Intel Core i7-5775C vs Intel Xeon D-1557 Comparison

Head-to-Head Benchmarks

The recorded data shows a consistent pattern across all Cinebench workloads: the Intel Xeon D-1557 wins every head-to-head comparison against the Intel Core i7-5775C. In Cinebench R15 multi-core, the Xeon scores 795 versus the Core i7’s 660, a 20.5% advantage. The single-core R15 result is similar, 112 versus 93, translating to a 20.4% lead. This margin is not a fluke of a single test version; it repeats almost exactly in newer Cinebench releases. In R20 multi-core, the Xeon posts 3314 against 2750, again 20.5% ahead. The single-core R20 gap is 467 versus 388, or 20.4%. Moving to R23, the multi-core score is 7892 versus 6549 (20.5% delta), and the single-core score is 1114 versus 924 (20.6% delta).

The near-identical delta percentages across all six tests are striking. Whether the workload is single-threaded or multi-threaded, the relative performance gap stays fixed within a narrow band of 20.4% to 20.6%. This suggests the difference is not tied to core count scaling but rather to a fundamental per-thread efficiency advantage in the Xeon D-1557. The benchmark results indicate that the Xeon’s higher base clock, despite its lower boost clock, does not hurt it in lightly threaded tasks. The Xeon’s base clock is 1500 MHz versus the Core i7’s 3300 MHz, yet the Xeon still wins single-core tests by over 20%. That is counterintuitive until one considers the architecture and memory subsystem differences.

In absolute terms, the Xeon’s multi-core advantage in R23 is 1343 points, which is a substantial gap for a 12-core part versus a 4-core part. The Core i7-5775C, with its 4 cores and 8 threads, would normally be expected to lose heavily in multi-threaded rendering, but the Xeon’s win is moderate, not overwhelming. This indicates that the Core i7’s higher clock speed (3700 MHz boost) partially compensates for its lower core count. However, the Xeon’s 12 cores and 24 threads still prevail. The single-core wins are more surprising: a 20.4% lead for a 1500 MHz base chip over a 3300 MHz base chip. This points to the Xeon’s larger L3 cache allocation (1.5 MB per core) and possibly better memory latency characteristics in the benchmark environment.

The aggregate benchmark score, which averages all recorded tests, also favors the Xeon. The Xeon D-1557 has an average benchmark score of 2282, while the Core i7-5775C sits at 2224. That difference is only 2.6%, far smaller than any individual Cinebench delta. The reason is the Core i7 has additional Geekbench scores in the database, which are not present for the Xeon. The Core i7’s Geekbench multi-core score is 4989 and single-core is 1441, and these pull its average upward relative to the Cinebench-only dataset for the Xeon. When comparing like-for-like Cinebench workloads, the Xeon is consistently ahead, but the overall database average narrows the gap because of test coverage differences.

Where Each One Wins

The Xeon D-1557 wins every benchmark in the head-to-head set, so the use-case split is defined by the magnitude of the win rather than the winner. In multi-threaded rendering workloads, the Xeon’s lead is 20.5% across all Cinebench multi-core tests. This makes it the clear choice for server or workstation tasks that saturate all available threads, such as video encoding, 3D scene rendering, or scientific computation. The 12-core, 24-thread configuration provides twice the logical threads of the Core i7, and the benchmark data confirms this translates into a measurable, though not massive, advantage. The Core i7-5775C, with its 4 cores and 8 threads, would be less suitable for heavily parallel workloads, but its higher clocks mean it does not fall as far behind as a simple core count comparison would suggest.

In single-threaded tasks, the Xeon also wins, with a 20.4% to 20.6% lead depending on the Cinebench version. This is unexpected for a low-power server chip, but the data is unambiguous. The Xeon’s per-core L3 cache of 1.5 MB, combined with its architecture, yields higher per-thread performance than the Core i7’s shared 6 MB L3. The Core i7-5775C does have an integrated GPU (Iris Pro Graphics 6200), which the Xeon lacks. For desktop use cases where the integrated GPU is sufficient, the Core i7 could avoid a discrete graphics card, but the database benchmarks do not cover GPU performance, so no conclusion can be drawn about that advantage. In terms of CPU-only workloads, the Xeon wins every recorded test.

The market segment separation reinforces this split. The Xeon is classified as Server/Workstation, while the Core i7 is Desktop. The Xeon supports ECC memory, making it suitable for data integrity-sensitive environments; the Core i7 does not support ECC. The Xeon also has more PCIe lanes (24 versus 16), which benefits server configurations with multiple expansion cards. The Core i7 has a higher TDP (65 watts versus 45 watts) and a higher boost clock (3700 MHz versus 2100 MHz), but the benchmark results do not reflect a performance advantage from those specs. The Core i7’s only unique advantage in the database is its Geekbench scores, which are not part of the head-to-head comparison. Those scores (4989 multi-core, 1441 single-core) are not directly comparable to the Xeon’s Cinebench results, so they do not indicate a win in any shared workload.

Architecture Differences

Both processors are built on Intel’s 14 nm process and use the Broadwell architecture. The Xeon D-1557 is part of the Broadwell-DE generation, a derivative optimized for dense server deployments. The Core i7-5775C is a mainstream desktop Broadwell part. The Xeon has 12 cores and 24 threads, while the Core i7 has 4 cores and 8 threads. This core count difference is the most significant architectural divergence. The Xeon’s die size is 246 mm², and it contains 3,200 million transistors. The Core i7’s die size is smaller at 182 mm², and its transistor count is not recorded in the database.

Cache organization differs substantially. The Xeon allocates 64 KB of L1 per core and 256 KB of L2 per core, same as the Core i7. However, the L3 cache configuration is different: the Xeon provides 1.5 MB per core, while the Core i7 has a shared 6 MB L3 pool. For a 4-core part, 6 MB shared means roughly 1.5 MB per core, but the sharing mechanism is fundamentally different. The Xeon’s per-core L3 allocation is designed for isolated server workloads, whereas the Core i7’s shared L3 allows any core to access the entire 6 MB. The Xeon’s total L3 is not listed as a single figure, but with 1.5 MB per core across 12 cores, it would be 18 MB. The database does not provide a totalL3 value for either part.

Memory support is another key difference. The Xeon supports both DDR3 and DDR4 memory, while the Core i7 supports only DDR3. Both use a dual-channel memory bus. The Core i7 has a recorded memory bandwidth of 25.6 GB/s; the Xeon’s memory bandwidth is not listed. The Xeon supports ECC memory, which is critical for error-correcting workloads; the Core i7 does not. The Xeon also has 24 PCIe Gen 3 lanes (CPU only), while the Core i7 has 16 PCIe Gen 3 lanes. The Core i7 includes integrated graphics (Iris Pro Graphics 6200), while the Xeon has no integrated GPU. The Xeon uses the Intel BGA 1667 socket, while the Core i7 uses Intel Socket 1150. The Xeon’s multiplier is locked, while the Core i7’s multiplier is unlocked, allowing overclocking on the desktop part.

Specification Differences

The table below lists only the fields where the two processors differ, as recorded in the database.

| Specification | Intel Xeon D-1557 | Intel Core i7-5775C |

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

| Cores | 12 | 4 |

| Threads | 24 | 8 |

| Base Clock | 1500 MHz | 3300 MHz |

| Boost Clock | 2100 MHz | 3700 MHz |

| TDP | 45 W | 65 W |

| Socket | Intel BGA 1667 | Intel Socket 1150 |

| Generation | Xeon D (Broadwell-DE) | Core i7 (Broadwell) |

| Die Size | 246 mm² | 182 mm² |

| Transistors | 3,200 million | Not recorded |

| L3 Cache | 1.5 MB per core | 6 MB shared |

| Memory Support | DDR3, DDR4 | DDR3 |

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

| ECC Memory | Yes | No |

| PCIe Lanes | Gen 3, 24 lanes | Gen 3, 16 lanes |

| Integrated Graphics | None | Iris Pro Graphics 6200 |

| Market Segment | Server/Workstation | Desktop |

| Release Date | 2016-02-23 | 2015-05-14 |

| Launch MSRP | $694 | $366 |

| Multiplier Unlocked | No | Yes |

| Part Number | SR2M4 | SR2AG |

The Xeon has triple the cores and triple the threads of the Core i7. Its base clock is less than half of the Core i7’s, but its boost clock is only 1600 MHz lower. The Xeon’s TDP is 20 watts lower, a notable efficiency advantage given its higher core count. The Xeon supports both DDR3 and DDR4, while the Core i7 is limited to DDR3. The Xeon has 8 additional PCIe lanes. The Core i7 is the only one with integrated graphics. The Xeon was released about nine months later, and its launch MSRP is higher at $694 versus $366.

FAQ

Q: Which processor wins in Cinebench R23 multi-core?

A: The Intel Xeon D-1557 scores 7892 versus the Intel Core i7-5775C’s 6549, a 20.5% advantage.

Q: Does the Core i7-5775C win any benchmark in the head-to-head comparison?

A: No. The Xeon D-1557 wins all six recorded head-to-head benchmarks, with no wins for the Core i7.

Q: Why does the Xeon win single-core tests despite its lower clock speed?

A: The Xeon’s base clock is 1500 MHz versus the Core i7’s 3300 MHz, yet the Xeon leads single-core R23 by 20.6%. The database does not provide a direct explanation, but the per-core L3 cache allocation (1.5 MB per core) and architecture likely contribute.

Q: Do the two processors support the same memory types?

A: No. The Xeon supports DDR3 and DDR4, while the Core i7 supports only DDR3. The Xeon also supports ECC memory, which the Core i7 does not.

Q: What is the average benchmark score difference?

A: The Xeon D-1557 has an average benchmark score of 2282, while the Core i7-5775C has 2224. The difference is 2.6%, but the Core i7 includes Geekbench scores that the Xeon lacks.

Q: Which processor has more PCIe lanes?

A: The Xeon D-1557 has 24 PCIe Gen 3 lanes, while the Core i7-5775C has 16 PCIe Gen 3 lanes.