AMD Ryzen 5 PRO 8640U vs AMD Ryzen 7 5800XT Comparison

The AMD Ryzen 5 PRO 8640U and the AMD Ryzen 7 5800XT occupy opposite ends of the computing spectrum, one a power-sipping mobile part and the other a high-wattage desktop chip. The data shows a clear split: the desktop 5800XT dominates in raw multi-threaded workloads and most single-core Cinebench tests, while the mobile 8640U strikes back in one specific PassMark single-thread metric. The benchmark results reveal that the Ryzen 7 5800XT wins 15 of the 17 head-to-head comparisons, with the Ryzen 5 PRO 8640U taking only 2 wins.

Where Each One Wins

The use-case split is defined by the 5800XT’s overwhelming lead in sustained, thread-heavy work. Across all three Cinebench versions (R15, R20, R23), the 5800XT wins both multi-core and single-core runs by a consistent 16%. This means the 8-core, 16-thread desktop chip is the choice for rendering, video encoding, and any workload that scales with cores and threads. Its PassMark wins are equally broad: data compression, encryption, extended instructions, prime number finding, floating-point math, integer math, multithread, physics, and random string sorting all go to the 5800XT, with deltas ranging from -10.6% to -34.5%.

The 8640U’s sole territory is PassMark single-thread performance, where it scores 3732 versus 3535, a 5.6% advantage. This is a narrow but meaningful win for lightly-threaded responsiveness. The data suggests the 8640U uses its higher 4.90 GHz boost clock and newer Zen 4 architecture to win in short, single-thread bursts, which translates to snappy application launches and smooth UI interaction on a laptop. The 5800XT, despite a 4.80 GHz boost, falls behind here because its Zen 3 architecture and older process likely cap its per-core efficiency. The mobile chip’s 28W TDP also implies it can sustain this performance within a thermal envelope that would be impossible for the 105W desktop part.

The 8640U does not win a single multi-threaded benchmark. This is expected given the 5800XT’s two additional cores and four additional threads. However, the 8640U’s 81st percentile ranking among all CPUs, identical to the 5800XT’s, shows that its 6-core design is no slouch in absolute terms; it just cannot keep pace with a full desktop chip in parallel tasks. For a mobile user, the 8640U offers 80% of the 5800XT’s multi-thread score in Cinebench R23 (19982 vs 23794), which is remarkable for a 28W part.

Architecture Differences

The two chips represent a generational and design philosophy gap. The 8640U is built on TSMC’s 4 nm process with Zen 4 architecture, codenamed Hawk Point, while the 5800XT uses TSMC’s 7 nm process with Zen 3 architecture, codenamed Vermeer. The 8640U packs 25,000 million transistors into a 178 mm² die, whereas the 5800XT uses 4,150 million transistors in a 74 mm² die. This disparity reflects the 8640U’s integrated Radeon 760M graphics, which the 5800XT lacks entirely (its integrated graphics are listed as N/A). The 4 nm node allows the 8640U to achieve a higher 4.90 GHz boost clock on fewer cores while drawing only 28W, compared to the 5800XT’s 105W TDP.

Cache organization differs significantly. Both share 64 KB of L1 per core, but the 8640U has 1 MB of L2 per core versus 512 KB per core on the 5800XT. The 5800XT counters with 32 MB of shared L3, double the 8640U’s 16 MB. This larger L3 pool benefits the 5800XT in data-heavy workloads, likely explaining its 25.9% lead in data compression. Memory support also diverges: the 8640U uses DDR5 with 89.6 GB/s bandwidth, while the 5800XT uses DDR4 at 51.2 GB/s. Both support ECC memory and use Gen 4 PCIe with 20 lanes (CPU only).

The sockets are incompatible: the 8640U uses AMD Socket FP7 (mobile), while the 5800XT uses AMD Socket AM4 (desktop). The 5800XT is multiplier-unlocked, allowing overclocking, while the 8640U is locked. Release dates vary by over three months, with the 8640U launching on 2024-04-15 and the 5800XT on 2024-07-30. The 5800XT has a launch MSRP of $249. The 8640U is marked as an "8000 series" mobile part, while the 5800XT is a "5000 series" desktop chip.

Head-to-Head Benchmarks

The most decisive wins for the 5800XT come in Cinebench R23 multi-core, where it scores 23794 against 19982, a 16% margin. This pattern holds across every Cinebench test: R15 multi-core (2398 vs 2014), R15 single-core (338 vs 284), R20 multi-core (9993 vs 8392), R20 single-core (1410 vs 1184), and R23 single-core (3359 vs 2821). The consistency of the 16% delta across both single and multi-threaded Cinebench tests suggests the 5800XT’s higher base clock (3.80 GHz vs 3.50 GHz) and larger L3 cache give it a fundamental throughput advantage in this renderer.

The widest gap appears in PassMark find prime numbers, where the 5800XT scores 119 versus 78, a 34.5% lead. This workload is highly sensitive to integer execution and cache hierarchy, and the 5800XT’s 32 MB L3 likely reduces memory latency bottlenecks. Data encryption shows a 26.2% gap (21461 vs 15843), and data compression shows a 25.9% gap (352002 vs 260925), both indicating the 5800XT’s larger shared cache is a significant asset. Integer math sees a 20.3% gap (93942 vs 74875), while extended instructions show a 21.2% gap (24270 vs 19130).

The 8640U’s single win is narrow but consistent across the two identical PassMark single-thread entries: 3732 versus 3535, a 5.6% advantage. This is the only test where the newer architecture and higher boost clock overcome the 5800XT’s core count and cache size. Interestingly, the 5800XT wins PassMark physics by only 14.8% (1355 vs 1154), a smaller margin than its integer or floating-point wins, suggesting the 8640U’s Zen 4 cores are comparatively stronger in physics simulation relative to other workloads. Random string sorting shows the smallest overall gap for the 5800XT at 10.6% (35911 vs 32114), implying the 8640U’s memory bandwidth helps in pointer-chasing workloads.

Specification Differences

| Specification | AMD Ryzen 5 PRO 8640U | AMD Ryzen 7 5800XT |

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

| Series | 8000 series | 5000 series |

| Cores | 6 | 8 |

| Threads | 12 | 16 |

| Base Clock | 3.50 GHz | 3.80 GHz |

| Boost Clock | 4.90 GHz | 4.80 GHz |

| TDP | 28W | 105W |

| Socket | AMD Socket FP7 | AMD Socket AM4 |

| Architecture | Zen 4 | Zen 3 |

| Codename | Hawk Point | Vermeer |

| Process Node | 4 nm | 7 nm |

| Transistors | 25,000 million | 4,150 million |

| Die Size | 178 mm² | 74 mm² |

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

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

| Memory Support | DDR5 | DDR4 |

| Memory Bandwidth | 89.6 GB/s | 51.2 GB/s |

| Integrated Graphics | Radeon 760M | N/A |

| Market Segment | Mobile | Desktop |

| Multiplier Unlocked | No | Yes |

| Release Date | 2024-04-15 | 2024-07-30 |

| Launch MSRP | N/A | $249 |

FAQ

Q: Which chip has more cores?

A: The AMD Ryzen 7 5800XT has 8 cores and 16 threads, while the AMD Ryzen 5 PRO 8640U has 6 cores and 12 threads.

Q: Does the Ryzen 5 PRO 8640U have integrated graphics?

A: Yes, it features a Radeon 760M integrated GPU. The Ryzen 7 5800XT has no integrated graphics (N/A).

Q: Which processor has a higher boost clock?

A: The Ryzen 5 PRO 8640U has a boost clock of 4.90 GHz, which is 0.10 GHz higher than the Ryzen 7 5800XT’s 4.80 GHz.

Q: What is the memory bandwidth difference?

A: The Ryzen 5 PRO 8640U supports DDR5 with 89.6 GB/s bandwidth, which is 38.4 GB/s higher than the Ryzen 7 5800XT’s DDR4 at 51.2 GB/s.

Q: Which chip wins in PassMark single-thread performance?

A: The Ryzen 5 PRO 8640U wins with a score of 3732, which is 5.6% higher than the Ryzen 7 5800XT’s 3535.

Q: Is the Ryzen 7 5800XT overclockable?

A: Yes, the multiplier is unlocked. The Ryzen 5 PRO 8640U has a locked multiplier.

The Verdict

The data points to a clear recommendation based on use case. For desktop builders prioritizing multi-threaded performance, the Ryzen 7 5800XT is the definitive choice. It wins every Cinebench test by 16%, and its PassMark leads range from 10.6% to 34.5%. The 8-core, 16-thread configuration, combined with 32 MB of L3 cache, makes it superior for rendering, compression, encryption, and any parallel workload. Its launch MSRP is $249, and it is multiplier-unlocked for enthusiasts.

For mobile users or those needing a low-power solution, the Ryzen 5 PRO 8640U is the only viable option, given its 28W TDP and FP7 socket. Its 5.6% win in PassMark single-thread indicates faster per-core responsiveness, and its 4.90 GHz boost clock on a 4 nm process shows architectural efficiency. The integrated Radeon 760M eliminates the need for a discrete GPU in basic systems. The 8640U’s 81st percentile ranking, equal to the 5800XT, confirms it delivers comparable absolute performance despite having fewer cores and a fraction of the power budget.

The verdict is not about which is "better" overall, but which fits the environment. The 5800XT is a desktop workhorse that dominates in threaded tasks. The 8640U is a mobile marvel that wins in single-threaded snappiness and offers integrated graphics. If raw compute is the goal, the 5800XT wins 15 of 17 benchmarks. If portability and per-core efficiency are priorities, the 8640U’s two wins and lower power draw make it the logical pick. The 16% Cinebench gap in favor of the 5800XT is consistent, but the 8640U’s 5.6% single-thread victory suggests that for everyday, lightly-threaded tasks, the newer architecture closes the gap.