AMD Ryzen 7 7840U vs AMD Ryzen 9 6900HS Comparison

The AMD Ryzen 7 7840U and AMD Ryzen 9 6900HS are both 8-core, 16-thread mobile processors, but the benchmark data reveals two very distinct performance profiles. The 7840U, built on the newer Zen 4 architecture, wins 13 of the 23 head-to-head comparisons, while the 6900HS, with its higher 35W TDP and Zen 3+ architecture, claims 10 wins. This split is not arbitrary; it reflects a fundamental divide between single-thread efficiency and raw multi-threaded throughput.

Head-to-Head Benchmarks

The most striking result in the entire dataset is the 7840U’s performance in the PassMark find prime numbers test. The 7840U scores 80, while the 6900HS scores 58, giving the 7840U a commanding 37.9% lead. This is the largest margin of victory for either processor in any test. It signals that the Zen 4 core handles integer-heavy, branch-predictable workloads far more efficiently than the Zen 3+ core.

The 7840U’s advantage extends to other compute-heavy tasks. In Geekbench single-core, the 7840U scores 2077 against the 6900HS’s 1733, a 19.8% lead. The 3DMark single-thread test shows a smaller but still positive result, with 932 versus 915, a 1.9% edge. Cinebench R23 single-core also favors the 7840U, at 1677.5 versus 1554, a 7.9% margin. The 7840U takes the PassMark single-thread test by a 10.1% margin (3565 vs 3237) and PassMark physics by 20.7% (1256 vs 1041). It also wins PassMark floating-point math (51767 vs 48239, +7.3%), integer math (90852 vs 86449, +5.1%), and random string sorting (33757 vs 30528, +10.6%).

The 6900HS, however, dominates the 3DMark multi-threaded suite. In 3DMark 16-thread, it scores 6963 against the 7840U’s 5427, a 22.1% lead. The 8-thread test shows a 21.4% advantage (5830 vs 4583), and the max-thread test shows a 22.3% lead (6955 vs 5402). Even the 4-thread test favors the 6900HS by 11.6% (3427 vs 3029). The 6900HS also wins Cinebench R15 multi-core (2161 vs 1990, +7.9%) and Cinebench R23 multi-core (13445 vs 12719, +5.4%). Geekbench multi-core goes to the 6900HS as well, with 9451 versus 8766, a 7.2% margin.

The remaining wins for the 6900HS are narrower. In PassMark data compression, it scores 292842 versus 288604, a 1.4% edge. Data encryption is a 3.3% win (18303 vs 17691). The 2-thread 3DMark test is a near tie, with the 6900HS winning by just 1.8% (1761 vs 1729). The overall picture is clear: the 7840U wins every single-thread test, while the 6900HS wins every 3DMark multi-threaded test and both Cinebench multi-core tests.

Architecture Differences

The two processors are built on different architectures and processes. The 7840U uses the Zen 4 architecture, codenamed Phoenix, fabricated on a 4 nm TSMC process. The 6900HS uses Zen 3+, codenamed Rembrandt, on a 6 nm TSMC process. This process node difference is a primary driver of the 7840U’s single-thread advantage. The newer node allows for higher clock speeds at comparable power, which is reflected in the boost clocks: the 7840U boosts to 5.10 GHz, while the 6900HS boosts to 4.90 GHz. Both have the same 3.30 GHz base clock.

The L2 cache configuration differs significantly. The 7840U has 1 MB of L2 cache per core, while the 6900HS has 512 KB per core. Both share 16 MB of L3 cache. The larger L2 cache on the 7840U likely contributes to its lead in latency-sensitive tasks like the prime number test and integer math. The 7840U also has a larger die at 178 mm², while the 6900HS is 208 mm², despite the 7840U having more transistors (25,000 million for the 7840U, versus no listed figure for the 6900HS).

Memory bandwidth also differs. The 7840U supports 89.6 GB/s, while the 6900HS supports 76.8 GB/s. Both support DDR5 memory on a dual-channel bus. The sockets are different as well: the 7840U uses AMD Socket FP8, while the 6900HS uses AMD Socket FP7. The integrated graphics differ too, with the 7840U featuring the Radeon 780M and the 6900HS featuring the Radeon 680M. The 7840U supports ECC memory, while the 6900HS does not. The TDP is another key split: the 7840U is rated at 28W, while the 6900HS is rated at 35W.

Where Each One Wins

The data suggests a clear workload-based separation. The 7840U is the winner for any task that depends on single-threaded performance. This includes the Geekbench single-core test, where it leads by 19.8%, and the Cinebench R23 single-core test, where it leads by 7.9%. Its 37.9% lead in the PassMark prime number test suggests it is particularly well-suited for scientific or cryptographic workloads that rely on quick integer calculations. The 20.7% lead in PassMark physics also points to an advantage in simulation and physics-based applications that are not fully multi-threaded.

The 6900HS, on the other hand, is the winner for heavily multi-threaded, sustained workloads. The 3DMark 16-thread and max-thread tests, where it leads by over 22%, indicate it can maintain high throughput when all cores are active. The Cinebench R23 multi-core win, at 13445 versus 12719, is a 5.4% margin that reflects a real-world advantage in video rendering and 3D modeling. The Geekbench multi-core result, a 7.2% lead, reinforces this. The 6900HS’s higher 35W TDP likely allows it to sustain higher all-core clocks for longer periods than the 28W 7840U.

The 7840U still wins PassMark multi-thread by 7% (24782 vs 23152), which is interesting because it indicates that the 7840U’s efficiency can overcome the 6900HS’s raw throughput in some multi-threaded tests. The PassMark suite appears to weight single-thread and mixed workloads more heavily than the pure multi-threaded 3DMark tests. The 7840U also wins PassMark extended instructions by 2.1%, suggesting a slight edge in AVX-related workloads.

The Verdict

Based strictly on the benchmark data, the choice comes down to the primary use case. The AMD Ryzen 7 7840U is the superior processor for users who prioritize single-threaded performance and efficiency. It wins every single-thread test and offers a massive lead in the prime number and physics tests. Its 19.8% advantage in Geekbench single-core is the largest margin in any mainstream benchmark. The 7840U is the better choice for general productivity, office work, and applications that are not fully optimized for multi-threading.

The AMD Ryzen 9 6900HS is the better choice for users running heavily multi-threaded, sustained workloads. Its 22.1% lead in 3DMark 16-thread and 22.3% lead in max-thread tests are decisive. For video editing, 3D rendering, or any task that can utilize all 16 threads, the 6900HS will deliver faster completion times. The Cinebench R23 multi-core score of 13445 versus 12719 confirms this advantage in a widely used rendering benchmark.

The 7840U’s wins in PassMark multi-thread and physics, however, suggest that its architectural efficiency can sometimes overcome the 6900HS’s higher TDP. The 7840U is not a slouch in multi-threaded tasks; it just trails in the most extreme all-core scenarios. The 6900HS, conversely, is not weak in single-threaded tasks, but it loses every such test. The verdict is a split decision: pick the 7840U for a balanced, efficient system with strong single-thread performance, or pick the 6900HS for a system that will spend most of its time under heavy multi-core load.

FAQ

Q: Which processor has a higher boost clock?

A: The AMD Ryzen 7 7840U has a boost clock of 5.10 GHz, while the AMD Ryzen 9 6900HS has a boost clock of 4.90 GHz.

Q: How much larger is the L2 cache on the 7840U?

A: The 7840U has 1 MB of L2 cache per core, while the 6900HS has 512 KB per core.

Q: What is the biggest single benchmark win for the 7840U?

A: The 7840U wins the PassMark find prime numbers test by 37.9%, scoring 80 versus the 6900HS’s 58.

Q: What is the biggest single benchmark win for the 6900HS?

A: The 6900HS wins the 3DMark max-thread test by 22.3%, scoring 6955 versus the 7840U’s 5402.

Q: Do both processors support DDR5 memory?

A: Yes, both the 7840U and the 6900HS support DDR5 memory on a dual-channel bus.

Q: Which processor has a higher TDP?

A: The AMD Ryzen 9 6900HS has a higher TDP at 35W, while the AMD Ryzen 7 7840U is rated at 28W.

Specification Differences

| Specification | AMD Ryzen 7 7840U | AMD Ryzen 9 6900HS |

| :--- | :--- | :--- |

| Series | 7000 series | 6000 series |

| Architecture | Zen 4 | Zen 3+ |

| Codename | Phoenix | Rembrandt |

| Process Node | 4 nm | 6 nm |

| Boost Clock | 5.10 | 4.90 |

| TDP | 28 | 35 |

| Socket | AMD Socket FP8 | AMD Socket FP7 |

| L2 Cache | 1 MB (per core) | 512 KB (per core) |

| Transistors | 25,000 million | Not listed |

| Die Size | 178 mm² | 208 mm² |

| Memory Bandwidth | 89.6 GB/s | 76.8 GB/s |

| ECC Memory | True | False |

| Integrated Graphics | Radeon 780M | Radeon 680M |