Intel Core i7-5550U vs Intel Xeon X3450 Comparison

The Intel Xeon X3450 and the Intel Core i7-5550U make for one of the stranger head-to-head pairings in the database: a 2009 server chip and a 2015 mobile chip that land, remarkably, in the same performance neighborhood. Both sit at the 22nd percentile versus all recorded CPUs, and their average benchmark scores sit within a few percent of each other, 837 for the Xeon against 813 for the Core i7. Yet the path each takes to that result could hardly be more different, and the recorded data tells a story of two design philosophies separated by six years and several process generations.

Head-to-Head Benchmarks

The headline finding is uniformity: the Xeon X3450 wins all five recorded Cinebench comparisons, and the margins are strikingly consistent. In Cinebench R15 multi-core the Xeon scores 245 against the Core i7's 238, a 2.9 percent lead. Cinebench R20 multi-core repeats the pattern almost exactly, 1021 versus 992, again a 2.9 percent margin. Cinebench R23 multi-core follows suit with 2431 against 2363, once more 2.9 percent.

That consistency alone is interesting, but the single-core results add a wrinkle worth investigating. The Xeon leads there too: 144 versus 139 in R20 single-core, a 3.6 percent gap, and 343 versus 333 in R23 single-core, a 3 percent gap. The implication is curious. The Xeon holds a slightly larger single-threaded advantage than multi-threaded one, which suggests the Core i7 is compensating in multi-core workloads, closing what its per-thread deficit would otherwise produce. Two cores and four threads keeping pace this closely with four cores and eight threads is the single most noteworthy fact in this comparison.

Context from the wider database sharpens the picture. The Xeon's average score of 837 places it nearly dead level with its nearest rivals: the Intel Core i5-5200U at 838 (just 0.1 percent ahead), the Intel Core i5-3380M at 838 (0.2 percent ahead), the Intel Core i5-3360M at 835 (0.2 percent behind), and the Intel Xeon X5470 at 839 (0.3 percent ahead). The Core i7-5550U's average of 813 is likewise bracketed by close peers: the Intel Core 2 Extreme QX9775 at 813 (a dead heat), the Intel Xeon X3440 at 815 (0.2 percent ahead), the Intel Core i5-L16G7 at 816 (0.4 percent ahead), and the AMD A10-6800K at 809 (0.5 percent behind). In other words, both chips occupy the same crowded mid-lower tier of the historical record, surrounded by processors from wildly different eras.

Architecture Differences

The architectural gap between these two is enormous by any measure. The Xeon X3450 is a Nehalem-family part, codenamed Lynnfield, built on Intel's 45 nm process. It packs 774 million transistors into a 296 mm² die, runs on Socket 1156, and carries a thermal envelope of 95 watts. Its clocks span 2.67 GHz base and 3.20 GHz boost. The Core i7-5550U belongs to the Broadwell generation, codenamed Broadwell-U, manufactured on a 14 nm process. Despite being far newer, it holds 1,900 million transistors in a die of just 133 mm², less than half the Xeon's silicon area, and operates within a 15 watt thermal envelope, roughly one-sixth of the Xeon's. It is soldered onto a BGA 1168 package rather than socketed.

Core counts diverge sharply. The Xeon offers 4 cores and 8 threads; the Core i7 offers 2 cores and 4 threads. Cache follows the same split: the Xeon carries 8 MB of shared L3, double the Core i7's 4 MB, while both share identical per-core L1 (64 KB) and L2 (256 KB) configurations. Memory support is DDR3 on dual-channel buses for both, but the Core i7 records higher theoretical bandwidth at 29.9 GB/s against the Xeon's 21.3 GB/s.

Feature differences matter too. The Xeon supports ECC memory, fitting its Server/Workstation market segment, and exposes 16 lanes of PCIe Gen 2. The Core i7 lacks ECC, offers 12 lanes of PCIe Gen 2, but includes integrated graphics, specifically Intel HD 6000, something the Xeon entirely omits. Neither part has an unlocked multiplier. Both are end-of-life products.

Where Each One Wins

The Xeon's case rests on raw throughput. It wins every recorded benchmark, multi-core and single-core alike, by roughly three percent. For sustained rendering workloads as measured by the Cinebench suite, the data shows the Xeon delivering modestly but consistently better results, and its doubled core count, doubled thread count, and doubled L3 cache give it headroom in parallel workloads beyond what these tests capture. Its ECC support also makes it the only option of the two suitable for error-correcting memory configurations.

The Core i7's case rests on efficiency and integration, not on any recorded benchmark victory, because it has none. What it does have is comparable performance, within three percent across the board, from a package with a 15 watt thermal envelope versus the Xeon's 95 watts. It also brings integrated graphics in the form of Intel HD 6000, which the Xeon cannot provide at all, and it fits mobile designs in a way a Socket 1156, 95-watt desktop-server chip never could. Its higher memory bandwidth figure, 29.9 GB/s versus 21.3 GB/s, is a further point in its favor where memory throughput is the constraint.

The Verdict

Strictly from the recorded data, the Xeon X3450 is the performance pick: five wins from five tests, margins of 2.9 to 3.6 percent, plus ECC support and twice the cores, threads, and shared L3 cache. The Core i7-5550U is the efficiency pick: essentially the same benchmark performance, a far smaller thermal envelope, integrated graphics, and a newer 14 nm process. Both parts are end-of-life, both sit at the 22nd percentile against the full database, and neither offers an unlocked multiplier. For a rendering or workstation role where every benchmark point counts, the Xeon is the data-backed choice. For a mobile or power-constrained role where a capable integrated GPU and low heat matter, the Core i7 is the only sensible option of the two. Neither is competitive against modern hardware, but against each other they are separated by less than the margin of many same-generation product tiers.

FAQ

Q: Which CPU is faster in Cinebench R23 multi-core? A: The Xeon X3450, scoring 2431 against the Core i7-5550U's 2363, a lead of 2.9 percent.

Q: Does the Core i7-5550U win any recorded benchmark? A: No. The Xeon X3450 wins all five head-to-head comparisons, though the largest gap is only 3.6 percent, in Cinebench R20 single-core (144 versus 139).

Q: How do their thermal envelopes compare? A: The Xeon X3450 is rated at 95 watts, while the Core i7-5550U is rated at 15 watts, so the mobile chip delivers near-parity performance at a fraction of the power draw.

Q: Which chip supports ECC memory? A: Only the Xeon X3450. The Core i7-5550U does not support ECC, consistent with its consumer mobile positioning.

Q: Do either of these CPUs include integrated graphics? A: The Core i7-5550U includes Intel HD 6000 graphics. The Xeon X3450 has no integrated graphics at all.

Q: How do they rank against the full database? A: Both sit at the 22nd percentile versus all recorded CPUs, with average benchmark scores of 837 for the Xeon and 813 for the Core i7.

Specification Differences

| Field | Intel Xeon X3450 | Intel Core i7-5550U |

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

| Architecture | Nehalem | Broadwell |

| Codename | Lynnfield | Broadwell-U |

| Cores | 4 | 2 |

| Threads | 8 | 4 |

| Base Clock | 2.67 GHz | 2.00 GHz |

| Boost Clock | 3.20 GHz | 3.00 GHz |

| TDP | 95 W | 15 W |

| Socket | Intel Socket 1156 | Intel BGA 1168 |

| Process Node | 45 nm | 14 nm |

| Transistors | 774 million | 1,900 million |

| Die Size | 296 mm² | 133 mm² |

| L3 Cache | 8 MB (shared) | 4 MB (shared) |

| Memory Bandwidth | 21.3 GB/s | 29.9 GB/s |

| ECC Memory | Yes | No |

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

| Integrated Graphics | None | Intel HD 6000 |

| Market Segment | Server/Workstation | Mobile |

| Release Date | 2009 | 2015 |

| Launch MSRP | $241 | $426 |

| Part Number | SLBLD | SR26A |

| Avg Benchmark Score | 837 | 813 |