AMD Ryzen 7 8840HX vs AMD Ryzen 9 7940HX Comparison

The AMD Ryzen 7 8840HX and AMD Ryzen 9 7940HX are both mobile processors built on the Zen 4 architecture, sharing the same Dragon Range codename, 5 nm TSMC process node, and 55 W TDP. Despite these deep similarities, benchmark data reveals a clear performance hierarchy, with the Ryzen 9 7940HX dominating multi-threaded workloads while the Ryzen 7 8840HX edges ahead in a few specific single-threaded tasks. The data shows a 9-to-4 win split in head-to-head benchmarks favoring the Ryzen 9, but the magnitude and nature of those wins vary significantly across test types.

Head-to-Head Benchmarks

The most substantial victory for the AMD Ryzen 9 7940HX comes in the Cinebench R23 multi-core test, where it scores 29,400 against the Ryzen 7 8840HX's 25,265. This represents a 14.1% advantage, a significant gap that reflects the Ryzen 9's additional four cores and eight threads. The Ryzen 9's lead expands dramatically in PassMark's data compression test, where it posts 693,741 versus 496,427, a 28.4% delta. Similarly, in data encryption, the Ryzen 9 scores 41,974 compared to 29,919, a 28.7% margin. These are not marginal differences; the Ryzen 9 is roughly a third faster in these memory-intensive and parallel workloads.

The pattern continues across other PassMark multi-threaded metrics. Floating point math shows the Ryzen 9 at 121,383 against 86,747, a 28.5% lead. Integer math follows suit with 202,883 versus 146,506, a 27.8% gap. Random string sorting reveals the largest percentage difference in the entire comparison: the Ryzen 9 scores 81,775 against the Ryzen 7's 57,971, a 29.1% deficit for the Ryzen 7. The PassMark multi-thread test itself shows a 21.6% advantage for the Ryzen 9 (53,204 vs 41,732), and even the physics test, which is often less scalable, favors the Ryzen 9 by 4.9% (2,297 vs 2,185). The extended instructions benchmark also goes decisively to the Ryzen 9, with 51,029 versus 36,527, a 28.4% gap.

The AMD Ryzen 7 8840HX, however, is not without its victories. The most notable is in Cinebench R23 single-core, where it scores 1,857 versus the Ryzen 9's 1,807, a 2.8% advantage. This is a meaningful win for a chip with a lower core count, indicating higher per-core efficiency. The Ryzen 7 also wins the PassMark single-thread test, albeit narrowly, with 3,958 against 3,942, a 0.4% margin. In the find prime numbers test, the Ryzen 7 posts a 304 score versus 273, an 11.4% advantage, which is a surprisingly large lead for a workload that typically scales with integer performance and cache. The Ryzen 7's 5.10 GHz boost clock, compared to the Ryzen 9's 5.20 GHz, does not prevent it from taking these single-threaded wins.

Looking at the aggregate data, the Ryzen 9 7940HX holds an average benchmark score of 69,875, while the Ryzen 7 8840HX sits at 71,797. This is a counterintuitive result given the head-to-head losses, but it is explained by the fact that the Ryzen 7's average includes its PassMark single-thread scores and other results where it is competitive. The Ryzen 7 8840HX's nearest rivals include the Intel Core Ultra 7 265KF (deltaPct -0.2%), the Intel Xeon 6517P (deltaPct -0.8%), and the Intel Xeon 6724P (deltaPct -0.8%). The Ryzen 9 7940HX's nearest rivals include the AMD Ryzen 7 9700F (deltaPct -0.2%), Intel Core i7-14700KF (deltaPct -0.4%), and AMD Ryzen 9 7950X (deltaPct 0.5%). Both chips sit at the 94th percentile of all CPUs, indicating they are both high-end parts, but their competitive positioning differs.

The Verdict

The data is unambiguous: the AMD Ryzen 9 7940HX is the superior processor for multi-threaded workloads. Its 14.1% lead in Cinebench R23 multi-core and consistent 27-29% advantages across PassMark's data compression, encryption, floating point, integer math, and string sorting tests make it the clear choice for any application that scales across cores. The 16 cores and 32 threads of the Ryzen 9 provide a substantial parallel processing advantage over the Ryzen 7's 12 cores and 24 threads. Users running video encoding, 3D rendering, scientific simulations, or heavy compilation workloads should select the Ryzen 9 7940HX without hesitation, as the data shows it will complete these tasks roughly a quarter to a third faster.

The AMD Ryzen 7 8840HX is the pick for scenarios where single-threaded performance is the bottleneck. Its 2.8% lead in Cinebench R23 single-core and 11.4% advantage in find prime numbers indicate that it has a slight edge in lightly-threaded tasks like legacy software, certain games, or spreadsheet calculations. The 0.4% margin in PassMark single-thread is negligible, but the Cinebench result is more definitive. However, these wins are narrow, and the Ryzen 9 is only 4.9% behind in the physics test, which is often a proxy for gaming performance. For a mixed workload user, the Ryzen 9's massive multi-threaded advantages far outweigh the Ryzen 7's modest single-threaded wins. The verdict is straightforward: choose the Ryzen 9 7940HX for maximum throughput, choose the Ryzen 7 8840HX only if your primary applications are strictly single-threaded and you want a slight edge there, accepting the large multi-threaded penalty.

Architecture Differences

Both processors are built on the same Zen 4 architecture and share the Dragon Range codename, indicating they are part of the same design family. The process node is identical at 5 nm from TSMC, and both chips have the same transistor count of 13,140 million and a die size of 2x 71 mm². The cache hierarchy is also identical in structure: 64 KB of L1 cache per core, 1 MB of L2 cache per core, and 64 MB of shared L3 cache. Neither processor features 3D V-Cache, and both lack ECC memory support. The integrated graphics are the same Radeon 610M, and memory support is DDR5 with a dual-channel bus and 83.2 GB/s bandwidth. PCIe connectivity is also identical: Gen 5 with 28 lanes (CPU only).

The core difference lies in the core and thread counts. The Ryzen 9 7940HX has 16 cores and 32 threads, while the Ryzen 7 8840HX has 12 cores and 24 threads. This is a four-core, eight-thread difference, which directly explains the multi-threaded benchmark results. The base clocks differ, with the Ryzen 7 at 2.90 GHz and the Ryzen 9 at 2.40 GHz, but the boost clocks are close, with the Ryzen 7 at 5.10 GHz and the Ryzen 9 at 5.20 GHz. The Ryzen 7's higher base clock likely compensates for its fewer cores in single-threaded tasks, but the Ryzen 9's higher boost clock and additional cores dominate in parallel workloads. Both processors have an unlocked multiplier, allowing for overclocking, and use the same AMD Socket FL1. The Ryzen 7 8840HX belongs to the 8000 series, while the Ryzen 9 7940HX is from the 7000 series, but this generation label does not indicate an architectural difference; both are Zen 4.

Specification Differences

The specification table shows a clear divergence in core configuration. The Ryzen 9 7940HX offers 16 cores and 32 threads, a 33% increase in both over the Ryzen 7 8840HX's 12 cores and 24 threads. The base clock is lower on the Ryzen 9 at 2.40 GHz versus 2.90 GHz, but the boost clock is higher at 5.20 GHz versus 5.10 GHz. The TDP is identical at 55 W, as is the socket (AMD Socket FL1), process node (5 nm), foundry (TSMC), and transistor count (13,140 million). The die size is the same at 2x 71 mm². Cache specifications are identical: 64 KB L1 per core, 1 MB L2 per core, and 64 MB L3 shared. Memory support is the same (DDR5, dual-channel, 83.2 GB/s), as is ECC memory support (false), PCIe (Gen 5, 28 lanes), and integrated graphics (Radeon 610M). Both are mobile market segments with active production status and unlocked multipliers. The release dates differ, with the Ryzen 9 7940HX released on 2024-01-16 and the Ryzen 7 8840HX on 2025-04-22, but both lack a launch MSRP.

FAQ

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

A: The AMD Ryzen 9 7940HX is faster, scoring 29,400 versus the Ryzen 7 8840HX's 25,265, a 14.1% advantage.

Q: Does the Ryzen 7 8840HX win any benchmark?

A: Yes, it wins four head-to-head tests: Cinebench R23 single-core (1,857 vs 1,807), PassMark find prime numbers (304 vs 273), and PassMark single-thread (3,958 vs 3,942, listed twice).

Q: What is the core count difference between the two chips?

A: The Ryzen 9 7940HX has 16 cores and 32 threads, while the Ryzen 7 8840HX has 12 cores and 24 threads, a difference of four cores and eight threads.

Q: Are the cache sizes different?

A: No, both processors have identical cache configurations: 64 KB L1 per core, 1 MB L2 per core, and 64 MB shared L3.

Q: Which chip has a higher boost clock?

A: The Ryzen 9 7940HX has a boost clock of 5.20 GHz, while the Ryzen 7 8840HX has a boost clock of 5.10 GHz.

Q: How do these chips compare to their nearest rivals?

A: The Ryzen 7 8840HX's average score of 71,797 is 0.2% below the Intel Core Ultra 7 265KF (71,910) and 0.8% below both the Intel Xeon 6517P (72,350) and Intel Xeon 6724P (72,396). The Ryzen 9 7940HX's average score of 69,875 is 0.2% below the AMD Ryzen 7 9700F (69,996), 0.4% below the Intel Core i7-14700KF (70,163), and 0.5% above the AMD Ryzen 9 7950X (69,515).