AMD Ryzen 5 7645HX vs AMD Ryzen 7 8840HS Comparison

The AMD Ryzen 5 7645HX and AMD Ryzen 7 8840HS are both Zen 4 mobile parts, but they target very different use cases. The 7645HX is a 45 W Dragon Range chip built for high-performance gaming laptops, while the 8840HS is a 28 W Hawk Point chip designed for thin-and-light ultrabooks. Benchmark data shows the two are nearly inseparable in average score—33668 versus 33667—yet their individual test results reveal starkly different strengths. The 7645HX wins 14 of 17 head-to-head tests, often by double-digit margins, while the 8840HS counters with wins in floating-point math, integer math, and random string sorting.

FAQ

Q: Which CPU has the higher average benchmark score?

A: The AMD Ryzen 5 7645HX edges out the Ryzen 7 8840HS by a single point, 33668 to 33667. Both sit at the 84th percentile of all CPUs.

Q: How do the core counts differ?

A: The Ryzen 7 8840HS has 8 cores and 16 threads, while the Ryzen 5 7645HX has 6 cores and 12 threads. Despite having fewer cores, the 7645HX wins most multi-threaded tests.

Q: Which chip has the larger L3 cache?

A: The Ryzen 5 7645HX has 32 MB of shared L3 cache, double the 16 MB found on the Ryzen 7 8840HS. Both have 64 KB L1 and 1 MB L2 per core.

Q: What is the TDP difference?

A: The Ryzen 5 7645HX is rated at 45 W, while the Ryzen 7 8840HS is rated at 28 W. This makes the 8840HS better suited for power-constrained laptops.

Q: Which CPU has the faster base clock?

A: The Ryzen 5 7645HX runs at 4.00 GHz base versus 3.30 GHz on the Ryzen 7 8840HS. The 8840HS has a slightly higher boost clock at 5.10 GHz versus 5.00 GHz.

Q: What are the integrated graphics options?

A: The Ryzen 5 7645HX comes with Radeon 610M graphics, while the Ryzen 7 8840HS features the more capable Radeon 780M. Neither CPU has a dedicated GPU listed in the data.

Architecture Differences

The two CPUs share the Zen 4 architecture but are built on different processes and dies. The Ryzen 5 7645HX uses TSMC's 5 nm node with 6,570 million transistors on a 71 mm² die, codenamed Dragon Range. The Ryzen 7 8840HS uses TSMC's 4 nm node with 25,000 million transistors on a 178 mm² die, codenamed Hawk Point. That is a massive transistor count difference—nearly four times more on the 8840HS—but the 7645HX compensates with higher clocks and a larger L3 cache.

Memory support is DDR5 dual-channel for both, but the 8840HS offers higher bandwidth at 89.6 GB/s versus 83.2 GB/s. The 7645HX supports ECC memory, while the 8840HS does not. PCIe capability differs significantly: the 7645HX provides Gen 5 with 28 lanes (CPU only), while the 8840HS is limited to Gen 4 with 20 lanes. The sockets are different too—AMD Socket FL1 for the 7645HX and AMD Socket FP8 for the 8840HS.

The 7645HX has a 32 MB shared L3 cache, which is double the 16 MB on the 8840HS. Both have 64 KB L1 and 1 MB L2 per core. The 8840HS has more cores and threads (8/16 versus 6/12) but compensates with a lower base clock of 3.30 GHz versus 4.00 GHz. The 8840HS boosts slightly higher at 5.10 GHz versus 5.00 GHz. The 7645HX is a 45 W part, while the 8840HS sips at 28 W. Neither has an unlocked multiplier.

Head-to-Head Benchmarks

The Ryzen 5 7645HX dominates the synthetic benchmarks, posting wins in 14 of 17 tests. The largest margin comes in PassMark find prime numbers, where it scores 178 versus 79—a 125.3% advantage. Geekbench single-core shows a 39.9% lead (2657 versus 1899), and PassMark physics shows a 30.3% lead (1497 versus 1149). In Cinebench R15 multicore, the 7645HX scores 2276 versus 2045, an 11.3% win. Cinebench R23 multicore favors it by 6.9% (13985 versus 13082). Single-core Cinebench R15 sees a 7% win (289 versus 270), and R23 single-core is 4.1% ahead (1809 versus 1737). Geekbench multicore shows a 14.7% lead (11586 versus 10104). PassMark multithread is 5.9% higher (26476 versus 24990), and PassMark single-thread is 7.7% higher (3907 versus 3626). Data compression goes to the 7645HX by 3.2% (302256 versus 292888), encryption by 1.4% (17900 versus 17650), and extended instructions by 10.9% (22969 versus 20714).

The Ryzen 7 8840HS wins three tests. Its biggest margin is in PassMark integer math, scoring 90382 versus 77432—a 14.3% lead. Floating-point math goes to the 8840HS by 7.2% (52582 versus 48798). Random string sorting favors it by 3% (35517 versus 34434). These wins show the 8840HS excels in pure arithmetic workloads, likely due to its extra two cores, but loses almost everywhere else.

The Verdict

Pick the AMD Ryzen 5 7645HX if you prioritize raw CPU performance in most benchmarks. It is faster in Cinebench R15 and R23 multicore, Geekbench multicore and single-core, PassMark multithread, physics, data compression, encryption, extended instructions, find prime numbers, and single-thread tests. The 11.3% Cinebench R15 multicore win and 14.7% Geekbench multicore win are decisive for CPU-heavy workloads. The 39.9% Geekbench single-core lead is the single largest advantage in any common test.

Pick the AMD Ryzen 7 8840HS if you need better power efficiency and integrated graphics. It runs at 28 W versus 45 W, making it far more suitable for thin laptops. The Radeon 780M is a stronger iGPU than the Radeon 610M, though the data does not quantify graphics performance. Its wins in integer math and floating-point math suggest it handles arithmetic-heavy tasks better, but those are niche wins. The 8840HS also offers higher memory bandwidth at 89.6 GB/s versus 83.2 GB/s.

The average benchmark scores are effectively tied at 33668 versus 33667, and both sit at the 84th percentile. But the distribution of wins is lopsided. The 7645HX is the faster processor in almost every measured scenario, despite having fewer cores and a much smaller transistor budget. The 8840HS is the better choice only if the 28 W TDP and superior iGPU matter more than multicore speed.

Specification Differences

| Specification | AMD Ryzen 5 7645HX | AMD Ryzen 7 8840HS |

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

| Cores | 6 | 8 |

| Threads | 12 | 16 |

| Base Clock | 4.00 GHz | 3.30 GHz |

| Boost Clock | 5.00 GHz | 5.10 GHz |

| TDP | 45 W | 28 W |

| Socket | AMD Socket FL1 | AMD Socket FP8 |

| Codename | Dragon Range | Hawk Point |

| Process Node | 5 nm | 4 nm |

| Transistors | 6,570 million | 25,000 million |

| Die Size | 71 mm² | 178 mm² |

| L3 Cache | 32 MB (shared) | 16 MB (shared) |

| Memory Bandwidth | 83.2 GB/s | 89.6 GB/s |

| ECC Memory | Yes | No |

| PCIe | Gen 5, 28 Lanes (CPU only) | Gen 4, 20 Lanes (CPU only) |

| Integrated Graphics | Radeon 610M | Radeon 780M |

| Part Number | 100-000000872 | 100-000001372 (FP7r2), 100-000001379 (FP7), 100-000001357 (FP8) |

Where Each One Wins

The Ryzen 5 7645HX wins in all Cinebench tests, both Geekbench tests, PassMark multithread, physics, data compression, encryption, extended instructions, find prime numbers, and single-thread. That covers rendering, general productivity, compression, and single-threaded applications. The 125.3% lead in find prime numbers is enormous, and the 39.9% Geekbench single-core lead means everyday responsive tasks will feel snappier. The 45 W TDP and larger L3 cache likely explain why it outperforms despite fewer cores.

The Ryzen 7 8840HS wins in PassMark integer math, floating-point math, and random string sorting. These are specific arithmetic and sorting workloads where the extra two cores help. The 14.3% integer math lead is notable for math-heavy applications. The 28 W TDP makes it the clear choice for battery-conscious laptops. The Radeon 780M iGPU is a significant upgrade over the 610M, and the 4 nm process with 25,000 million transistors suggests better efficiency per watt. For a thin-and-light machine that mostly runs office tasks and light gaming, the 8840HS is the practical pick. For any workload that stresses the CPU, the 7645HX is the better performer.