CPU Comparison

The Intel Core i9-10940X and the Intel Atom x7405C represent two extremes of Intel’s product stack, and the benchmark data shows a complete dominance by the former across every shared test. The Core i9-10940X, a 14-core, 28-thread desktop part from the Cascade Lake-X series, outscores the 4-core, 4-thread Atom x7405C by margins exceeding 430% in all six head-to-head comparisons. The Atom x7405C, a mobile Amston Lake processor, does not win a single benchmark in this matchup, yet its average benchmark score of 6568 places it within 0.6% of the Core i9-10940X’s 6605 average, a statistical tie driven by a different set of workloads that favor the Atom’s efficiency-oriented design.

Head-to-Head Benchmarks

The most striking result is the sheer scale of the Core i9-10940X’s victory in multi-threaded rendering workloads. In Cinebench R15 multi-core, the Core i9-10940X scores 2370 versus the Atom x7405C’s 446, a delta of 431.4%. This advantage narrows only slightly in Cinebench R20 multi-core, where the Core i9-10940X posts 9878 against 1862, a 430.5% lead, and in Cinebench R23 multi-core, the scores are 23520 and 4435, respectively, a 430.3% delta. These results indicate that the Core i9-10940X’s 14 physical cores and 28 threads provide roughly 5.3 times the multi-threaded throughput of the Atom’s 4 cores and 4 threads, a ratio that holds consistently across all three Cinebench versions.

Single-threaded performance tells a similar story, though the margins are slightly larger. In Cinebench R15 single-core, the Core i9-10940X scores 334 versus the Atom’s 62, a 438.7% delta. Cinebench R20 single-core shows 1394 against 262, a 432.1% lead, and Cinebench R23 single-core records 3320 versus 626, a 430.4% delta. The consistency of these deltas, all clustered between 430% and 439%, suggests that the performance gap is not workload-dependent but rather reflects a fundamental architectural and clock-speed disparity. The Core i9-10940X’s base clock of 3.30 GHz and boost clock of 4.80 GHz dwarf the Atom’s 1.70 GHz base and 3.40 GHz boost, and the Core i9’s larger per-core L1 cache of 64 KB and per-core L2 of 1 MB (versus the Atom’s 96 KB L1 and 2 MB shared L2) do not compensate for the clock and core-count differences.

It is worth noting that the Atom x7405C has benchmark results outside the head-to-head set, including PassMark tests where it scores 56317 in data compression, 4004 in data encryption, and 9063 in floating-point math. However, these tests are not shared with the Core i9-10940X, so they cannot be compared directly. The data that is comparable unequivocally favors the Core i9-10940X, with the six head-to-head wins going to the desktop part and zero to the Atom.

The Verdict

From the data, the choice is unambiguous for any user prioritizing raw compute performance. The Core i9-10940X is the only option for multi-threaded rendering, content creation, or any workload that scales with core count. Its Cinebench R23 multi-core score of 23520 is 5.3 times the Atom’s 4435, and its single-core score of 3320 is likewise 5.3 times the Atom’s 626. A user running Cinebench R20 would see the Core i9 finish the multi-core test in roughly one-fifth the time of the Atom, assuming linear scaling, which is a decisive advantage for professional workloads.

However, the average benchmark score of both parts is nearly identical, 6605 for the Core i9-10940X and 6568 for the Atom x7405C, which indicates that the Atom’s PassMark results (which include integer math at 14669, multithread at 5218, and single-thread at 1675) are strong enough in their respective categories to offset the Cinebench deficits. This suggests that the Atom x7405C may be competitive in specific embedded or mobile tasks that resemble those PassMark workloads, such as integer-heavy data processing or encryption, where its 12-watt TDP and 38.4 GB/s memory bandwidth could be more relevant than raw core counts. The Core i9-10940X, with a 165-watt TDP, is not designed for power-constrained environments, and its 62nd percentile ranking among all CPUs is matched by the Atom’s 62nd percentile, meaning both parts sit at the same overall performance level when averaged across their respective benchmark suites.

For a user who must run Cinebench-class workloads, the Core i9-10940X is the only rational pick. For a user in a mobile or embedded context where the PassMark suite is more representative, the Atom x7405C’s lower TDP and comparable average score make it a defensible choice, though it cannot match the Core i9 in any shared test. The data does not support any scenario where the Atom outperforms the Core i9 in a direct comparison.

Architecture Differences

The two processors are built on fundamentally different architectures and process nodes. The Core i9-10940X uses the Cascade Lake architecture, specifically Cascade Lake-X, on a 14 nm process node from Intel’s own foundry. It is a 10th-generation Core i9 part from the X-Series, designed for the Intel Socket 2066 platform. The Atom x7405C, in contrast, uses the Amston Lake architecture with the Gracemont microarchitecture, built on a 10 nm process node, also from Intel’s foundry. The Atom is a 4th-generation part labeled simply as Atom, and it uses the Intel BGA 1264 socket.

Cache hierarchies differ substantially. The Core i9-10940X allocates 64 KB of L1 cache per core and 1 MB of L2 cache per core, with a shared 19.25 MB L3 cache. The Atom x7405C has 96 KB of L1 per core and 2 MB of shared L2, with 6 MB of shared L3. The Core i9’s per-core L2 design is a hallmark of high-performance desktop parts, allowing each core independent fast access, whereas the Atom’s shared L2 is typical of efficiency-focused designs. The Core i9 also supports DDR4 memory in a quad-channel configuration, while the Atom supports both DDR4 and DDR5 but only in a single-channel configuration, with a stated memory bandwidth of 38.4 GB/s. The Core i9 has no listed memory bandwidth figure in the data.

The Atom x7405C includes integrated graphics marked as “N/A” in the data, while the Core i9-10940X has no integrated graphics field listed. PCIe support also differs: the Core i9 uses PCIe Gen 3, and the Atom uses PCIe Gen 3 with 9 lanes (CPU only). The Core i9 has an unlocked multiplier, indicating overclocking capability, while the Atom’s multiplier is locked. The Atom has a part number of SRNEM, whereas the Core i9 has no part number listed in the data.

Specification Differences

The specification table highlights the core count and clock speed disparity. The Core i9-10940X has 14 cores and 28 threads, base clock of 3.30 GHz, and boost clock of 4.80 GHz, with a TDP of 165 watts. The Atom x7405C has 4 cores and 4 threads, base clock of 1.70 GHz, boost clock of 3.40 GHz, and a TDP of 12 watts. The Core i9’s boost clock is 1.4 GHz higher, and its base clock is 1.6 GHz higher, which directly explains the single-threaded benchmark results.

The memory bus is another clear differentiator: the Core i9 uses quad-channel DDR4, while the Atom uses single-channel DDR4 or DDR5 with a bandwidth of 38.4 GB/s. The Core i9 supports ECC memory as false, and the Atom also lists ECC memory as false. The Core i9 uses the Intel Socket 2066, while the Atom uses Intel BGA 1264. The market segment for the Core i9 is Desktop, and for the Atom it is Mobile. The release dates differ by over four years: the Core i9 was released on 2019-10-18, and the Atom on 2024-04-07. The Atom has a launch MSRP of $57, which is the only pricing information available; the Core i9 has no launch MSRP listed.

The Core i9 has an unlocked multiplier, while the Atom does not. The Atom’s process node is 10 nm versus the Core i9’s 14 nm, indicating a newer manufacturing process for the Atom. The Core i9’s generation is listed as “Core i9 (X-Series 10th Gen),” and the Atom’s generation is “Atom (Gracemont).” No transistor counts or die sizes are listed for either part.

FAQ

Q: Which processor is faster in Cinebench R23 multi-core?

A: The Intel Core i9-10940X scores 23520 in Cinebench R23 multi-core, compared to the Intel Atom x7405C’s 4435, a 430.3% delta favoring the Core i9.

Q: What is the average benchmark score difference between the two?

A: The Core i9-10940X has an average benchmark score of 6605, and the Atom x7405C has an average of 6568, a difference of 0.6% in favor of the Core i9.

Q: Does the Atom x7405C win any head-to-head benchmark against the Core i9-10940X?

A: No. The head-to-head data shows the Core i9-10940X winning all six shared tests, with winsA equal to 6 and winsB equal to 0.

Q: What are the core and thread counts for each processor?

A: The Core i9-10940X has 14 cores and 28 threads, while the Atom x7405C has 4 cores and 4 threads.

Q: What is the TDP of each processor?

A: The Core i9-10940X has a TDP of 165 watts, and the Atom x7405C has a TDP of 12 watts.

Q: Which processor supports DDR5 memory?

A: The Atom x7405C supports both DDR4 and DDR5 memory, while the Core i9-10940X supports only DDR4.