AMD Ryzen 5 7645HX vs AMD Ryzen 5 8645HS Comparison

Head-to-Head Benchmarks

The benchmark data tells a remarkably one-sided story: the AMD Ryzen 5 7645HX wins all 15 head-to-head comparisons against the AMD Ryzen 5 8645HS. The margins, however, are far from uniform, ranging from a modest 5.5% single-core advantage to a staggering 137.3% blowout in one specific workload. This is not a case of one chip being slightly faster across the board; the 7645HX demonstrates decisive superiority in certain compute patterns that hints at architectural priorities rather than simple clock speed differences.

Starting with the most widely recognized CPU stress tests, the 7645HX leads the Cinebench R23 multicore run by 5.8%, scoring 13,985 against the 8645HS’s 13,220. The single-core gap in the same suite is nearly identical at 5.5%, with scores of 1,809 and 1,714 respectively. Interestingly, the older Cinebench R15 test shows a wider delta: 8.7% in multicore (2,276 vs 2,094) and 7% in single-core (289 vs 270). This pattern suggests the 7645HX’s advantage grows slightly in less modern rendering workloads, which could indicate better sustained performance under shorter-duration loads.

The PassMark suite reveals where the 7645HX truly separates itself. The most dramatic result is in `find_prime_numbers`, where the 7645HX scores 178 versus just 75 for the 8645HS — a 137.3% advantage. This is an enormous gap that goes far beyond any clock or cache explanation. Prime number finding is heavily dependent on integer arithmetic and branch prediction efficiency, and the data implies the Dragon Range chip has a fundamentally more capable execution pipeline for this type of workload. Similarly, `passmark_physics` shows a 36.7% lead (1,497 vs 1,095), another result that suggests the 7645HX’s design handles physics simulation calculations with far greater efficiency.

Multithreaded throughput is another area of clear dominance. The `passmark_multithread` score favors the 7645HX by 17.2% (26,476 vs 22,586), and `data_encryption` shows a 14.8% edge (17,900 vs 15,588). Interestingly, `data_compression` also favors the 7645HX by 13.9% (302,256 vs 265,483), which is notable because compression workloads often benefit from larger caches — and the 7645HX indeed has double the L3 cache. The `extended_instructions` test also shows a 14.8% lead for the 7645HX (22,969 vs 20,003), indicating better SIMD or AVX-512 style performance.

Even in areas where the 8645HS might have been expected to compete, it falls short. The `floating_point_math` score is 8.8% higher on the 7645HX (48,798 vs 44,833), and `integer_math` shows a 6.6% advantage (77,432 vs 72,640). The `random_string_sorting` test yields an 8.5% gap (34,434 vs 31,748), and the single-thread PassMark test shows a 7% lead (3,907 vs 3,653) — identical to the Cinebench R15 single-core delta. The narrowest margins are in the Cinebench R23 tests, but even there, the 7645HX never dips below 5.5% ahead.

FAQ

Q: Which processor has a higher boost clock?

A: Both the AMD Ryzen 5 7645HX and the AMD Ryzen 5 8645HS have identical boost clocks of 5.00 GHz. The base clock, however, differs: the 8645HS starts at 4.30 GHz while the 7645HX begins at 4.00 GHz.

Q: Are these processors built on the same manufacturing process?

A: No. The 7645HX uses a 5 nm process node, while the 8645HS uses a 4 nm node. Both are fabricated by TSMC, but the smaller node on the 8645HS does not translate into a performance advantage in the benchmark data.

Q: What is the difference in L3 cache capacity?

A: The 7645HX has 32 MB of shared L3 cache, which is twice the 16 MB shared L3 cache found on the 8645HS. This larger cache likely contributes to the 7645HX’s wins in data compression and other cache-sensitive workloads.

Q: Do both processors support ECC memory?

A: No. The 7645HX supports ECC memory, while the 8645HS does not. This could be a deciding factor for users who require error-correcting memory for data integrity in their workflows.

Q: How do their integrated graphics compare?

A: The 8645HS features a Radeon 760M integrated GPU, while the 7645HX has a Radeon 610M. The 8645HS’s graphics solution is the more capable of the two based on the product naming and positioning, though no benchmark data is provided for iGPU performance.

Q: Which processor has a higher average benchmark score?

A: The 7645HX has an average benchmark score of 33,668, placing it in the 84th percentile of all CPUs. The 8645HS averages 33,244, putting it in the 83rd percentile. The difference is small, but the 7645HX edges ahead in this aggregate metric.

Architecture Differences

The two processors share the same Zen 4 architecture and both have 6 cores and 12 threads, but they belong to different chip designs with distinct codenames and target platforms. The 7645HX is part of the Dragon Range family, designed for high-performance mobile gaming laptops, while the 8645HS comes from the Hawk Point family, aimed at thin-and-light performance laptops. The generation labels in the data confirm this split: the 7645HX is listed as "Ryzen 5 (Zen 4 (Dragon Range))" and the 8645HS as "Ryzen 5 (Zen 4 (Hawk Point))".

Manufacturing processes differ meaningfully. The 7645HX uses a 5 nm node at TSMC, while the 8645HS uses a 4 nm node. Interestingly, the transistor counts are wildly different: the 8645HS packs 25,000 million transistors on a 178 mm² die, while the 7645HX has only 6,570 million transistors on a 71 mm² die. This discrepancy suggests the 8645HS integrates far more logic — likely due to the larger iGPU and possibly other system-on-chip components — yet the 7645HX still outperforms it in every CPU benchmark. The die size difference (71 mm² vs 178 mm²) is also notable, indicating the Dragon Range chip is more focused on CPU-only compute density.

Cache hierarchies diverge significantly. Both have 64 KB of L1 per core and 1 MB of L2 per core, but the L3 cache is doubled on the 7645HX: 32 MB shared versus 16 MB shared on the 8645HS. This larger L3 pool is a plausible explanation for the 7645HX’s strong showing in memory-latency-sensitive tasks like data compression and physics simulation. The 7645HX also supports ECC memory, a feature absent on the 8645HS, which may matter for scientific or server-adjacent workloads.

The memory controllers also differ in rated bandwidth. The 8645HS offers 89.6 GB/s of memory bandwidth, while the 7645HX provides 83.2 GB/s. Despite the 8645HS’s higher theoretical bandwidth, the 7645HX wins all compute benchmarks, suggesting that raw bandwidth is not the limiting factor here. PCIe support also differs: the 7645HX has Gen 5 with 28 lanes (CPU only), while the 8645HS has Gen 4 with 20 lanes (CPU only). The newer PCIe standard on the 7645HX could benefit external GPU setups or NVMe storage, though no benchmarks are provided for those scenarios.

Specification Differences

The two chips differ in several key specification fields, starting with the base clock: the 8645HS runs at 4.30 GHz while the 7645HX runs at 4.00 GHz — a 0.30 GHz advantage for the 8645HS. Boost clocks are equal at 5.00 GHz. The socket types are different: the 7645HX uses AMD Socket FL1, while the 8645HS uses AMD Socket FP8. This means they are not drop-in interchangeable without a motherboard change.

Process node and physical characteristics differ as noted: 5 nm vs 4 nm, 6,570 million vs 25,000 million transistors, and 71 mm² vs 178 mm² die size. The L3 cache is 32 MB on the 7645HX versus 16 MB on the 8645HS. Memory bandwidth is higher on the 8645HS at 89.6 GB/s versus 83.2 GB/s. ECC memory support is present only on the 7645HX.

PCIe capabilities are more advanced on the 7645HX (Gen 5, 28 lanes) compared to the 8645HS (Gen 4, 20 lanes). Integrated graphics differ: Radeon 610M on the 7645HX versus Radeon 760M on the 8645HS. The release dates are also distinct: the 7645HX launched on 2023-01-03, while the 8645HS launched on 2023-12-05. Finally, the part numbers differ, with the 8645HS having multiple part number variants for different sockets (FP7r2, FP7, FP8), while the 7645HX has a single part number.

The Verdict

The data is unambiguous: the AMD Ryzen 5 7645HX is the faster processor in every single benchmark recorded, winning all 15 head-to-head comparisons. The average benchmark score difference is small — 33,668 vs 33,244 — but the individual test deltas range from 5.5% to 137.3%, with the 7645HX leading in all cases. The 8645HS’s higher base clock (4.30 GHz vs 4.00 GHz) and higher memory bandwidth (89.6 GB/s vs 83.2 GB/s) do not translate into any performance win. The 7645HX’s larger L3 cache (32 MB vs 16 MB) and different die design (smaller 71 mm² die with far fewer transistors) appear to provide a meaningful compute advantage.

For users who prioritize raw CPU throughput — rendering, physics simulation, encryption, integer math — the 7645HX is the clear choice based on this data. The 8645HS may offer a better integrated GPU (Radeon 760M vs Radeon 610M) and newer process node, but those advantages are not reflected in CPU benchmark scores. The 7645HX also supports ECC memory and PCIe Gen 5, which are tangible feature advantages for specific use cases. The verdict from the benchmarks is simple: if you are choosing between these two for CPU-bound tasks, the 7645HX wins outright.

Where Each One Wins

The AMD Ryzen 5 7645HX wins in every benchmark category included in the data, making it the dominant choice for almost any CPU-intensive workload. Its largest advantages come in prime number finding (137.3% ahead), physics simulation (36.7% ahead), and multithreaded throughput (17.2% ahead). These results suggest the 7645HX excels in scientific computing, engineering simulation, and heavily parallel workloads where its larger L3 cache and Zen 4 Dragon Range design shine. Encryption and extended instruction workloads also favor the 7645HX by 14.8%, making it the better pick for security-focused tasks, data compression (13.9% lead), and any application that leverages advanced SIMD instructions. Even in single-core tasks — where the 8645HS’s higher base clock might have helped — the 7645HX maintains a 5.5% to 7% lead across Cinebench and PassMark tests.

The AMD Ryzen 5 8645HS, despite losing every benchmark, still has reasons to exist based on the specification data. It offers a newer 4 nm process node, which could imply better power efficiency — though no power consumption benchmarks are provided. Its integrated Radeon 760M graphics is likely more capable for light gaming or media playback without a discrete GPU, and it has higher memory bandwidth (89.6 GB/s vs 83.2 GB/s). The 8645HS also has a higher base clock, which might offer better responsiveness in short bursts of single-threaded activity, even if sustained performance falls behind. For users who need a processor with a stronger iGPU for everyday tasks, the 8645HS is the better choice — but for pure CPU compute, the 7645HX is the winner in every measurable way.