AMD Ryzen 9 3900XT vs AMD Ryzen 9 PRO 6950H Comparison

FAQ

Q: Which processor has more cores and threads?

A: The AMD Ryzen 9 3900XT has 12 cores and 24 threads, while the AMD Ryzen 9 PRO 6950H has 8 cores and 16 threads.

Q: What is the difference in boost clock between the two?

A: The Ryzen 9 PRO 6950H boosts higher at 4.90 GHz compared to the Ryzen 9 3900XT's 4.70 GHz. However, the 3900XT has a higher base clock at 3.90 GHz versus 3.30 GHz.

Q: Which chip supports faster memory bandwidth?

A: The Ryzen 9 PRO 6950H supports DDR5 memory with a bandwidth of 76.8 GB/s, while the Ryzen 9 3900XT supports DDR4 with a bandwidth of 51.2 GB/s.

Q: Do both processors have integrated graphics?

A: No. The Ryzen 9 PRO 6950H includes Radeon 680M integrated graphics, while the Ryzen 9 3900XT has no integrated graphics.

Q: How do their average benchmark scores compare?

A: The Ryzen 9 3900XT has an average benchmark score of 33736, placing it in the 84th percentile. The Ryzen 9 PRO 6950H scores 33201, placing it in the 83rd percentile.

Q: Which processor has a larger L3 cache?

A: The Ryzen 9 3900XT has 64 MB of L3 cache, whereas the Ryzen 9 PRO 6950H has 16 MB (shared).

Architecture Differences

The two processors represent distinct architectural generations and market segments. The Ryzen 9 3900XT is a desktop part built on Zen 2 architecture with the codename Matisse 2, manufactured on TSMC's 7 nm process. It uses a chiplet design with a die size of 2x 74 mm² and contains 7,600 million transistors. The Ryzen 9 PRO 6950H, in contrast, is a mobile processor based on Zen 3+ architecture with the codename Rembrandt, built on a 6 nm process with a monolithic die size of 208 mm².

The core configuration differs significantly. The 3900XT offers 12 cores and 24 threads, while the 6950H provides 8 cores and 16 threads. This core advantage is a primary driver of the desktop chip's dominance in multi-threaded workloads. The cache hierarchy also diverges: both share 64 KB of L1 and 512 KB of L2 per core, but the 3900XT has 64 MB of L3 cache versus 16 MB on the 6950H.

Memory architecture separates them further. The 3900XT uses DDR4 with dual-channel support and 51.2 GB/s bandwidth. The 6950H uses newer DDR5 with dual-channel support and a higher 76.8 GB/s bandwidth. The mobile chip also includes integrated Radeon 680M graphics, a feature absent on the desktop part.

Platform differences are substantial. The 3900XT uses AMD Socket AM4 with PCIe Gen 4 and 24 lanes (CPU only), and has an unlocked multiplier for overclocking. The 6950H uses AMD Socket FP7 with PCIe Gen 4 and 20 lanes (CPU only), and has a locked multiplier. The desktop chip has a TDP of 105 watts, while the mobile chip is rated at 45 watts. The 3900XT launched in July 2020 with a launch MSRP of $499, while the 6950H arrived in April 2022.

The Verdict

The benchmark data presents a clear picture: the Ryzen 9 3900XT wins 14 of the 17 head-to-head comparisons, while the Ryzen 9 PRO 6950H wins only 3. The desktop processor's 12-core configuration delivers massive advantages in multi-threaded workloads. In Cinebench R23 multi-core, the 3900XT scores 27688 against the 6950H's 13501, a 105.1% advantage. This is the largest performance gap in the entire comparison.

The 3900XT also leads in memory-sensitive and integer-heavy tasks. PassMark data compression shows a 51.8% lead, data encryption a 53.3% lead, and find prime numbers a 245.2% lead. These results reflect both the core count advantage and the larger L3 cache.

However, the 6950H wins in single-threaded performance. Geekbench single-core shows the mobile chip ahead by 17.8% (1996 versus 1640), and PassMark single-thread shows a 17.6% lead (3326 versus 2742). The higher boost clock of 4.90 GHz and the newer Zen 3+ architecture contribute to this result.

The choice depends on the use case. For desktop users running heavily threaded applications, rendering, compilation, or scientific workloads, the 3900XT is the clear choice. Its 12 cores and 24 threads, combined with 64 MB of L3 cache, deliver class-leading multi-threaded performance. For mobile users prioritizing single-thread responsiveness, battery life (45 watt TDP), and integrated graphics, the 6950H offers a compelling package despite lower multi-core scores.

Specification Differences

| Specification | AMD Ryzen 9 3900XT | AMD Ryzen 9 PRO 6950H |

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

| Cores | 12 | 8 |

| Threads | 24 | 16 |

| Base Clock | 3.90 GHz | 3.30 GHz |

| Boost Clock | 4.70 GHz | 4.90 GHz |

| TDP | 105 W | 45 W |

| Socket | AMD Socket AM4 | AMD Socket FP7 |

| Architecture | Zen 2 | Zen 3+ |

| Codename | Matisse 2 | Rembrandt |

| Process Node | 7 nm | 6 nm |

| Die Size | 2x 74 mm² | 208 mm² |

| Transistors | 7,600 million | Not specified |

| L3 Cache | 64 MB | 16 MB (shared) |

| Memory Support | DDR4 | DDR5 |

| Memory Bandwidth | 51.2 GB/s | 76.8 GB/s |

| PCIe | Gen 4, 24 Lanes | Gen 4, 20 Lanes |

| Integrated Graphics | None | Radeon 680M |

| Multiplier Unlocked | Yes | No |

| Market Segment | Desktop | Mobile |

| Launch MSRP | $499 | Not specified |

Head-to-Head Benchmarks

The most striking result is in Cinebench R23 multi-core, where the 3900XT scores 27688 versus the 6950H's 13501, a 105.1% advantage. This more than doubles the mobile chip's output and underscores the value of 12 cores over 8. The Cinebench R15 multi-core test shows a similar pattern, with the 3900XT leading 2790 to 2153, a 29.6% margin.

Single-core Cinebench results are counterintuitive given the 6950H's higher boost clock. In Cinebench R15 single-core, the 3900XT wins 393 to 260, a 51.2% lead. In Cinebench R23 single-core, the 3900XT wins 3909 to 1615, a 142% lead. These results suggest the desktop chip's Zen 2 architecture sustains higher single-thread performance in this workload despite the newer Zen 3+ design.

Geekbench splits the difference. In multi-core, the 3900XT leads 11329 to 9571, an 18.4% advantage. But in single-core, the 6950H reverses the trend, winning 1996 to 1640, a 17.8% lead. This indicates the mobile chip's architectural improvements yield tangible single-thread benefits in certain workloads.

PassMark results heavily favor the 3900XT. The largest delta is in find prime numbers, where the desktop chip scores 214 versus 62, a 245.2% advantage. This test is highly sensitive to core count and cache size, both of which favor the 3900XT. Data compression shows a 51.8% lead (452328 versus 297936), and data encryption shows a 53.3% lead (28634 versus 18673). Extended instructions favor the 3900XT by 40.8% (28586 versus 20302).

Floating-point and integer math also favor the desktop chip, though by smaller margins. Floating-point math shows a 19.9% lead (58513 versus 48821), while integer math shows a 14.4% lead (99722 versus 87132). The PassMark multi-thread score gives the 3900XT a 37% advantage (32575 versus 23770). Physics testing shows a 59.3% lead (1776 versus 1115), and random string sorting shows a 56.6% lead (48327 versus 30859).

The 6950H wins only in PassMark single-thread tests, scoring 3326 versus 2742, a 17.6% advantage. This is consistent with the Geekbench single-core result and reflects the mobile chip's higher boost clock and newer architecture. However, these two wins are insufficient to offset the desktop chip's dominance across the broader benchmark suite.

The average benchmark scores confirm the overall picture: the 3900T averages 33736, just 1.6% ahead of the 6950H's 33201. Both processors sit in the 83rd to 84th percentile of all CPUs, indicating they are closely matched in overall capability despite their different strengths and weaknesses.