Intel Atom x7405C vs Intel Core i9-7940X Comparison

Head-to-Head Benchmarks

The recorded data shows a complete sweep for the Intel Core i9-7940X across all six shared benchmark tests, with no wins recorded for the Intel Atom x7405C. The margins are substantial in every case, reflecting the fundamental difference in positioning between these two processors.

In Cinebench R15, the Core i9-7940X scores 2161 in multi-core against 446 for the Atom x7405C, a 384.5% advantage. The single-core test tells a similar story: 305 versus 62, a 391.9% lead for the i9-7940X. These are not close contests; the desktop part outperforms the mobile Atom by nearly five times in single-threaded rendering.

Moving to Cinebench R20, the pattern holds. The i9-7940X posts 9006 in multi-core versus 1862 for the Atom x7405C, a 383.7% gap. Single-core results show 1271 against 262, a 385.1% difference. The relative performance advantage remains remarkably consistent, hovering around the 384-392% range across all tests, which suggests the gap is structural rather than workload-specific.

Cinebench R23, the most modern rendering workload in the database, shows the same dominance. The Core i9-7940X achieves 21444 multi-core and 3027 single-core, while the Atom x7405C manages 4435 and 626 respectively. The multi-core delta is 383.5%, and the single-core delta is also 383.5%. This consistency across three generations of Cinebench indicates that the performance relationship between these two chips is stable regardless of the rendering engine's optimization level.

Where Each One Wins

The Core i9-7940X wins every benchmark where both processors have recorded scores. That includes all six Cinebench tests spanning R15, R20, and R23, in both multi-core and single-core configurations. The Atom x7405C has no head-to-head wins in the database.

The Atom x7405C does have additional PassMark tests recorded that the i9-7940X lacks, but these cannot be compared directly since there are no corresponding scores for the Core i9 in those workloads. The PassMark data for the Atom shows strength in data compression (56317), integer math (14669), and floating-point math (9063), but these figures stand alone without a rival score from the i9-7940X.

For use-case analysis, the benchmark results indicate that the Core i9-7940X is the clear choice for rendering workloads, video encoding, compilation, or any task that scales with multi-threaded performance. Its 28 threads and 14 cores provide massive parallel throughput. The Atom x7405C, with 4 cores and 4 threads, is suited for low-power embedded or edge applications where the 12-watt TDP is more important than raw compute, but the data shows it cannot compete on performance.

Architecture Differences

The two processors come from entirely different Intel design families. The Core i9-7940X uses the Skylake-X architecture on a 14 nm process node, with a die size of 484 mm². It belongs to the Core i9 X-Series 7th Generation lineup. The Atom x7405C uses the Amston Lake architecture with the Gracemont core design, built on a 10 nm process node.

Core counts differ dramatically: the i9-7940X has 14 cores and 28 threads, while the Atom x7405C has 4 cores and 4 threads. The desktop chip lacks hyper-threading on the Atom, so its thread count equals its core count. The i9-7940X also has an unlocked multiplier, whereas the Atom is locked.

Cache layouts are distinct. The i9-7940X provides 64 KB of L1 per core, 1 MB of L2 per core, and 19.25 MB of shared L3. The Atom x7405C offers 96 KB of L1 per core, 2 MB of shared L2, and 6 MB of shared L3. The Atom's per-core L1 is larger, but the total cache pool is far smaller.

Memory support differs substantially. The i9-7940X uses DDR4 with a quad-channel memory bus and 85.3 GB/s of bandwidth. The Atom x7405C supports both DDR4 and DDR5, but only on a single-channel bus with 38.4 GB/s of bandwidth. Neither processor supports ECC memory. PCIe capabilities also diverge: the i9-7940X provides Gen 3 with 44 lanes, while the Atom x7405C provides Gen 3 with 9 lanes.

The production status separates them further. The i9-7940X is end-of-life and was released in August 2017. The Atom x7405C is active and was released in April 2024. The Core i9 targets the desktop market segment, while the Atom is classified as mobile. The i9-7940X has no integrated graphics, and the Atom lists N/A for integrated graphics as well.

The Verdict

The data is unambiguous. The Intel Core i9-7940X outperforms the Intel Atom x7405C by roughly 384-392% in every shared benchmark. This is not a marginal difference or a workload-specific outcome; it is a consistent, sweeping victory across all six Cinebench tests.

The Core i9-7940X should be selected by anyone whose workload demands high multi-threaded throughput. Its 14 cores, 28 threads, quad-channel memory, and 44 PCIe lanes make it a capable desktop workstation processor. The benchmark scores confirm it sits in the 61st percentile of all CPUs, with nearest rivals including the AMD EPYC 7501 (0.3% ahead), AMD EPYC 7272 (0.6% behind), AMD Ryzen Threadripper 1950X (1.4% behind), and AMD Ryzen 3 3100U (1.6% behind). Its average benchmark score is 6147.

The Atom x7405C, despite its much lower performance, holds a 62nd percentile ranking among all CPUs, driven by its PassMark scores in specific workloads. Its nearest rivals include the Intel Core i5-13500E (0.3% ahead), Intel Core i9-7960X (0.5% behind), Intel Core i9-10940X (0.6% behind), and Intel Pentium Gold G6405 (0.6% behind). The average benchmark score is 6568, which actually exceeds the i9-7940X's 6147 because the Atom has additional PassMark tests that boost its average.

The choice between these two depends entirely on the requirement profile. For raw compute, rendering, or compilation, the Core i9-7940X is the only option. For low-power, embedded, or mobile use cases where the 12-watt TDP and compact BGA package matter, the Atom x7405C serves a different purpose. The benchmark data cannot recommend the Atom for performance-sensitive tasks, but its power envelope and form factor are not captured in the scores.

FAQ

Q: Which processor has a higher multi-core score in Cinebench R23?

A: The Intel Core i9-7940X scores 21444 in Cinebench R23 multi-core, compared to 4435 for the Intel Atom x7405C, a 383.5% advantage.

Q: What is the single-core performance difference in Cinebench R20?

A: The Core i9-7940X achieves 1271 in Cinebench R20 single-core, while the Atom x7405C scores 262, giving the i9 a 385.1% lead.

Q: How many cores and threads does each processor have?

A: The Core i9-7940X has 14 cores and 28 threads. The Atom x7405C has 4 cores and 4 threads.

Q: What memory configurations do the two processors support?

A: The Core i9-7940X supports DDR4 with a quad-channel memory bus and 85.3 GB/s bandwidth. The Atom x7405C supports both DDR4 and DDR5, but only on a single-channel bus with 38.4 GB/s bandwidth.

Q: Which processor has a higher average benchmark score?

A: The Atom x7405C has an average benchmark score of 6568, while the Core i9-7940X has an average of 6147. However, the Atom's average includes PassMark tests that the i9 does not have recorded, so the comparison is not apples-to-apples.

Q: Are both processors still in production?

A: No. The Core i9-7940X is end-of-life, with a release date of August 2017. The Atom x7405C is active, with a release date of April 2024.

Specification Differences

| Specification | Intel Core i9-7940X | Intel Atom x7405C |

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

| Cores | 14 | 4 |

| Threads | 28 | 4 |

| Base Clock | 3.10 GHz | 1.70 GHz |

| Boost Clock | 4.40 GHz | 3.40 GHz |

| TDP | 165 W | 12 W |

| Socket | Intel Socket 2066 | Intel BGA 1264 |

| Architecture | Skylake | Amston Lake |

| Codename | Skylake-X | Amston Lake |

| Generation | Core i9 (X-Series 7th Gen) | Atom (Gracemont) |

| Process Node | 14 nm | 10 nm |

| Die Size | 484 mm² | Not listed |

| L1 Cache | 64 KB (per core) | 96 KB (per core) |

| L2 Cache | 1 MB (per core) | 2 MB (shared) |

| L3 Cache | 19.25 MB (shared) | 6 MB (shared) |

| Memory Support | DDR4 | DDR4, DDR5 |

| Memory Bus | Quad-channel | Single-channel |

| Memory Bandwidth | 85.3 GB/s | 38.4 GB/s |

| PCIe | Gen 3, 44 Lanes (CPU only) | Gen 3, 9 Lanes (CPU only) |

| Integrated Graphics | None | N/A |

| Market Segment | Desktop | Mobile |

| Production Status | End-of-life | Active |

| Release Date | August 2017 | April 2024 |

| Launch MSRP | $1399 | $57 |

| Unlocked Multiplier | Yes | No |

| Part Number | SR3RQ | SRNEM |