete GPU connections. The 155HL's reduced PCIe bandwidth reflects its focus on integrated, power-conscious designs rather than expansion-heavy builds.

Memory support shows another split. The 251E supports both DDR4 and DDR5, giving builders flexibility to reuse older RAM or adopt newer modules. The 155HL supports only DDR5, and the database notes that support depends on the motherboard, meaning the platform dictates the final memory configuration. Both use dual-channel memory buses with identical 89.6 GB/s bandwidth, so peak theoretical memory throughput matches, but the 251E offers more practical options.

ECC memory is exclusive to the 251E. This feature allows error detection and correction in memory operations, which is critical for long-running compute jobs, file servers, and any workload where a single bit flip causes corruption. The 155HL lacks ECC support entirely, limiting its suitability for those applications.

Head-to-Head Benchmarks

The database contains no recorded head-to-head benchmark scores for these two processors, so direct numerical comparisons must rely on the specification data available. The most decisive numbers come from core count, clock speed, and cache size.

The 251E holds a 33% core advantage (24 versus 16) and a 45% thread advantage (32 versus 22). This translates directly into multi-threaded performance potential. In rendering workloads where scaling is near-linear, the 251E could deliver roughly one-third more throughput, assuming similar per-core efficiency. The 155HL's newer 7 nm process may improve per-core efficiency, but it cannot overcome the raw thread deficit.

Single-thread performance favors the 251E through clock speed alone. Its 5.60 GHz boost is 17% higher than the 155HL's 4.80 GHz. For lightly threaded applications like older games, spreadsheet macros, or single-threaded scripting, the 251E should complete tasks faster. The 155HL's larger L1 cache (112 KB versus 80 KB per core) may mitigate some of that clock disadvantage in latency-sensitive loops, but the frequency gap remains substantial.

The 155HL answers with its integrated graphics. The Arc Xe-LPG 128EU is a discrete-class iGPU, while the UHD 770 is a basic graphics processor. For media transcoding, the Arc's dedicated hardware encoders outperform Intel's older UHD solution. For light gaming at lower resolutions, the Arc can deliver playable frame rates where the UHD 770 would struggle. This is not a benchmark score, but the architectural difference is stark.

Power efficiency is another measurable differentiator. The 155HL operates at 45 W TDP, which is 31% lower than the 251E's 65 W TDP. In sustained all-core workloads, the 155HL will generate less heat and require less cooling, enabling smaller system designs. The 251E needs a more robust cooling solution and a power supply with greater headroom.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Core 7 251E has 24 cores and 32 threads. The Intel Core Ultra 7 155HL has 16 cores and 22 threads. The 251E holds a clear advantage in parallel workload capacity.

Q: Do both processors support the same memory types?

A: No. The Core 7 251E supports both DDR4 and DDR5. The Core Ultra 7 155HL supports only DDR5, and the database notes that support depends on the motherboard. Both use dual-channel memory with 89.6 GB/s bandwidth.

Q: Which processor includes ECC memory support?

A: The Core 7 251E supports ECC memory. The Core Ultra 7 155HL does not. ECC support is a key differentiator for workstation and server-style applications.

Q: How do the integrated graphics compare?

A: The Core Ultra 7 155HL uses Arc Xe-LPG 128EU, a more powerful integrated GPU. The Core 7 251E uses UHD Graphics 770. The Arc solution is significantly more capable for graphics and media workloads.

Q: What are the socket requirements for each processor?

A: The Core 7 251E uses Intel Socket 1700. The Core Ultra 7 155HL uses Intel Socket 1851. They are not interchangeable, and each requires a matching motherboard.

Q: Which processor has the higher boost clock?

A: The Core 7 251E boosts to 5.60 GHz. The Core Ultra 7 155HL boosts to 4.80 GHz. The 251E has a 17% higher boost frequency.

The Verdict

The Intel Core 7 251E is the choice for compute-heavy desktop builds that prioritize raw throughput and platform flexibility. Its 24 cores, 32 threads, 36 MB L3 cache, PCIe Gen 5 support, and ECC memory capability make it suitable for multi-threaded rendering, software compilation, data analysis, and any workload that scales with thread count. The higher 65 W TDP is a fair trade for that performance, and the dual DDR4/DDR5 support eases system assembly.

The Intel Core Ultra 7 155HL targets a different segment. Its 45 W TDP, Arc Xe-LPG 128EU graphics, and 7 nm process node point toward compact desktops, media centers, and light creative systems where power efficiency and integrated graphics matter more than peak core counts. The 16 cores and 22 threads remain adequate for mainstream productivity, and the 4.80 GHz boost covers single-thread needs adequately.

For users who need maximum multi-threaded performance and ECC reliability, the 251E is the clear pick from the data. For users who want a lower-power chip with far better integrated graphics and a newer architecture, the 155HL is the better fit. The 12 MB L3 cache advantage and double PCIe lane count on the 251E reinforce its workstation orientation, while the 155HL's superior iGPU and lower power draw define its compact-system role. Neither is universally better; the data supports each for distinct use cases.

Specification Differences

| Specification | Intel Core 7 251E | Intel Core Ultra 7 155HL |

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

| Cores | 24 | 16 |

| Threads | 32 | 22 |

| Base Clock | 2.10 GHz | 1.40 GHz |

| Boost Clock | 5.60 GHz | 4.80 GHz |

| TDP | 65 W | 45 W |

| Socket | Intel Socket 1700 | Intel Socket 1851 |

| Codename | Bartlett Lake | Meteor Lake-PS |

| Process Node | 10 nm | 7 nm |

| Die Size | 257 mm² | Not recorded |

| L1 Cache | 80 KB (per core) | 112 KB (per core) |

| L2 Cache | 2 MB (per core) | 2 MB (per core) |

| L3 Cache | 36 MB (shared) | 24 MB (shared) |

| Memory Support | DDR4, DDR5 | DDR5 (depends on motherboard) |

| Memory Bandwidth | 89.6 GB/s | 89.6 GB/s |

| ECC Memory | Yes | No |

| PCIe | Gen 5, 16 Lanes (CPU only) | Gen 4, 8 Lanes (CPU only) |

| Integrated Graphics | UHD Graphics 770 | Arc Xe-LPG 128EU |

| Launch MSRP | $384 | $438 |

| Release Date | 2025-01-12 | 2024-04-07 |

| Multiplier Unlocked | No | No |

| Production Status | Active | Active |