Intel Core i5-5300U vs Intel Core i7-940 Comparison

FAQ

Q: Which processor has more cores and threads?

A: The Intel Core i7-940 has 4 cores and 8 threads, while the Intel Core i5-5300U has 2 cores and 4 threads. The i7-940 doubles both core and thread counts.

Q: How do their average benchmark scores compare?

A: The Intel Core i7-940 has an average benchmark score of 903, while the Intel Core i5-5300U scores 895. The difference is 8 points, placing them both at the 24th percentile among all CPUs.

Q: Which chip has a smaller manufacturing process?

A: The Intel Core i5-5300U uses a 14 nm process node, while the Intel Core i7-940 uses a 45 nm node. The i5-5300U's process is substantially newer and smaller.

Q: What is the TDP difference between the two?

A: The Intel Core i7-940 has a TDP of 130 watts, while the Intel Core i5-5300U has a TDP of 15 watts. The i5-5300U consumes dramatically less power.

Q: Which processor includes integrated graphics?

A: The Intel Core i5-5300U includes Intel HD 5500 integrated graphics. The Intel Core i7-940 has no integrated graphics listed.

Q: What memory bus configurations do they support?

A: The Intel Core i7-940 supports triple-channel DDR3 memory, while the Intel Core i5-5300U supports dual-channel DDR3 and has a listed memory bandwidth of 25.6 GB/s.

Architecture Differences

The two processors represent fundamentally different design eras and objectives. The Intel Core i7-940 is a desktop part built on the Nehalem architecture with the Bloomfield codename, manufactured on a 45 nm process node. It contains 731 million transistors on a 263 mm² die. The Intel Core i5-5300U is a mobile part built on the Broadwell architecture with the Broadwell-U codename, manufactured on a 14 nm process node. It packs 1,300 million transistors into an 82 mm² die — a much denser integration.

The cache hierarchies differ sharply. The i7-940 carries 64 KB of L1 per core and 256 KB of L2 per core, plus a shared 8 MB L3 cache. The i5-5300U has the same per-core L1 and L2 sizes, but its shared L3 is only 3 MB. The i7-940's larger L3 is a direct consequence of its higher core count and desktop-oriented design, while the i5-5300U's smaller cache reflects its mobile efficiency focus.

Memory support also diverges. The i7-940 uses triple-channel DDR3, giving it a wider memory bus, while the i5-5300U uses dual-channel DDR3 with a measured bandwidth of 25.6 GB/s. Both support DDR3 memory, but neither supports ECC. PCIe connectivity is Gen 2 on both, though the i5-5300U specifies 12 lanes (CPU only), while the i7-940 does not list a lane count.

The i5-5300U includes Intel HD 5500 integrated graphics, which the i7-940 lacks entirely. This is a critical architectural difference: the mobile chip can drive displays without a discrete GPU, whereas the desktop chip requires a separate graphics card. The i5-5300U is also built for a BGA 1168 socket, making it soldered to the motherboard, while the i7-940 uses the socketed Intel Socket 1366, allowing upgrades.

The production status of both is end-of-life. The i7-940 was released in November 2008, while the i5-5300U came in February 2015 — a gap of more than six years. Neither has an unlocked multiplier. The i7-940's base clock is 2.93 GHz with a boost of 3.20 GHz; the i5-5300U runs at 2.30 GHz base and 2.90 GHz boost. The i7-940's part number is SLBCK, and the i5-5300U's is SR23X.

The Verdict

The data presents a clear but nuanced picture. The Intel Core i7-940 wins every single head-to-head benchmark in the comparison, taking all 5 wins with a consistent delta of approximately 14.8% across Cinebench R15, R20, and R23 multi-core and single-core tests. Its advantage is uniform: 264 versus 230 in R15 multi-core, 1102 versus 960 in R20 multi-core, 155 versus 135 in R20 single-core, 2626 versus 2287 in R23 multi-core, and 370 versus 322 in R23 single-core.

However, the i7-940's dominance comes at a massive power cost. Its 130-watt TDP is nearly nine times higher than the i5-5300U's 15-watt TDP. The i7-940 also lacks integrated graphics, requires a socketed desktop platform, and uses an older 45 nm process. For a desktop user with a discrete GPU and adequate cooling, the i7-940 is the performance choice. For a mobile or low-power system, the i5-5300U is the only viable option — its 15-watt TDP and integrated graphics make it suitable for laptops where the i7-940 could never operate.

The average benchmark scores are nearly identical (903 versus 895), and both sit at the 24th percentile of all CPUs. The i7-940's nearest rival is the Intel Core i5-5350U with an identical average score of 903 and a delta of 0%. The i5-5300U's nearest rival is the Intel Pentium G4600T, also matching at 895 with a 0% delta. This suggests that in real-world mixed workloads, the two chips perform at a similar level despite the i7-940's benchmark wins — the i5-5300U's newer architecture compensates for its lower core count in some scenarios.

Specification Differences

| Field | Intel Core i7-940 | Intel Core i5-5300U |

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

| Cores | 4 | 2 |

| Threads | 8 | 4 |

| Base Clock | 2.93 GHz | 2.30 GHz |

| Boost Clock | 3.20 GHz | 2.90 GHz |

| TDP | 130 W | 15 W |

| Socket | Intel Socket 1366 | Intel BGA 1168 |

| Architecture | Nehalem | Broadwell |

| Codename | Bloomfield | Broadwell-U |

| Process Node | 45 nm | 14 nm |

| Transistors | 731 million | 1,300 million |

| Die Size | 263 mm² | 82 mm² |

| L3 Cache | 8 MB (shared) | 3 MB (shared) |

| Memory Bus | Triple-channel | Dual-channel |

| Memory Bandwidth | Not listed | 25.6 GB/s |

| Integrated Graphics | None | Intel HD 5500 |

| Market Segment | Desktop | Mobile |

| Release Date | November 2008 | February 2015 |

| Part Number | SLBCK | SR23X |

The two chips share identical L1 and L2 cache sizes per core (64 KB and 256 KB respectively), both use DDR3 memory, both lack ECC support, both use PCIe Gen 2, and both are end-of-life with locked multipliers.

Head-to-Head Benchmarks

The Intel Core i7-940 wins every benchmark in the head-to-head comparison, and the margin is remarkably consistent. In Cinebench R15 multi-core, the i7-940 scores 264 against the i5-5300U's 230, a delta of 14.8%. The same 14.8% delta appears in Cinebench R20 multi-core, where scores are 1102 versus 960, and in Cinebench R20 single-core, where the i7-940 posts 155 against 135.

The pattern continues in Cinebench R23. Multi-core results show the i7-940 at 2626 versus 2287, again a 14.8% gap. Single-core R23 shows 370 against 322, with a slightly larger 14.9% delta. This uniformity across all five tests is notable — it suggests the i7-940's advantage is structural rather than workload-specific. The 14.8% edge persists whether the test is multi-core or single-core, which is unusual. Typically, a higher-core-count chip would show a larger advantage in multi-threaded tests, but here the single-core tests show the same margin.

The i5-5300U does have additional benchmarks in its individual data — Geekbench multi-core at 1540 and single-core at 791 — but these are not part of the head-to-head comparison, so they cannot be directly compared against the i7-940. The i7-940's individual benchmark list includes Cinebench R15, R20, and R23 variants only.

The average benchmark scores tell a different story than the head-to-head results. The i7-940 averages 903 points, while the i5-5300U averages 895. This narrow 8-point gap (roughly 0.9%) contrasts sharply with the 14.8% head-to-head margins. The explanation lies in the benchmark mix: the i5-5300U's Geekbench scores (1540 multi-core, 791 single-core) are likely weighted in its average, and its nearest rival comparison shows it matching the Intel Core i3-6100 at 888 with a 0.7% delta, while the i7-940 matches the Intel Core i5-5350U at 903 with a 0% delta.

Where Each One Wins

Multi-core workloads: The Intel Core i7-940 wins decisively. Its 4 cores and 8 threads outperform the i5-5300U's 2 cores and 4 threads by 14.8% in every Cinebench multi-core test. For rendering, video encoding, or any parallel task, the i7-940 is the better choice.

Single-core workloads: Surprisingly, the i7-940 also wins single-core tests by the same 14.8% margin. Despite its older architecture and lower boost clock efficiency, the i7-940's 3.20 GHz boost clock outperforms the i5-5300U's 2.90 GHz boost in Cinebench R20 and R23 single-core tests. The i5-5300U's newer Broadwell architecture does not compensate for its lower clock speeds.

Power-constrained environments: The Intel Core i5-5300U wins categorically. Its 15-watt TDP versus 130 watts means it can operate in laptops, ultrabooks, and fanless designs where the i7-940 is impossible. The i5-5300U also includes Intel HD 5500 graphics, enabling display output without a discrete GPU.

Desktop builds with discrete GPUs: The i7-940 is the winner. Its socketed design (Intel Socket 1366) allows for upgrades, and its lack of integrated graphics is irrelevant when a dedicated GPU is present. The triple-channel memory bus provides additional bandwidth for memory-intensive applications.

Compact or integrated systems: The i5-5300U wins due to its BGA 1168 socket and integrated graphics, which allow for smaller motherboards and simpler system assembly. Its 82 mm² die size and 14 nm process also make it suitable for thermally constrained chassis.

Legacy platform considerations: The i7-940, released in November 2008, offers no launch MSRP data, while the i5-5300U has a launch MSRP of $315. This difference reflects their market positions: the i7-940 was a high-end desktop part, while the i5-5300U was a mid-range mobile part. Both are now end-of-life, so availability is limited to used markets.