Intel Core i7-5820K vs Intel Xeon W-2125 Comparison

Head-to-Head Benchmarks

The benchmark data presents a clear split between the two processors. The Intel Xeon W-2125 wins seven of the eight head-to-head comparisons, while the Intel Core i7-5820K claims a single, but significant, victory. The most striking result is in Geekbench multicore, where the i7-5820K scores 5464 against the Xeon’s 4988, a 9.5% advantage. This is the largest delta in either direction across the entire benchmark suite.

In the Cinebench tests, the Xeon W-2125 consistently edges out the i7-5820K, though by narrow margins. In Cinebench R15 multicore, the Xeon scores 852 versus 841, a 1.3% difference. The single-core R15 result is similarly close: 120 versus 118, a 1.7% gap. Moving to Cinebench R20, the Xeon leads 3551 to 3508 in multicore and 501 to 495 in single-core, both showing a 1.2% delta. The pattern repeats in Cinebench R23, where the Xeon’s 8455 multicore score tops the i7-5820K’s 8354 by 1.2%, and its 1193 single-core score beats 1179 by the same margin.

The Geekbench single-core test flips the multicore result dramatically. Here, the Xeon W-2125 posts 1323 against the i7-5820K’s 1174, a substantial 11.3% lead. This is the Xeon’s largest winning margin and highlights a fundamental performance characteristic: the Xeon is notably stronger in single-threaded workloads, while the i7-5820K holds a solid edge in the Geekbench multicore metric.

Overall, the average benchmark scores are nearly identical — 2642 for the i7-5820K and 2623 for the Xeon W-2125. Both processors sit at the 49th percentile among all CPUs, placing them squarely in the mid-range of the performance spectrum. The nearest rival data reinforces this parity: the i7-5820K’s closest competitor, the Intel Xeon E-2274G, matches its average score exactly with a 0% delta, while the Xeon W-2125’s nearest rival, the Intel Core i7-1195G7, is 0.6% ahead. The two processors themselves are separated by just 0.7% in average score, with the i7-5820K slightly ahead.

Architecture Differences

The architectural divide between these two processors is substantial, reflecting their different release periods and market targets. The Intel Core i7-5820K is built on the Haswell architecture, specifically the Haswell-E variant, using a 22 nm process node. It packs 2,600 million transistors into a 356 mm² die. The Intel Xeon W-2125, by contrast, uses the Skylake architecture (Skylake-W) on a 14 nm process, with a significantly larger 484 mm² die; its transistor count is not specified in the data.

Core configuration differs markedly. The i7-5820K offers 6 cores and 12 threads, while the Xeon W-2125 provides 4 cores and 8 threads. This gives the i7-5820K a 50% advantage in core count and a 50% advantage in thread count. Cache hierarchies also diverge: both share 64 KB of L1 cache per core, but the i7-5820K has 256 KB of L2 per core versus 1 MB per core on the Xeon. Total L3 cache is 15 MB shared on the i7-5820K and 8.25 MB shared on the Xeon.

Clock speeds tell the opposite story. The i7-5820K has a base clock of 3.30 GHz and a boost clock of 3.60 GHz. The Xeon W-2125 runs at 4.00 GHz base and 4.50 GHz boost, giving it a 21% higher base clock and a 25% higher boost clock. This clock advantage directly explains the Xeon’s single-core benchmark superiority.

Memory support is similar in type — both use DDR4 with quad-channel memory buses — but bandwidth differs: the i7-5820K achieves 68.3 GB/s, while the Xeon W-2125 reaches 85.3 GB/s, a 25% improvement. ECC memory support is exclusive to the Xeon, which is a critical feature for workstation reliability. PCIe connectivity also favors the Xeon: it provides Gen 3 with 48 lanes (CPU only) versus the i7-5820K’s Gen 3 with 28 lanes.

The production status for both is end-of-life. The i7-5820K launched on 2014-08-31, while the Xeon W-2125 arrived on 2017-08-28, a three-year gap. The Xeon carries a launch MSRP of $444. The i7-5820K has an unlocked multiplier, enabling overclocking, while the Xeon’s multiplier is locked. The market segments differ as expected: the i7-5820K targets desktop users, while the Xeon is aimed at server and workstation environments.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Core i7-5820K has 6 cores and 12 threads, while the Intel Xeon W-2125 has 4 cores and 8 threads.

Q: What is the Geekbench multicore score difference between the two?

A: The i7-5820K scores 5464 in Geekbench multicore, which is 9.5% higher than the Xeon W-2125’s 4988.

Q: Does the Xeon W-2125 support ECC memory?

A: Yes, the Xeon W-2125 supports ECC memory, while the i7-5820K does not.

Q: Which processor has a higher boost clock?

A: The Xeon W-2125 has a boost clock of 4.50 GHz, compared to 3.60 GHz on the i7-5820K.

Q: Are both processors still in production?

A: No, both are listed as end-of-life production status.

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

A: The i7-5820K has an average benchmark score of 2642, and the Xeon W-2125 has an average of 2623.

Specification Differences

| Specification | Intel Core i7-5820K | Intel Xeon W-2125 |

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

| Cores | 6 | 4 |

| Threads | 12 | 8 |

| Base Clock | 3.30 GHz | 4.00 GHz |

| Boost Clock | 3.60 GHz | 4.50 GHz |

| TDP | 140 W | 120 W |

| Socket | Intel Socket 2011-3 | Intel Socket 2066 |

| Architecture | Haswell | Skylake |

| Codename | Haswell-E | Skylake-W |

| Process Node | 22 nm | 14 nm |

| Transistors | 2,600 million | Not specified |

| Die Size | 356 mm² | 484 mm² |

| L2 Cache | 256 KB (per core) | 1 MB (per core) |

| L3 Cache | 15 MB (shared) | 8.25 MB (shared) |

| Memory Bandwidth | 68.3 GB/s | 85.3 GB/s |

| ECC Memory | No | Yes |

| PCIe | Gen 3, 28 Lanes (CPU only) | Gen 3, 48 Lanes (CPU only) |

| Release Date | 2014-08-31 | 2017-08-28 |

| Launch MSRP | Not specified | $444 |

| Multiplier Unlocked | Yes | No |

| Part Number | SR20S | SR3LM |

| Market Segment | Desktop | Server/Workstation |

Where Each One Wins

The Intel Core i7-5820K is the clear winner in the Geekbench multicore test, posting a 9.5% advantage over the Xeon W-2125. This result is driven by its higher core and thread count — 6 cores and 12 threads versus 4 and 8. For workloads that scale well across multiple threads, such as video rendering, 3D modeling, or other parallel compute tasks, the i7-5820K demonstrates a measurable performance edge. Its larger 15 MB shared L3 cache also provides a capacity advantage that can benefit certain data-heavy workloads. Additionally, the unlocked multiplier makes it a candidate for overclocking, offering potential headroom beyond stock performance for users willing to invest in cooling and tuning.

The Intel Xeon W-2125 wins the remaining seven benchmark comparisons, albeit mostly by narrow margins. Its single-core performance is notably superior, with an 11.3% lead in Geekbench single-core (1323 versus 1174) and consistent 1.2–1.7% advantages across all three Cinebench single-core tests. This stems from its significantly higher clock speeds — 4.00 GHz base and 4.50 GHz boost versus 3.30 GHz and 3.60 GHz. For single-threaded applications, legacy software, or tasks that depend heavily on per-core performance, the Xeon is the stronger choice. Its 85.3 GB/s memory bandwidth, 25% higher than the i7-5820K, also supports memory-intensive operations. The Xeon’s ECC memory support and 48 PCIe lanes make it suitable for workstation environments requiring data integrity and extensive I/O expansion.

The Cinebench multicore results favor the Xeon, though only by about 1.2–1.3% in each version. This is counterintuitive given the i7-5820K’s core advantage, but the Xeon’s higher clocks and newer architecture offset the core deficit in these specific workloads. Both processors sit at the 49th percentile among all CPUs, and their average benchmark scores differ by less than 1%, indicating that for general mixed-use scenarios, either processor would deliver broadly comparable results. The choice ultimately hinges on workload type: the i7-5820K for parallel multicore Geekbench-style tasks, and the Xeon W-2125 for single-threaded performance, ECC reliability, and PCIe expansion capacity.