Intel Core i5-3550S vs Intel Core i7-5557U Comparison

The Intel Core i5-3550S and Intel Core i7-5557U represent two very different design philosophies from Intel, separated by nearly three years of silicon evolution. The i5-3550S is a 65W desktop part built on the 22nm Ivy Bridge architecture, while the i7-5557U is a 28W mobile chip on the 14nm Broadwell-U process. Despite the i7 being a newer, higher-tier product, the benchmark data reveals a fascinating split: the desktop i5 dominates in every Cinebench test, while the mobile i7 wins decisively in Geekbench. The average benchmark scores are nearly identical—1118 for the i5 and 1110 for the i7—placing both at the 31st percentile among all CPUs, but the way they achieve those scores could not be more different.

Head-to-Head Benchmarks

The most striking pattern in the head-to-head data is the complete sweep by the Intel Core i5-3550S across the Cinebench suite. In Cinebench R15 multicore, the i5 scores 383 against the i7's 270, a 41.9% advantage. That margin is almost perfectly consistent across every Cinebench iteration: R20 multicore shows 1599 versus 1126 (42% delta), R23 multicore shows 3808 versus 2682 (42% delta), and even the single-core tests follow suit. In Cinebench R20 single-core, the i5 posts 225 against 158, a 42.4% lead; in R23 single-core, it's 537 versus 378, a 42.1% gap. This uniformity across both multi-threaded and single-threaded workloads suggests the i5-3550S has a fundamental architectural advantage in Cinebench's rendering engine, likely stemming from its four physical cores versus the i7's two.

The story flips entirely in Geekbench. The Intel Core i7-5557U wins Geekbench multicore with 2099 points against the i5's 1716, an 18.2% margin in the i7's favor. Even more dramatic is Geekbench single-core, where the i7 scores 1060 against the i5's 623—a 41.2% difference. This is a nearly exact reversal of the Cinebench deltas, and it highlights how differently these two benchmarks stress the hardware. The i5-3550S wins 5 of the 7 head-to-head tests, but the two Geekbench victories for the i7 are substantial enough to nearly equalize their average scores (1118 vs 1110).

The Cinebench wins are not marginal; they are consistent 40%+ blowouts across five separate tests. The Geekbench wins are equally lopsided in the opposite direction. This is a rare case where the "winner" depends entirely on which benchmark suite you trust. The i5-3550S's nearest rivals include the Intel Core i3-4150 (delta -0.1%), Intel Core i7-2860QM (delta -0.1%), and AMD Athlon 240GE (delta -0.2%), while the i7-5557U sits alongside the Intel Xeon E5630 (0% delta) and Intel Xeon E5-2609 v3 (0.1% delta). Both CPUs are clustered in the same performance tier, but their benchmark profiles are polar opposites.

Architecture Differences

The architectural gap between these two processors is substantial, starting with the manufacturing process. The i5-3550S uses Intel's 22nm node with 1,400 million transistors on a 160 mm² die, while the i7-5557U uses the newer 14nm node with 1,900 million transistors on a smaller 133 mm² die. This explains the power difference: the i5 has a 65W TDP, while the i7 sips just 28W. The i7's higher transistor count on a smaller die reflects the density improvements of the 14nm process, even though that process was still maturing in 2015.

Core configuration is where the fundamental performance split originates. The i5-3550S offers 4 cores and 4 threads, while the i7-5557U offers only 2 cores but 4 threads via Hyper-Threading. Both have identical L1 cache at 64 KB per core and L2 at 256 KB per core, but the shared L3 cache differs: the i5 has 6 MB shared, while the i7 has 4 MB shared. The i5 compensates for its older architecture with two extra physical cores and 50% more L3 cache, which explains its Cinebench dominance. The i7's clock speeds are actually competitive—3.10 GHz base and 3.40 GHz boost versus the i5's 3.00 GHz base and 3.70 GHz boost—but the i5's higher boost clock and extra cores win the day in rendering workloads.

Memory support is DDR3 for both, with dual-channel buses. However, the i7-5557U lists a memory bandwidth of 29.9 GB/s, a figure not provided for the i5. PCIe connectivity differs notably: the i5 supports PCIe Gen 3 with 16 lanes (CPU only), while the i7 supports PCIe Gen 2 with 12 lanes (CPU only). This reflects the i5's desktop positioning versus the i7's ultrabook/mobile targeting. The integrated graphics also diverge significantly: the i5 ships with Intel HD 2500, while the i7 includes Intel Iris 6100, a much more capable graphics solution. The i7 also carries a launch MSRP of $426, while no MSRP is listed for the i5.

Where Each One Wins

The Intel Core i5-3550S is the clear victor for multi-threaded rendering and compute workloads. Its 42% lead across all Cinebench R15, R20, and R23 tests—both multicore and singlecore—indicates that the four physical cores and larger L3 cache provide a decisive advantage in Cinema 4D's rendering engine. For users running Cinebench-class workloads, which include 3D rendering, video encoding, and other heavily threaded tasks, the i5-3550S delivers consistently higher performance. The fact that it wins single-core Cinebench by the same margin as multicore suggests this isn't just about core count; the i5's Ivy Bridge architecture handles Cinebench's instruction patterns more efficiently than Broadwell-U.

The Intel Core i7-5557U wins in Geekbench, a benchmark that emphasizes memory latency, branch prediction, and newer instruction set extensions. Its 41.2% lead in Geekbench single-core is particularly telling—the i7's Broadwell architecture, despite having only 2 cores, achieves far higher per-thread performance in this synthetic test. The i7 also wins Geekbench multicore by 18.2%, which is remarkable given it has half the physical cores. This suggests that for workloads similar to Geekbench's test patterns—which include encryption, compression, and image processing—the i7-5557U is the stronger choice. The i7 also benefits from its Iris 6100 integrated graphics, which would provide better iGPU performance for media consumption and light gaming compared to the i5's HD 2500.

Power efficiency is another clear win for the i7. With a 28W TDP versus the i5's 65W, the i7-5557U is designed for sustained mobile operation, while the i5 requires desktop-class cooling and power delivery. The i7's 14nm process and 1,900 million transistors demonstrate that Intel packed more complexity into a smaller, more efficient package. For mobile users, the i7 is the only viable choice—the i5's socket 1155 and 65W TDP make it unsuitable for laptops or ultrabooks.

The Verdict

The data presents a clear but nuanced verdict. If your priority is raw rendering performance in Cinebench-class applications, the Intel Core i5-3550S is the definitive winner. It leads by 41.9% to 42.4% across all five Cinebench tests, and its four physical cores provide headroom that the i7's two cores cannot match. The i5 also holds a slight edge in average benchmark score (1118 versus 1110), though both sit at the 31st percentile of all CPUs. This chip is better suited for desktop users who need dependable multi-core throughput for rendering, compilation, or scientific computing.

If your priority is Geekbench-style workloads or mobile operation, the Intel Core i7-5557U is the better choice. Its 18.2% multicore and 41.2% single-core Geekbench wins indicate superior per-thread performance and architectural efficiency in those test patterns. The i7 also offers the Iris 6100 integrated graphics, a 28W TDP for mobile use, and a newer 14nm process. Its launch MSRP was $426, and it is now marked as end-of-life, so it should be considered in the context of existing systems or discounted mobile platforms.

For a desktop user building or upgrading a socket 1155 system, the i5-3550S is the obvious pick. For a laptop user seeking the best Geekbench performance per watt, the i7-5557U wins decisively. There is no universal champion—the benchmark data splits cleanly along architectural lines, and the correct choice depends entirely on which benchmark suite reflects your actual workload.

FAQ

Q: Which CPU has more physical cores?

A: The Intel Core i5-3550S has 4 cores and 4 threads, while the Intel Core i7-5557U has 2 cores and 4 threads (using Hyper-Threading).

Q: Why does the i5-3550S win all Cinebench tests?

A: The i5 leads by 41.9% to 42.4% across R15, R20, and R23 multicore and singlecore tests, likely due to its two extra physical cores and 6 MB of shared L3 cache versus the i7's 4 MB.

Q: How much faster is the i7-5557U in Geekbench single-core?

A: The i7 scores 1060 against the i5's 623, a 41.2% advantage. It also wins Geekbench multicore with 2099 versus 1716, an 18.2% lead.

Q: What are the TDP ratings for each processor?

A: The i5-3550S has a 65W TDP, while the i7-5557U has a much lower 28W TDP, reflecting its mobile design.

Q: Do both CPUs support the same memory type?

A: Yes, both support DDR3 with dual-channel buses. The i7-5557U lists a memory bandwidth of 29.9 GB/s; no bandwidth figure is provided for the i5.

Q: What is the average benchmark score difference between them?

A: The i5-3550S has an average benchmark score of 1118, while the i7-5557U scores 1110—a negligible 0.7% difference, placing both at the 31st percentile of all CPUs.