AMD Ryzen 5 6600H vs AMD Ryzen 5 8640HS Comparison

Head-to-Head Benchmarks

The benchmark data presents a clear split between these two mobile processors. The AMD Ryzen 5 8640HS wins 14 of the 17 recorded head-to-head tests, while the AMD Ryzen 5 6600H takes 3. The margin of victory is not uniform across workloads, and the 6600H's wins are worth examining closely.

The most decisive win for the 8640HS comes in PassMark's find prime numbers test, where it scores 70 against 52 for the 6600H, a 34.6% advantage. This is an outlier in magnitude, but it signals that the newer architecture handles integer-heavy iterative workloads with far greater efficiency. The 8640HS also shows a strong 17.4% lead in Cinebench R23 single-core (1711 versus 1458) and a 14.5% lead in Cinebench R15 single-core (268 versus 234). Single-threaded performance is consistently higher across every recorded test: Geekbench single-core shows 1778 versus 1566, a 13.5% gap, and PassMark single-thread shows 3584 versus 3178, a 12.8% gap.

Multi-threaded benchmarks tell a similar story, though with smaller margins. In Cinebench R23 multi-core, the 8640HS records 11486 against 10322, an 11.3% improvement. Cinebench R15 multi-core shows 1845 versus 1681.5, a 9.7% gain. PassMark multi-thread scores are 19889 versus 18669, a 6.5% edge. PassMark physics (970 versus 891, 8.9%) and floating point math (39725 versus 36796, 8%) also favor the 8640HS. Integer math is closer at 5% (68173 versus 64927), and random string sorting shows a 14.4% advantage (27316 versus 23888) for the 8640HS.

The 6600H does not go down quietly. Its largest win is in PassMark data encryption, scoring 14277 against 13551, a 5.1% advantage. It also edges ahead in data compression, 229879 versus 226544, a 1.5% margin, and in extended instructions, 15903 versus 15855, a 0.3% gap. Geekbench multi-core is effectively a tie: 7461 versus 7444, a 0.2% difference in favor of the 8640HS. These results suggest the 6600H retains a slight lead in certain data-processing and cryptographic workloads, but the overall picture is dominated by the 8640HS.

The Verdict

The data points to the AMD Ryzen 5 8640HS as the stronger processor in the vast majority of scenarios. Its single-core advantage is substantial and consistent, ranging from 12.8% to 17.4% across Cinebench, Geekbench, and PassMark. Multi-core performance is also better, with gains of 6.5% to 11.3% depending on the test. For users who prioritize responsiveness in everyday tasks, compile times, rendering, or any workload that scales across all 6 cores and 12 threads, the 8640HS is the clear pick.

The AMD Ryzen 5 6600H is not without merit. In data encryption, it leads by 5.1%, and in data compression it leads by 1.5%. These are niche but real advantages. Extended instructions are essentially tied. However, the 6600H cannot match the 8640HS in raw compute throughput, and its single-core deficit is too large to ignore.

Both processors sit at the 78th percentile among all CPUs in the database, which means they occupy the same general performance tier. The average benchmark score for the 8640HS is 26106, while the 6600H averages 25550. That is a 2.2% overall gap. The 8640HS is the better buy for general performance, while the 6600H makes sense only if the specific workloads that favor it, encryption and compression, are your primary use case.

Architecture Differences

The two chips come from different generations and use different process nodes. The AMD Ryzen 5 8640HS is built on Zen 4 architecture, codenamed Hawk Point, fabricated on TSMC's 4 nm process. The AMD Ryzen 5 6600H uses Zen 3+ architecture, codenamed Rembrandt, on a 6 nm process. This node shrink is a major factor behind the 8640HS's efficiency and clock speed advantages.

Clock speeds differ notably. The 8640HS has a base clock of 3.50 GHz and a boost clock of 4.90 GHz. The 6600H starts at 3.30 GHz and boosts to 4.50 GHz. The 8640HS is also rated at a 28 W TDP, while the 6600H is rated at 45 W. Despite the lower TDP, the 8640HS delivers higher performance across most tests, which underscores the architectural efficiency gains from Zen 4 and the 4 nm process.

Cache layouts are similar but not identical. Both have 64 KB of L1 per core and 16 MB of shared L3. The L2 cache differs: the 8640HS has 1 MB per core, while the 6600H has 512 KB per core. This gives the 8640HS a total of 6 MB of L2 versus 3 MB for the 6600H, which helps explain its lead in integer math and prime number finding.

The integrated graphics also differ. The 8640HS pairs with a Radeon 760M, while the 6600H uses a Radeon 660M. Memory bandwidth is higher on the 8640HS at 89.6 GB/s compared to 76.8 GB/s for the 6600H, though both support DDR5 in dual-channel mode. The 8640HS uses AMD Socket FP8, while the 6600H uses AMD Socket FP7. Both offer PCIe Gen 4 with 20 CPU lanes, and neither supports ECC memory or an unlocked multiplier.

FAQ

Q: Which processor is faster in single-core performance?

A: The AMD Ryzen 5 8640HS wins every recorded single-core test. It leads by 14.5% in Cinebench R15 single-core (268 versus 234), 17.4% in Cinebench R23 single-core (1711 versus 1458), 13.5% in Geekbench single-core (1778 versus 1566), and 12.8% in PassMark single-thread (3584 versus 3178).

Q: Does the AMD Ryzen 5 6600H win any benchmark at all?

A: Yes. The 6600H wins PassMark data encryption by 5.1% (14277 versus 13551), PassMark data compression by 1.5% (229879 versus 226544), and PassMark extended instructions by 0.3% (15903 versus 15855).

Q: How do their TDP ratings compare?

A: The AMD Ryzen 5 8640HS is rated at 28 W, while the AMD Ryzen 5 6600H is rated at 45 W. The 8640HS delivers higher performance in most tests despite the lower power envelope.

Q: Are both processors based on the same architecture?

A: No. The 8640HS uses Zen 4 (Hawk Point) on a 4 nm TSMC process, while the 6600H uses Zen 3+ (Rembrandt) on a 6 nm TSMC process.

Q: What is the L2 cache difference?

A: The 8640HS has 1 MB of L2 per core, while the 6600H has 512 KB per core. Both share 16 MB of L3 and have 64 KB of L1 per core.

Q: Which processor has better integrated graphics?

A: The 8640HS features a Radeon 760M, while the 6600H features a Radeon 660M. The 8640HS also has higher memory bandwidth at 89.6 GB/s versus 76.8 GB/s.

Where Each One Wins

The AMD Ryzen 5 8640HS is the winner in compute-heavy tasks. Cinebench R23 multi-core (11486 versus 10322) and single-core (1711 versus 1458) both favor it, as do Geekbench multi-core (7461 versus 7444), PassMark multi-thread (19889 versus 18669), PassMark physics (970 versus 891), floating point math (39725 versus 36796), integer math (68173 versus 64927), random string sorting (27316 versus 23888), and find prime numbers (70 versus 52). This makes it the better choice for rendering, video encoding, software compilation, scientific computing, and any workload that stresses the CPU cores.

The AMD Ryzen 5 6600H wins in three specific areas: data encryption (14277 versus 13551), data compression (229879 versus 226544), and extended instructions (15903 versus 15855). These are not trivial workloads. Encryption performance matters for VPNs, secure file transfers, and database encryption. Compression performance matters for archiving, backup tools, and file transfer pipelines. If those are your primary tasks, the 6600H's small but measurable leads are worth noting.

For mixed usage, the 8640HS is the safer recommendation. Its single-core dominance translates directly into snappier application launches, faster browsing, quicker spreadsheet recalculation, and lower latency in games that rely on one fast thread. The 6600H can compete in multi-threaded scenarios where the 8640HS wins by 6.5% to 11.3%, but it cannot close the gap in the workloads where it trails.

Specification Differences

| Field | AMD Ryzen 5 8640HS | AMD Ryzen 5 6600H |

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

| Architecture | Zen 4 (Hawk Point, 8000 series, AMD) | Zen 3+ (Rembrandt, 6000 series, AMD) |

| Process node | 4 nm TSMC, 178 mm² die size, 25,000 million transistors | 6 nm TSMC, 208 mm² die size, transistors not recorded |

| Base clock | 3.50 GHz | 3.30 GHz |

| Boost clock | 4.90 GHz | 4.50 GHz |

| TDP | 28 W | 45 W |

| L1 cache | 64 KB per core | 64 KB per core |

| L2 cache | 1 MB per core | 512 KB per core |

| L3 cache | 16 MB shared | 16 MB shared |

| Memory bandwidth | 89.6 GB/s | 76.8 GB/s |

| Integrated graphics | Radeon 760M | Radeon 660M |

| Socket | AMD Socket FP8 | AMD Socket FP7 |

| PCIe | Gen 4, 20 lanes (CPU only) | Gen 4, 20 lanes (CPU only) |

| ECC support | No | No |

| Unlocked multiplier | No | No |

| Production status | Active | Active |