AMD Ryzen 5 PRO 8640HS vs AMD Ryzen 7 PRO 6850U Comparison

The AMD Ryzen 5 PRO 8640HS and AMD Ryzen 7 PRO 6850U are both mobile processors aimed at professional laptops, but they represent two very different design philosophies from AMD. The 8640HS is a newer, higher-power part from the 8000 series, while the 6850U is an efficiency-focused chip from the 6000 series. Benchmark data reveals a clear split: the Ryzen 5 PRO 8640HS dominates in raw compute and single-threaded tasks, while the Ryzen 7 PRO 6850U holds its own in specific memory and integer workloads. Out of 15 head-to-head comparisons, the 8640HS wins 12, with the 6850U taking only 3.

Head-to-Head Benchmarks

The most striking result in the entire dataset is the Cinebench R23 multi-core test. Here, the AMD Ryzen 5 PRO 8640HS scores 18104, while the AMD Ryzen 7 PRO 6850U scores 10047. This translates to a massive 80.2% lead for the 8640HS, making it the single largest performance gap between the two processors. Similarly, in Cinebench R23 single-core, the 8640HS posts 2555 against the 6850U’s 1501, a 70.2% advantage. These results suggest that the 8640HS is in a completely different performance tier for sustained and burst workloads.

The single-core advantage is consistent across other tests. In Cinebench R15 single-core, the 8640HS leads with 257 points versus 238 points, an 8% delta. The PassMark single-thread test shows a 10.1% lead for the 8640HS (3561 vs 3234). Even in older Cinebench R15 multi-core, the 8640HS wins by a smaller margin of 3.3% (1824 vs 1766), showing that while the 6850U can compete in legacy multi-threaded tests, it falls far behind in modern rendering workloads.

The 8640HS also wins decisively in several PassMark sub-tests. In extended instructions, it scores 18507 versus 16054, a 15.3% win. The find prime numbers test shows a 26.8% advantage (71 vs 56). Random string sorting goes to the 8640HS by 13.2% (30235 vs 26716). The physics test is closer, with the 8640HS winning 1043 to 989, a 5.5% margin. The multithread test also favors the 8640HS, scoring 21465 against 20716, a 3.6% win. Even floating-point math, which is nearly identical, goes to the 8640HS at 43019 versus 42999, a negligible 0% delta.

However, the AMD Ryzen 7 PRO 6850U is not without its victories. Its most significant win comes in PassMark integer math, where it scores 79479 against the 8640HS’s 69839, a 12.1% advantage. This is a substantial reversal, indicating the 6850U’s higher core count (8 vs 6) helps in pure integer arithmetic. The 6850U also wins data encryption with a score of 15995 versus 14962, a 6.5% lead. Finally, it edges out the 8640HS in data compression, scoring 249799 against 246446, a slim 1.3% margin. These wins suggest the 6850U excels in specific security and compression workloads, despite losing the overall benchmark war.

Architecture Differences

The two processors are built on fundamentally different architectures. The AMD Ryzen 5 PRO 8640HS uses the Zen 4 architecture under the codename "Hawk Point," while the AMD Ryzen 7 PRO 6850U relies on the older Zen 3+ architecture, codenamed "Rembrandt." This generational gap is the primary driver of the performance differences. The 8640HS is manufactured on a 4 nm process node at TSMC, whereas the 6850U uses a 6 nm process node, also from TSMC. The smaller node gives the 8640HS a transistor density advantage, though the 6850U has a larger die size at 208 mm² compared to the 8640HS’s 178 mm².

Core and thread counts differ significantly. The 8640HS features 6 cores and 12 threads, while the 6850U has 8 cores and 16 threads. This explains the 6850U’s wins in integer math, as it simply has more physical cores to throw at parallel integer tasks. Cache layouts also diverge. Both share a 64 KB L1 cache per core and 16 MB of shared L3 cache. However, the L2 cache differs: the 8640HS has 1 MB per core, while the 6850U has 512 KB per core. This larger L2 cache on the 8640HS likely contributes to its superior single-threaded performance.

The integrated graphics are another major difference. The 8640HS ships with a Radeon 760M, while the 6850U has a Radeon 680M. While neither is benchmarked in this dataset, the newer Radeon 760M on the 8640HS suggests a more modern GPU architecture. Memory support is also a point of differentiation. Both support DDR5 and dual-channel memory, but the 8640HS offers a higher memory bandwidth of 89.6 GB/s versus the 6850U’s 76.8 GB/s. Additionally, the 8640HS supports ECC memory, while the 6850U does not, making the 8640HS more suitable for error-sensitive professional workloads.

Where Each One Wins

The AMD Ryzen 5 PRO 8640HS is the clear winner for compute-heavy professional tasks. Its 80.2% lead in Cinebench R23 multi-core and 70.2% lead in single-core make it the go-to choice for video rendering, 3D modeling, and software compilation. The 26.8% advantage in prime number finding and 15.3% lead in extended instructions further cement its status for scientific computing and complex mathematical simulations. Its 10.1% single-thread lead is also critical for legacy applications that rely on one core. For users who need maximum performance in a thin-and-light laptop, the 8640HS is the superior part, despite having fewer cores.

The AMD Ryzen 7 PRO 6850U wins where its additional cores and lower power draw matter. Its 12.1% victory in integer math suggests it is better suited for database operations, financial modeling, and certain types of encryption algorithms. The 6.5% lead in data encryption is notable for security-focused tasks like VPN processing or disk encryption. The slim 1.3% win in data compression indicates it holds a slight edge in archiving and file management workloads. Furthermore, its 15W TDP (versus 28W for the 8640HS) makes it the better fit for fanless or ultra-portable designs where battery life is paramount.

In terms of overall benchmark averages, the two are remarkably close. The 8640HS has an average benchmark score of 28478, while the 6850U scores 28379, a difference of just 0.3%. Both processors sit in the 80th percentile of all CPUs, meaning they are statistically equivalent in overall performance. The 8640HS’s nearest rival list includes the 6850U with a deltaPct of 0.3%, confirming that while the 8640HS wins more individual tests, the aggregate performance is nearly identical. This makes the choice between them less about raw power and more about specific workload optimization.

Specification Differences

The core specifications reveal a clear trade-off between power and efficiency. The AMD Ryzen 5 PRO 8640HS has a base clock of 3.50 GHz and a boost clock of 4.90 GHz, while the AMD Ryzen 7 PRO 6850U runs at 2.70 GHz base and 4.70 GHz boost. The 8640HS’s higher clocks, especially the 0.8 GHz base clock advantage, explain its single-thread dominance. The TDP is a stark contrast: the 8640HS draws 28W, nearly double the 6850U’s 15W. This power difference is the primary reason the 6850U is better suited for fanless or low-power designs.

Both processors share the same AMD Socket FP7, making them potentially interchangeable in compatible motherboards, though BIOS support would be required. The 8640HS is from the 8000 series with a release date of 2024-04-15, while the 6850U is from the 6000 series, released on 2022-04-18. The 8640HS uses 25,000 million transistors on its 178 mm² die, while the 6850U’s transistor count is not listed, though its die is larger at 208 mm². Both are active production parts, but their part numbers differ, with the 8640HS listed as 100-000001354(FP7r2) and 100-000001382(FP7), and the 6850U as 100-000000538 and 100-000000550.

Other key differences include ECC memory support (yes for the 8640HS, no for the 6850U) and memory bandwidth (89.6 GB/s vs 76.8 GB/s). Both have PCIe Gen 4 with 20 lanes, and neither has an unlocked multiplier. The 8640HS’s L2 cache is 1 MB per core, double the 6850U’s 512 KB per core. The integrated graphics differ as well, with the 8640HS using a Radeon 760M and the 6850U using a Radeon 680M. Finally, the process node is 4 nm for the 8640HS and 6 nm for the 6850U, reflecting the generational improvement.

FAQ

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

A: The AMD Ryzen 5 PRO 8640HS is significantly faster, scoring 18104 in Cinebench R23 multi-core versus the AMD Ryzen 7 PRO 6850U’s 10047, an 80.2% lead.

Q: Does the AMD Ryzen 7 PRO 6850U have any advantages?

A: Yes, it wins in PassMark integer math (79479 vs 69839), data encryption (15995 vs 14962), and data compression (249799 vs 246446), despite having a lower TDP.

Q: What is the core count difference?

A: The Ryzen 5 PRO 8640HS has 6 cores and 12 threads, while the Ryzen 7 PRO 6850U has 8 cores and 16 threads.

Q: Which processor is more power-efficient?

A: The Ryzen 7 PRO 6850U has a 15W TDP, while the Ryzen 5 PRO 8640HS has a 28W TDP, making the 6850U more suitable for low-power designs.

Q: Do both processors support the same memory?

A: Both support DDR5 and dual-channel memory, but the 8640HS offers 89.6 GB/s bandwidth versus 76.8 GB/s for the 6850U, and only the 8640HS supports ECC memory.

Q: What is the overall performance comparison?

A: Both have an average benchmark score within 0.3% of each other (28478 for the 8640HS vs 28379 for the 6850U), and both sit in the 80th percentile of all CPUs.