Intel Core i9-7940X vs Intel Core i9-9920X Comparison

The Intel Core i9-7940X and the Intel Core i9-9920X are both 14nm Skylake-X processors built for the Intel Socket 2066 platform, sharing identical 165W TDPs, 484 mm² die sizes, and 19.25 MB of shared L3 cache. Despite the newer generation label, the benchmark data consistently favors the 14-core i9-7940X, which wins all eight head-to-head comparisons. The largest margin appears in Geekbench multi-core, where the i9-7940X scores 10516 against the i9-9920X’s 9422, a 11.6% advantage. All other deltas are narrower, but the direction is uniform, making this a rare sweep in the dataset.

Head-to-Head Benchmarks

The multi-core Cinebench results form a tight cluster. In Cinebench R15, the i9-7940X posts 2161 versus the i9-9920X’s 2121, a 1.9% lead. The R20 multicore test shows a similar pattern: 9006 against 8839, again a 1.9% gap. In Cinebench R23 multicore, the i9-7940X reaches 21444 while the i9-9920X scores 21046, with the same 1.9% delta. This consistency across three Cinebench generations indicates the 14-core part holds a steady, if modest, throughput advantage in heavily threaded rendering workloads.

Single-core results are even closer but still favor the i9-7940X. Cinebench R15 single-core yields 305 versus 299, a 2% difference. In R20 single-core, the margin shrinks to 1.9% with scores of 1271 and 1247. The R23 single-core test shows 3027 against 2971, maintaining that 1.9% edge. These results are notable because the i9-9920X has a higher base clock (3.50 GHz versus 3.10 GHz) and a higher boost clock (4.50 GHz versus 4.40 GHz), yet the i9-7940X still edges ahead in single-threaded performance. The data suggests the 14-core chip’s architecture or binning delivers slightly better per-clock efficiency in these tests.

The Geekbench suite provides the most decisive separation. Multi-core Geekbench scores are 10516 for the i9-7940X versus 9422 for the i9-9920X, an 11.6% difference that dwarfs the Cinebench gaps. This large delta likely reflects Geekbench’s sensitivity to the additional two cores and four threads of the i9-7940X. Single-core Geekbench is less dramatic but still favors the i9-7940X: 1445 against 1393, a 3.7% lead. Across all eight benchmarks, the i9-7940X wins with deltas ranging from 1.9% to 11.6%, and the i9-9920X never takes a single victory.

Where Each One Wins

Based strictly on the benchmark wins, the i9-7940X is the clear winner in every category measured. For multi-threaded productivity, the Geekbench multicore result (10516 vs 9422) represents the largest performance gap, making the i9-7940X the stronger choice for workloads that scale with core count, such as video encoding, 3D rendering, and scientific computing. The Cinebench multicore results, while narrower, reinforce this pattern across three different rendering engines.

The i9-9920X does not win any benchmark, so there is no workload in the data where it emerges as the faster processor. However, its higher base and boost clocks (3.50 GHz and 4.50 GHz versus 3.10 GHz and 4.40 GHz) could theoretically benefit lightly threaded tasks, but the single-core benchmarks do not confirm this. In fact, the i9-7940X leads in all single-core tests, so even the clock speed advantage of the i9-9920X fails to translate into a measurable win. For users who might expect the newer generation to bring improvements, the data shows the opposite direction of performance.

The i9-9920X does have a lower launch MSRP of $1189 compared to the i9-7940X’s $1399, but pricing is not a performance metric. In terms of raw benchmark results, the i9-7940X dominates. The nearest rivals for the i9-7940X include the AMD EPYC 7501 (avg score 6128, delta 0.3%) and the AMD Ryzen Threadripper 1950X (avg score 6231, delta -1.4%), placing it in a competitive range. The i9-9920X’s nearest rivals are the AMD EPYC 7451 (avg score 5915, delta 0%) and the Intel Xeon W-2170B (avg score 5985, delta -1.1%), showing it sits slightly lower in overall average benchmark score.

Architecture Differences

Both processors share the same fundamental Skylake-X architecture, 14nm process node, and 484 mm² die size. They also have identical cache hierarchies: 64 KB of L1 per core, 1 MB of L2 per core, and 19.25 MB of shared L3 cache. Memory support is the same as well, with quad-channel DDR4 and 85.3 GB/s of memory bandwidth. PCIe capabilities match at Gen 3 with 44 lanes from the CPU. Neither chip includes integrated graphics, and both have unlocked multipliers for overclocking.

The key architectural difference is the core and thread count. The i9-7940X has 14 cores and 28 threads, while the i9-9920X has 12 cores and 24 threads. This two-core, four-thread advantage for the i9-7940X is the primary driver of its multi-core benchmark wins, particularly in the Geekbench multicore test where the 11.6% delta aligns with the 16.7% increase in core count (from 12 to 14). The i9-9920X compensates with higher clock speeds—3.50 GHz base and 4.50 GHz boost versus 3.10 GHz base and 4.40 GHz boost—but this is insufficient to overcome the core deficit in the tested workloads.

Generation labels differ: the i9-7940X is part of the Core i9 X-Series 7th Gen, while the i9-9920X belongs to the Core i9 X-Series 9th Gen. Release dates also differ, with the i9-7940X launching on 2017-08-31 and the i9-9920X on 2018-10-18. Despite the newer generation, the i9-9920X does not introduce any architectural changes that improve benchmark performance in this dataset. The part numbers differ (SR3RQ for the i9-7940X, SREZ6 for the i9-9920X), but both are end-of-life products. The process node, foundry, and die size are identical, and neither supports ECC memory.

The Verdict

The benchmark data is unambiguous: the Intel Core i9-7940X is the faster processor in every tested workload. For multi-core performance, the i9-7940X leads by 1.9% in all three Cinebench multicore tests and by 11.6% in Geekbench multicore. For single-core performance, the i9-7940X leads by 1.9% to 3.7% across the four single-core tests. The i9-9920X’s higher clock speeds do not yield a single benchmark win, making it the slower choice across the board.

Users prioritizing maximum throughput in rendering, encoding, or any core-scalable application should select the i9-7940X based on its consistent multi-core advantage. The 11.6% Geekbench multicore gap is a significant margin that would translate to tangible time savings in long-running compute tasks. Even in single-threaded scenarios, the i9-7940X’s edge, while small, means there is no scenario in the data where the i9-9920X is preferable on performance grounds.

The i9-9920X offers a lower launch MSRP of $1189 versus $1399 for the i9-7940X, which is a notable consideration for cost-sensitive builds. However, the performance trade-off is steep: 11.6% slower in Geekbench multicore and 1.9% slower in all Cinebench multicore tests. The i9-9920X also holds a lower average benchmark score of 5917 against the i9-7940X’s 6147, and its nearest rivals include the AMD EPYC 7451 at a 0% delta, indicating it is benchmark-equivalent to that server chip. Both processors sit at the 61st percentile among all CPUs, but the i9-7940X achieves this with a higher absolute average score.

For users who must have the fastest available Skylake-X part in this comparison, the i9-7940X is the data-backed choice. The i9-9920X is only advisable if the lower launch MSRP is a deciding factor and the performance deficit is acceptable. The benchmark results show no workload where the i9-9920X outperforms the i9-7940X, so the verdict is straightforward.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Core i9-7940X has 14 cores and 28 threads, while the Intel Core i9-9920X has 12 cores and 24 threads.

Q: What is the largest performance difference between the two?

A: The largest delta is in Geekbench multicore, where the i9-7940X scores 10516 versus the i9-9920X’s 9422, an 11.6% advantage.

Q: Does the i9-9920X win any benchmark?

A: No. The i9-7940X wins all eight head-to-head benchmarks, with deltas ranging from 1.9% to 11.6%.

Q: Are the cache sizes different between the two processors?

A: No. Both have 64 KB of L1 per core, 1 MB of L2 per core, and 19.25 MB of shared L3 cache.

Q: What are the launch MSRP values?

A: The i9-7940X had a launch MSRP of $1399, and the i9-9920X had a launch MSRP of $1189.

Q: How does each processor compare to its nearest rivals?

A: The i9-7940X’s nearest rival is the AMD EPYC 7501 with an average score of 6128 (0.3% delta), while the i9-9920X’s nearest rival is the AMD EPYC 7451 with an average score of 5915 (0% delta).