AMD Ryzen 5 PRO 8640U vs AMD Ryzen 7 3800X Comparison

Head-to-Head Benchmarks

The recorded data shows a clear split between the two processors, with the mobile AMD Ryzen 5 PRO 8640U taking 10 of the 17 head-to-head benchmark comparisons, while the desktop AMD Ryzen 7 3800X wins the remaining 7. The most decisive victory for the Ryzen 5 PRO 8640U comes in the Passmark single-thread test, where it scores 3732 against the 3800X’s 2712, a 37.6% advantage. This is the largest margin in either direction across the entire benchmark set and highlights the architectural efficiency of the newer Zen 4 design.

The Ryzen 5 PRO 8640U also dominates the Cinebench suite. In Cinebench R23 multi-core, it scores 19982 versus 19588 for the 3800X, a 2% lead. The single-core results follow the same pattern: 2821 versus 2765, again a 2% margin. In Cinebench R15, the 8640U scores 2014 multi-core and 284 single-core, compared to 1974 and 278 for the 3800X, representing 2% and 2.2% advantages respectively. The R20 results are consistent, with the 8640U posting 8392 multi-core and 1184 single-core against the 3800X’s 8226 and 1161, both 2% leads.

Floating-point and integer math workloads also favor the newer chip. In Passmark floating-point math, the 8640U scores 45265, a 13.8% improvement over the 3800X’s 39759. Integer math shows a 10.6% lead, with 74875 versus 67725. These results indicate that despite having fewer physical cores, the Zen 4 architecture delivers substantially higher per-core throughput in compute-heavy tasks.

The Ryzen 7 3800X fights back in several specialized workloads. Its largest win comes in Passmark data encryption, scoring 19337 versus 15843, an 18.1% advantage. Data compression favors the 3800X at 304853 against 260925, a 14.4% gap. The 3800X also leads in prime number finding (103 versus 78, a 24.3% margin), extended instructions (20037 versus 19130, 4.5% ahead), multithread (23046 versus 22795, 1.1% ahead), physics (1226 versus 1154, 5.9% ahead), and random string sorting (32869 versus 32114, 2.3% ahead). These wins suggest the 3800X’s extra two cores and larger L3 cache provide tangible benefits in specific data-intensive patterns.

Overall average benchmark scores from the database place the 8640U at 30254, slightly above the 3800X’s 29447. Both processors sit at the 81st percentile among all CPUs, indicating similar overall positioning. The 8640U’s nearest rivals include the AMD Ryzen 7 2700X with an average score of 30213 (0.1% lower), the Ryzen 7 7736U at 30364 (0.4% higher), and the Intel Core i9-11980HK at 30422 (0.6% higher). The 3800X’s closest competitors include the AMD Ryzen AI 7 345 at 29461, the AMD EPYC 9654 at 29409, and the Intel Core i5-13500HX at 29270.

Architecture Differences

The two processors come from fundamentally different design eras. The AMD Ryzen 5 PRO 8640U uses the Zen 4 architecture with the Hawk Point codename, built on a 4nm process at TSMC. It packs 25,000 million transistors into a 178 mm² die. The Ryzen 7 3800X uses Zen 2 with the Matisse codename, fabricated on a 7nm process, also at TSMC, with 3,800 million transistors on a much smaller 74 mm² die. The transistor count difference is substantial, but the 3800X’s smaller die reflects its simpler design and older process.

Core and thread counts differ: the 8640U offers 6 cores and 12 threads, while the 3800X provides 8 cores and 16 threads. Both have 64 KB of L1 cache per core. The L2 cache differs, with the 8640U offering 1 MB per core versus 512 KB per core for the 3800X. L3 cache is inverted in capacity: the 8640U has 16 MB shared, whereas the 3800X has 32 MB shared. This larger L3 cache on the 3800X likely explains some of its wins in compression and encryption workloads.

Memory support diverges significantly. The 8640U supports DDR5 memory with dual-channel access and a bandwidth of 89.6 GB/s. The 3800X supports DDR4, also dual-channel, with 51.2 GB/s bandwidth. The 8640U supports ECC memory; the 3800X does not. PCIe connectivity also differs: the 8640U provides Gen 4 with 20 lanes (CPU only), while the 3800X provides Gen 4 with 24 lanes (CPU only).

The 8640U includes integrated Radeon 760M graphics; the 3800X has no integrated graphics. The 8640U targets the mobile segment with a 28W TDP and an AMD Socket FP7. The 3800X is a desktop part with a 105W TDP on AMD Socket AM4. The 8640U has a locked multiplier, while the 3800X has an unlocked multiplier for overclocking. Base clocks are 3.50 GHz for the 8640U and 3.90 GHz for the 3800X, but boost clocks reverse this: 4.90 GHz for the 8640U versus 4.50 GHz for the 3800X.

Release dates place the 3800X in July 2019 and the 8640U in April 2024. The 3800X carries a launch MSRP of $399. The 8640U has no recorded launch MSRP in the database.

FAQ

Q: Which processor has the higher single-thread performance?

A: The AMD Ryzen 5 PRO 8640U is significantly ahead. In Passmark single-thread testing, it scores 3732 versus 2712 for the Ryzen 7 3800X, a 37.6% advantage. Cinebench R23 single-core confirms this with 2821 versus 2765, a 2% lead.

Q: Why does the Ryzen 7 3800X win in data encryption and compression?

A: The 3800X scores 19337 in Passmark data encryption versus 15843 for the 8640U, an 18.1% edge. In data compression, it posts 304853 against 260925, a 14.4% lead. The 3800X’s additional two cores and larger 32 MB L3 cache contribute to these results, as these workloads benefit from more cores and greater cache capacity.

Q: How do the processors compare in overall average benchmark scores?

A: The 8640U records an average benchmark score of 30254, while the 3800X averages 29447. Both processors sit at the 81st percentile among all CPUs, meaning they occupy a similar overall performance tier despite their architectural differences.

Q: Does the Ryzen 5 PRO 8640U support ECC memory?

A: Yes, the 8640U supports ECC memory. The Ryzen 7 3800X does not. This makes the 8640U more suitable for error-sensitive workloads where data integrity is critical.

Q: Which processor has the higher boost clock?

A: The Ryzen 5 PRO 8640U boosts to 4.90 GHz, while the Ryzen 7 3800X boosts to 4.50 GHz. The 3800X has a higher base clock at 3.90 GHz versus 3.50 GHz for the 8640U, but the 8640U reaches a higher maximum frequency.

Q: What are the memory bandwidth differences?

A: The 8640U supports DDR5 with 89.6 GB/s bandwidth, while the 3800X supports DDR4 with 51.2 GB/s. The 8640U offers substantially higher memory throughput, which benefits memory-sensitive workloads.

Specification Differences

The database records the following differences between the two processors:

• Cores: 6 (8640U) versus 8 (3800X)
• Threads: 12 (8640U) versus 16 (3800X)
• Base clock: 3.50 GHz (8640U) versus 3.90 GHz (3800X)
• Boost clock: 4.90 GHz (8640U) versus 4.50 GHz (3800X)
• TDP: 28W (8640U) versus 105W (3800X)
• Socket: AMD Socket FP7 (8640U) versus AMD Socket AM4 (3800X)
• Architecture: Zen 4 (8640U) versus Zen 2 (3800X)
• Codename: Hawk Point (8640U) versus Matisse (3800X)
• Process node: 4 nm (8640U) versus 7 nm (3800X)
• Transistors: 25,000 million (8640U) versus 3,800 million (3800X)
• Die size: 178 mm² (8640U) versus 74 mm² (3800X)
• L2 cache: 1 MB per core (8640U) versus 512 KB per core (3800X)
• L3 cache: 16 MB shared (8640U) versus 32 MB (3800X)
• Memory support: DDR5 (8640U) versus DDR4 (3800X)
• Memory bandwidth: 89.6 GB/s (8640U) versus 51.2 GB/s (3800X)
• ECC memory: Supported (8640U) versus not supported (3800X)
• PCIe lanes: 20 (8640U) versus 24 (3800X)
• Integrated graphics: Radeon 760M (8640U) versus none (3800X)
• Market segment: Mobile (8640U) versus Desktop (3800X)
• Multiplier unlocked: No (8640U) versus Yes (3800X)
• Release date: April 2024 (8640U) versus July 2019 (3800X)
• Launch MSRP: None recorded (8640U) versus $399 (3800X)

The Verdict

The benchmark data tells a nuanced story. The AMD Ryzen 5 PRO 8640U is the stronger all-around performer in most CPU-centric workloads, especially those that rely on single-thread speed and modern instruction efficiency. Its 37.6% lead in Passmark single-thread, 13.8% lead in floating-point math, and 10.6% lead in integer math demonstrate that Zen 4’s per-core capabilities vastly outpace Zen 2. For general productivity, software compilation, and lightly threaded tasks, the 8640U is the clear choice.

The Ryzen 7 3800X remains competitive in specific data-heavy scenarios. Its wins in encryption (18.1% ahead), compression (14.4% ahead), and prime number finding (24.3% ahead) indicate that workloads with high memory pressure and large working sets can still favor the older, larger-cache design. The 3800X’s 32 MB L3 cache versus 16 MB on the 8640U is a meaningful advantage in these cases.

The 8640U’s lower TDP of 28W versus 105W makes it dramatically more power-efficient, and the inclusion of integrated graphics means it can serve as a complete mobile platform without a discrete GPU. The 3800X requires a separate graphics solution. The 8640U also supports ECC memory and DDR5 with higher bandwidth, making it better suited for modern memory-intensive applications.

The 3800X’s unlocked multiplier appeals to overclockers, and its 8 cores provide a raw thread advantage that shows up in multithread (23046 versus 22795) and physics (1226 versus 1154) tests. However, these margins are slim, under 6% in both cases. The 3800X also offers more PCIe lanes (24 versus 20), which matters for expansion-heavy desktop builds.

For most users, the data supports choosing the Ryzen 5 PRO 8640U: it wins the majority of benchmarks, offers superior single-thread performance, consumes far less power, and includes modern platform features. The Ryzen 7 3800X is only preferable in niche workloads that specifically benefit from its larger cache and extra cores, such as data compression and encryption pipelines, or for users who require an unlocked multiplier for manual overclocking. The average benchmark scores (30254 versus 29447) and identical 81st percentile ranking reinforce that the 8640U is the newer, more efficient, and generally faster processor.