Intel Core i9-7940X vs Intel Xeon W-2170B Comparison

The Intel Core i9-7940X and the Intel Xeon W-2170B are two 14-core, 28-thread processors built on the same 14 nm Skylake architecture, yet they target entirely different market segments. Benchmark data shows the Core i9-7940X winning all six head-to-head comparisons, with a consistent margin of roughly 3.6% to 3.7% across both single-core and multi-core workloads. The Xeon W-2170B, however, counters with features the desktop part lacks: ECC memory support and two additional PCIe lanes. The data suggests a clear performance hierarchy, but the choice between them depends on whether raw compute speed or platform reliability features matter more.

The Verdict

The benchmark results are unambiguous: the Intel Core i9-7940X wins every single head-to-head test in the data set. The largest margin comes in single-core tests, where it leads by 3.7% in both Cinebench R15 and R20, while multi-core tests show a consistent 3.6% advantage across R15, R20, and R23. This translates to a 751-point lead in Cinebench R23 multi-core (21444 vs 20693) and a 106-point lead in single-core (3027 vs 2921). The average benchmark score reinforces this, with the Core i9-7940X sitting at 6147 compared to the Xeon's 5985, a difference of 162 points.

The Xeon W-2170B's only advantages are qualitative, not performance-based. It supports ECC memory, which the Core i9-7940X does not, and it offers 48 PCIe Gen 3 lanes versus 44 on the desktop chip. It also has a lower TDP of 140 watts compared to 165 watts. For users who prioritize error-correcting memory in a workstation or server environment, the Xeon is the logical pick despite its lower benchmark scores. For anyone building a high-end desktop where compute speed is paramount, the Core i9-7940X is the data-backed winner, especially considering its unlocked multiplier allows for overclocking while the Xeon's is locked.

Architecture Differences

Both processors share the same fundamental Skylake design, fabricated on Intel's 14 nm process with a die size of 484 mm². The core configuration is identical: 14 cores, 28 threads, 64 KB of L1 cache per core, 1 MB of L2 cache per core, and 19.25 MB of shared L3 cache. The memory subsystem is also the same on paper, with DDR4 support, a quad-channel memory bus, and 85.3 GB/s of memory bandwidth.

The divergence begins with the codename and market positioning. The Core i9-7940X is part of the Skylake-X family, classified as a 7th Gen Core i9 X-Series desktop processor. The Xeon W-2170B belongs to the Skylake-W family, explicitly labeled as a Server/Workstation part. This distinction drives several key differences in features. The Xeon supports ECC memory, a critical requirement for data integrity in server workloads, while the Core i9 does not. The Xeon also provides 48 PCIe Gen 3 lanes from the CPU, four more than the Core i9's 44 lanes. The Core i9-7940X has an unlocked multiplier for overclocking, whereas the Xeon W-2170B's multiplier is locked.

The release dates differ by roughly four months, with the Core i9 launching on 2017-08-31 and the Xeon on 2017-12-20. Both are end-of-life products. The Core i9-7940X carries a launch MSRP of $1399, while no launch price is listed for the Xeon W-2170B.

Head-to-Head Benchmarks

The six head-to-head benchmarks all favor the Intel Core i9-7940X, with a remarkably consistent margin. In Cinebench R15 multi-core, the Core i9 scores 2161 against the Xeon's 2085, a 3.6% difference. The single-core R15 test shows a 3.7% lead, with scores of 305 and 294 respectively. Moving to Cinebench R20, the pattern holds: multi-core scores are 9006 versus 8691 (3.6% delta), and single-core scores are 1271 versus 1226 (3.7% delta).

The Cinebench R23 results mirror the earlier tests almost exactly. The Core i9-7940X posts a multi-core score of 21444, while the Xeon W-2170B manages 20693, again a 3.6% difference. Single-core R23 scores are 3027 and 2921, a 3.6% delta. The consistency of these margins across different Cinebench versions suggests the performance gap is structural rather than workload-specific, likely stemming from the Core i9's higher base clock of 3.10 GHz versus the Xeon's 2.50 GHz, and its slightly higher boost clock of 4.40 GHz versus 4.30 GHz.

The Geekbench results are only available for the Core i9-7940X, which scores 10516 in multi-core and 1445 in single-core. No Geekbench data is listed for the Xeon W-2170B, so a direct comparison in that test is not possible from the available facts.

Specification Differences

The two processors differ in several specification fields, despite sharing their core architecture and cache layout. The most significant differences are in clock speeds, power, and platform features:

• Base Clock: The Core i9-7940X runs at 3.10 GHz, while the Xeon W-2170B is clocked lower at 2.50 GHz.
• Boost Clock: The Core i9-7940X boosts to 4.40 GHz, slightly ahead of the Xeon's 4.30 GHz.
• TDP: The Core i9-7940X has a 165-watt TDP, while the Xeon W-2170B is rated at 140 watts.
• ECC Memory: The Xeon W-2170B supports ECC memory; the Core i9-7940X does not.
• PCIe Lanes: The Xeon W-2170B provides 48 PCIe Gen 3 lanes (CPU only), while the Core i9-7940X offers 44 lanes.
• Multiplier: The Core i9-7940X has an unlocked multiplier; the Xeon W-2170B's multiplier is locked.
• Market Segment: The Core i9-7940X is a Desktop part; the Xeon W-2170B is a Server/Workstation part.
• Release Date: The Core i9-7940X launched on 2017-08-31; the Xeon W-2170B followed on 2017-12-20.
• Part Number: The Core i9-7940X is SR3RQ; the Xeon W-2170B is SR3W3.

The socket, process node, foundry, die size, cache hierarchy, memory support, memory bus, and memory bandwidth are identical between the two.

FAQ

Q: Which processor has a higher boost clock?

A: The Intel Core i9-7940X boosts to 4.40 GHz, while the Intel Xeon W-2170B reaches 4.30 GHz.

Q: Does the Xeon W-2170B support ECC memory?

A: Yes, the Xeon W-2170B supports ECC memory. The Core i9-7940X does not support ECC memory.

Q: How many PCIe lanes does each processor provide?

A: The Xeon W-2170B provides 48 PCIe Gen 3 lanes from the CPU, while the Core i9-7940X provides 44 lanes.

Q: What is the performance difference in Cinebench R23 multi-core?

A: The Core i9-7940X scores 21444, which is 3.6% higher than the Xeon W-2170B's score of 20693.

Q: Are both processors based on the same architecture?

A: Yes, both are based on the Skylake architecture, using the same 14 nm process and 484 mm² die size, with identical cache configurations.

Q: Which processor has an unlocked multiplier?

A: The Core i9-7940X has an unlocked multiplier, while the Xeon W-2170B's multiplier is locked.

Where Each One Wins

The Intel Core i9-7940X wins in every benchmark category recorded. It is ahead in all Cinebench R15, R20, and R23 tests, both single-core and multi-core. The consistent 3.6% to 3.7% margin suggests that the higher base and boost clocks provide a uniform advantage across all types of compute tasks. With its unlocked multiplier, the Core i9-7940X also offers the potential for further performance gains through overclocking, which is not available on the Xeon. The data shows this processor is the clear choice for raw throughput in desktop applications, with an average benchmark score of 6147.

The Intel Xeon W-2170B wins in platform features, not performance. Its ECC memory support is a decisive factor for workloads where memory errors are unacceptable, such as financial modeling or scientific computing. The additional four PCIe lanes (48 versus 44) provide more headroom for expansion cards, making it better suited for dense workstation configurations with multiple GPUs or high-speed storage controllers. The lower TDP of 140 watts versus 165 watts also makes it more power-efficient under load. While it loses all six head-to-head benchmarks, its average score of 5985 places it in the same percentile (61st) as the Core i9-7940X, indicating that the performance gap is modest in the broader context of all CPUs. The Xeon's locked multiplier is a limitation for enthusiasts but irrelevant for server stability, where the ability to guarantee consistent operation is paramount.