Intel Core i5-3450S vs Intel Core i7-5557U Comparison

Head-to-Head Benchmarks

The benchmark comparison between the Intel Core i7-5557U and Intel Core i5-3450S reveals a clear split along workload type. The i5-3450S dominates in Cinebench tests across all versions, while the i7-5557U takes decisive wins in Geekbench workloads.

In Cinebench R15 multicore, the i5-3450S scores 377 against the i7-5557U's 270, a 28.4% advantage. That same 28.4% delta repeats in Cinebench R20 multicore, where the i5-3450S posts 1573 versus 1126. Cinebench R23 multicore follows the identical pattern: 3747 for the i5-3450S versus 2682 for the i7-5557U, again a 28.4% gap. The consistency of this margin across three generations of Cinebench multicore tests indicates a stable performance differential, not a workload-specific anomaly.

Single-core Cinebench results tell a similar story, though the delta is slightly larger. In Cinebench R20 single-core, the i5-3450S scores 222 versus 158 for the i7-5557U, a 28.8% lead. Cinebench R23 single-core shows 529 versus 378, a 28.5% gap. The i5-3450S wins all five Cinebench comparisons, and the margins are tightly clustered between 28.4% and 28.8%, suggesting a consistent architectural advantage in rendering workloads.

The Geekbench results flip the narrative entirely. In Geekbench multicore, the i7-5557U scores 2099 against 1712 for the i5-3450S, a 22.6% win for the mobile chip. The single-core Geekbench test is even more lopsided: the i7-5557U posts 1060 versus 581, an 82.4% advantage. That 82.4% delta is the largest margin in the entire head-to-head set, and it highlights how differently these two processors respond to Geekbench's workload mix compared to Cinebench's rendering-focused tests.

Overall, the i5-3450S wins 5 of the 7 head-to-head benchmarks, while the i7-5557U takes 2. However, the average benchmark scores tell a much closer story: the i7-5557U averages 1110, while the i5-3450S averages 1099. Both processors sit at the 31st percentile among all CPUs in the database, and their nearest rivals reinforce this parity. The i7-5557U is matched exactly (0% delta) by the Intel Xeon E5630 at 1110, while the i5-3450S is matched exactly by the Intel Pentium 6805 at 1099.

Architecture Differences

The two processors come from different Intel eras and design philosophies. The i7-5557U is a Broadwell-U part built on a 14 nm process, while the i5-3450S is an Ivy Bridge desktop chip on a 22 nm node. This process advantage translates into a smaller die for the i7-5557U at 133 mm², despite packing 1,900 million transistors. The i5-3450S uses a larger 160 mm² die with 1,400 million transistors, meaning the Broadwell part achieves higher transistor density on a smaller physical footprint.

Core counts differ significantly. The i7-5557U has 2 physical cores with 4 threads via Hyper-Threading, while the i5-3450S has 4 physical cores with 4 threads and no Hyper-Threading. This explains the Cinebench results: the i5-3450S benefits from two additional physical cores in heavily threaded rendering workloads, while the i7-5557U relies on its two cores plus additional thread scheduling.

Cache configurations also diverge. Both share 64 KB of L1 cache per core and 256 KB of L2 cache per core, but the L3 cache differs: the i7-5557U has 4 MB shared, while the i5-3450S has 6 MB shared. That extra 2 MB of L3 cache gives the desktop part more room for shared data across its four cores.

Clock speeds are close but not identical. The i7-5557U runs at 3.10 GHz base and 3.40 GHz boost, while the i5-3450S runs at 2.80 GHz base and 3.50 GHz boost. The i5-3450S has a higher boost clock by 0.10 GHz, but the i7-5557U has a higher base clock by 0.30 GHz. Neither chip is multiplier-unlocked.

Thermal and platform targets differ sharply. The i7-5557U has a 28 W TDP and uses the Intel BGA 1168 socket, a mobile package. The i5-3450S has a 65 W TDP and uses the Intel Socket 1155, a desktop platform. This is a 37 W TDP gap, reflecting the i7-5557U's design for thin-and-light laptops versus the i5-3450S's desktop cooling envelope.

Memory support is DDR3 for both, with dual-channel buses. The i7-5557U lists a memory bandwidth of 29.9 GB/s, while the i5-3450S has no recorded bandwidth figure. PCIe connectivity also differs: the i7-5557U offers Gen 2 with 12 lanes (CPU only), while the i5-3450S offers Gen 3 with 16 lanes (CPU only). That is a full generation and 4 additional lanes for the desktop part.

Integrated graphics separate the two as well. The i7-5557U carries Intel Iris 6100, a higher-tier mobile GPU, while the i5-3450S carries Intel HD 2500, a basic desktop solution. Neither supports ECC memory.

Where Each One Wins

The i5-3450S is the clear winner for multi-threaded rendering and compute workloads. Its 28.4% lead across Cinebench R15, R20, and R23 multicore tests shows that the two extra physical cores provide a substantial and consistent advantage in tasks that scale with core count. The single-core Cinebench results, with deltas around 28.5% to 28.8%, also favor the i5-3450S, which is notable because single-core performance is often expected to favor newer architectures. In this comparison, the older Ivy Bridge part simply has a higher boost clock and more mature frequency behavior under sustained load.

The i7-5557U wins in Geekbench, and the margins are substantial. The 22.6% multicore win and the massive 82.4% single-core win suggest that Geekbench's workload mix, which includes memory latency, encryption, and compression tasks, plays to the Broadwell architecture's strengths. The i7-5557U's 14 nm process and improved memory controller likely contribute to these results, even with fewer physical cores.

For use-case planning, the i5-3450S suits desktop systems where rendering, video encoding, or other threaded production tasks dominate and where the 65 W TDP is acceptable. The i7-5557U suits mobile platforms where power efficiency matters, but the data shows it trades away significant Cinebench performance. The 31st percentile ranking for both chips means neither is a high-end part today, but the i5-3450S offers more predictable multi-core throughput, while the i7-5557U offers better Geekbench responsiveness.

FAQ

Q: Which processor has better multi-core rendering performance?

A: The Intel Core i5-3450S wins all three Cinebench multicore tests. It leads by 28.4% in R15 (377 versus 270), R20 (1573 versus 1126), and R23 (3747 versus 2682).

Q: How large is the single-core performance gap?

A: The i5-3450S leads in Cinebench single-core tests by 28.8% in R20 (222 versus 158) and 28.5% in R23 (529 versus 378). However, the i7-5557U leads in Geekbench single-core by 82.4% (1060 versus 581).

Q: Which chip wins more benchmarks overall?

A: The i5-3450S wins 5 of the 7 head-to-head benchmarks. The i7-5557U wins 2. Despite this, their average benchmark scores are nearly identical: 1110 for the i7-5557U and 1099 for the i5-3450S.

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

A: The i7-5557U has 2 cores and 4 threads. The i5-3450S has 4 cores and 4 threads. Neither chip has an unlocked multiplier.

Q: How do their process nodes and transistor counts compare?

A: The i7-5557U uses a 14 nm process with 1,900 million transistors on a 133 mm² die. The i5-3450S uses a 22 nm process with 1,400 million transistors on a 160 mm² die.

Q: What are the TDP and socket differences?

A: The i7-5557U has a 28 W TDP and uses Intel BGA 1168. The i5-3450S has a 65 W TDP and uses Intel Socket 1155. The i7-5557U is a mobile part, while the i5-3450S is a desktop part.

Specification Differences

| Specification | Intel Core i7-5557U | Intel Core i5-3450S |

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

| Cores | 2 | 4 |

| Threads | 4 | 4 |

| Base Clock | 3.10 GHz | 2.80 GHz |

| Boost Clock | 3.40 GHz | 3.50 GHz |

| TDP | 28 W | 65 W |

| Socket | Intel BGA 1168 | Intel Socket 1155 |

| Architecture | Broadwell | Ivy Bridge |

| Codename | Broadwell-U | Ivy Bridge |

| Process Node | 14 nm | 22 nm |

| Transistors | 1,900 million | 1,400 million |

| Die Size | 133 mm² | 160 mm² |

| L3 Cache | 4 MB (shared) | 6 MB (shared) |

| Memory Bandwidth | 29.9 GB/s | Not recorded |

| PCIe | Gen 2, 12 Lanes (CPU only) | Gen 3, 16 Lanes (CPU only) |

| Integrated Graphics | Intel Iris 6100 | Intel HD 2500 |

| Market Segment | Mobile | Desktop |

| Release Date | 2015-02-28 | 2012-04-28 |

| Launch MSRP | $426 | Not recorded |

| Part Number | SR26E | SR0P2 |

The i7-5557U also carries a 2-core, 4-thread design with 64 KB L1 and 256 KB L2 per core, matching the per-core cache layout of the i5-3450S. Both support DDR3 memory in dual-channel mode, and neither supports ECC memory. The i7-5557U is listed as end-of-life, while the i5-3450S has no production status recorded. Both processors sit at the 31st percentile among all CPUs in the database.