Intel Core i5-2405S vs Intel Core i5-5257U Comparison

Head-to-Head Benchmarks

The benchmark data presents a fascinating split, with the older desktop part winning the majority of tests while the newer mobile chip takes the Geekbench crown decisively. Across the Cinebench suite, the Intel Core i5-2405S consistently leads by a margin of roughly 20% in every single test. In Cinebench R15 multicore, the i5-2405S scores 291 against 242 for the i5-5257U, a 20.2% advantage. The R20 multicore test shows a similar story: 1213 versus 1010, a 20.1% gap. Even in single-core Cinebench tests, where mobile parts often excel, the i5-2405S wins by 20.4% in both R20 (171 vs 142) and R23 (408 vs 339). The R23 multicore result continues the pattern with 2890 against 2406, another 20.1% lead.

The Geekbench results, however, flip the script entirely. The i5-5257U posts a multicore score of 1773, which is 19.6% higher than the i5-2405S's 1425. The single-core gap is even more striking: 922 versus 541, a massive 41.3% differential favoring the Broadwell chip. This is the largest single margin in the entire comparison, and it suggests that the newer architecture has a substantial advantage in workloads that depend heavily on single-threaded performance and modern instruction efficiency, even though the older Sandy Bridge chip wins the Cinebench suite outright.

What makes this interesting is the contradiction between benchmark families. The Cinebench tests are consistent in their verdict, while Geekbench is equally consistent in the opposite direction. The data implies that the two processors are tuned for different kinds of compute. The i5-2405S, with four physical cores, handles the heavily threaded Cinebench render loops better. The i5-5257U, despite having only two cores, appears to extract more performance per clock in Geekbench's more varied and latency-sensitive workload. The result is a 5-to-2 win split in favor of the desktop chip, but the two wins for the mobile part are not trivial; they are the largest deltas recorded in either direction.

FAQ

Q: Which processor is faster in Cinebench R23 multicore?

A: The Intel Core i5-2405S is faster, scoring 2890 compared to 2406 for the i5-5257U, a 20.1% advantage.

Q: How much faster is the i5-5257U in Geekbench single-core?

A: The i5-5257U scores 922 versus 541 for the i5-2405S, which is a 41.3% higher result.

Q: What is the average benchmark score for each processor?

A: The i5-2405S has an average benchmark score of 991, while the i5-5257U averages 976. The difference is small, only about 1.5% in favor of the desktop chip.

Q: Does the i5-5257U have a higher TDP?

A: No, the i5-5257U has a TDP of 28 watts, which is much lower than the 65-watt TDP of the i5-2405S.

Q: Which processor supports PCIe Gen 3?

A: The Intel Core i5-2405S supports PCIe Gen 3 with 16 lanes (CPU only), while the i5-5257U supports PCIe Gen 2 with 12 lanes.

Q: What is the difference in process node?

A: The i5-2405S is built on a 32 nm process, while the i5-5257U uses a 14 nm process. The newer node is smaller, which typically allows for higher transistor density and lower power consumption.

Where Each One Wins

The i5-2405S wins in every Cinebench workload, which are rendering and 3D modeling tasks that scale with core count and sustained throughput. Its four physical cores provide a clear edge in multi-threaded render loops, as evidenced by the 20.1% to 20.2% leads in R15, R20, and R23 multicore tests. Even in single-core Cinebench tests, the older chip maintains a 20.4% lead, which is surprising given that the mobile part has a higher base clock (2.70 GHz versus 2.50 GHz). This suggests that the Cinebench benchmark family responds well to the i5-2405S's higher boost clock of 3.30 GHz, which is 0.20 GHz above the i5-5257U's 3.10 GHz boost. For users running CPU-bound render jobs or batch processing, the i5-2405S is the clear winner from the recorded data.

The i5-5257U wins in Geekbench, both single-core and multicore. The single-core victory is enormous at 41.3%, and the multicore win is 19.6% despite having half the physical cores. Geekbench is known for testing a broader range of real-world scenarios, including encryption, compression, and memory-bound tasks. The Broadwell architecture's newer design, with a 14 nm process and integrated Iris 6100 graphics, appears to deliver superior per-clock efficiency and memory handling. The i5-5257U also has a specified memory bandwidth of 29.9 GB/s, whereas the i5-2405S does not have a recorded bandwidth figure in the database. For workloads that are latency-sensitive or that rely on modern instruction sets, the i5-5257U is the superior part.

The use-case split is clear: rendering and traditional multi-threaded workloads favor the i5-2405S, while general-purpose computing, single-threaded tasks, and memory-heavy applications favor the i5-5257U. The i5-5257U's 28-watt TDP also makes it a candidate for power-constrained environments, while the i5-2405S's 65-watt TDP implies a need for more substantial cooling and power delivery.

Specification Differences

The two processors differ in nearly every fundamental specification category. The i5-2405S has 4 cores and 4 threads, while the i5-5257U has 2 cores and 4 threads. Base clocks are close: 2.50 GHz for the i5-2405S versus 2.70 GHz for the i5-5257U. Boost clocks are also similar, with the i5-2405S reaching 3.30 GHz and the i5-5257U reaching 3.10 GHz. The TDP is a major differentiator: 65 watts for the desktop part versus 28 watts for the mobile part.

The sockets are entirely different: the i5-2405S uses Intel Socket 1155, while the i5-5257U uses Intel BGA 1168, which is a soldered mobile package. Memory support is DDR3 for both, and both use dual-channel memory buses. The i5-5257U has a recorded memory bandwidth of 29.9 GB/s, while the i5-2405S does not have a bandwidth figure in the database. PCIe support differs: the i5-2405S offers Gen 3 with 16 lanes (CPU only), whereas the i5-5257U offers Gen 2 with 12 lanes. Integrated graphics are different as well: Intel HD 3000 on the i5-2405S versus Intel Iris 6100 on the i5-5257U.

The market segments are opposite: the i5-2405S is a desktop part, while the i5-5257U is a mobile part. Release dates are separated by roughly four years, with the i5-2405S launching in 2011 and the i5-5257U in 2015. Neither processor has an unlocked multiplier. The i5-5257U has a launch MSRP of $315. The part numbers are SR0BB for the i5-2405S and SR26K for the i5-5257U.

Architecture Differences

The architectural gap is substantial. The i5-2405S is based on Sandy Bridge, built on a 32 nm process with 1,160 million transistors on a 216 mm² die. The i5-5257U is based on Broadwell, built on a 14 nm process with 1,900 million transistors on a 133 mm² die. The newer process packs far more transistors into a smaller area, which explains the i5-5257U's superior efficiency and per-clock performance in certain workloads.

Cache configurations differ notably. The i5-2405S has 64 KB of L1 cache per core and 256 KB of L2 cache per core, just like the i5-5257U. However, the L3 cache is 6 MB shared on the i5-2405S versus only 3 MB shared on the i5-5257U. This means the desktop part has double the last-level cache, which likely contributes to its strong Cinebench showing.

The integrated graphics are from different generations: Intel HD 3000 on the Sandy Bridge part versus Intel Iris 6100 on the Broadwell part. The Iris 6100 is a more capable integrated GPU, but the database does not provide graphics benchmarks for this comparison. The i5-5257U's 14 nm process and 1,900 million transistors suggest a much more complex and modern design, which aligns with its Geekbench dominance.

The memory bandwidth specification for the i5-5257U (29.9 GB/s) is present, while the i5-2405S lacks that figure, indicating that the mobile part has a formally documented memory throughput advantage. The PCIe generation difference (Gen 3 vs Gen 2) also reflects the architectural evolution, with the newer part using a more power-efficient but lower-bandwidth PCIe implementation.

The Verdict

The data points to a clear but nuanced conclusion. The Intel Core i5-2405S is the better choice for users who prioritize multi-threaded rendering and compute throughput, as it wins all Cinebench tests by a consistent 20% margin. Its 4-core/4-thread configuration and larger 6 MB L3 cache give it a decisive edge in workloads that exploit parallelism. The i5-2405S also edges out the i5-5257U in average benchmark score, 991 versus 976, placing it in the 27th percentile versus the 26th percentile for the mobile chip. Its nearest rivals include the Intel Core i7-960 and the AMD Phenom II X6 1065T, with a delta of -0.2% against each, meaning it performs essentially on par with those older high-end parts.

The Intel Core i5-5257U, however, is the choice for users who need single-threaded performance and power efficiency. Its 41.3% single-core Geekbench lead is the largest margin in the entire comparison, and its 19.6% multicore Geekbench win shows that modern architecture can overcome a core-count deficit. The 28-watt TDP makes it suitable for compact or battery-powered systems, while the 14 nm process and 1,900 million transistors represent a much more advanced design. Its nearest rivals are the Intel Core i3-4150T and the AMD Athlon X4 840, with a delta of 0.1% against both, indicating it sits in a similar performance class as those parts.

For a desktop user running render farms or CPU-bound simulations, the i5-2405S is the clear pick. For a mobile user or anyone running mixed general-purpose workloads, the i5-5257U is the better option. The verdict from the database is that these two processors are not direct competitors; they serve different segments, and the benchmark results reflect their respective design philosophies. The i5-2405S wins on raw multi-threaded rendering, while the i5-5257U wins on modern efficiency and single-threaded responsiveness.