AMD Ryzen 9 PRO 9955 vs Intel Xeon 658X Comparison

The benchmark data presents a clear dichotomy: the Intel Xeon 658X is a multi-threaded powerhouse that dominates nearly every parallel workload, while the AMD Ryzen 9 PRO 9955 claims a decisive victory in single-threaded performance. The Intel part wins 9 of 11 head-to-head tests, often by massive margins, but the AMD chip’s 18.9% lead in single-thread score signals a fundamental architectural difference that buyers must weigh carefully.

Head-to-Head Benchmarks

The Xeon 658X’s most emphatic win comes in the PassMark physics test, where it scores 6,470 against the Ryzen’s 3,332 — a 94.2% advantage. This is not a marginal gap; it is nearly double the throughput, indicating the Intel processor’s 24 cores and 48 threads are being fully utilized in simulation-heavy workloads. Floating-point math tells a similar story: Intel scores 210,480 versus 121,509, a 73.2% lead that underscores its advantage in scientific computing and rendering tasks.

The margin narrows but remains substantial in integer math, where the Xeon posts 263,995 against 182,312, a 44.8% delta. Data compression shows Intel at 1,062,062 versus 684,470, a 55.2% lead, while encryption follows at 52,357 versus 33,754, a 55.1% advantage. These results are consistent: the Xeon’s higher core count and larger cache deliver between 33.9% and 94.2% more performance in every multi-threaded discipline tested.

The extended instructions test confirms the pattern, with Intel at 84,626 versus 54,903, a 54.1% delta. Even in prime number finding, a workload that often scales poorly, Intel wins 649 to 461, a 40.8% margin. Random string sorting goes to Intel at 103,028 versus 71,928, a 43.2% lead. The overall multithread score — 73,490 versus 54,866 — shows a 33.9% advantage for Intel, which is the smallest multi-core win but still a decisive one.

The single exception is stark. In the PassMark single-thread test, AMD wins 4,597 to 3,728, an 18.9% delta. This is the only benchmark where the Ryzen 9 PRO 9955 takes the lead, but it is a critical one for responsiveness and lightly-threaded applications. The data shows that AMD’s higher boost clock and newer process node translate directly into faster per-core execution, while Intel’s advantage is purely a function of core count and cache size.

Architecture Differences

The two processors diverge fundamentally in design philosophy. The Intel Xeon 658X uses the Granite Rapids architecture on a 5 nm process from Intel’s own foundry, with a die size of 2x 598 mm². It packs 24 cores and 48 threads, with a base clock of 3.00 GHz and a boost clock of 4.90 GHz. The cache hierarchy is generous: 112 KB of L1 per core, 2 MB of L2 per core, and 144 MB of shared L3. This massive L3 cache is a key factor in its multi-threaded dominance, allowing more working set to stay on-die.

The AMD Ryzen 9 PRO 9955, by contrast, uses the Granite Ridge architecture on a 4 nm process from TSMC, with a die size of 2x 70.6 mm². It has 12 cores and 24 threads, but runs at a higher 3.40 GHz base and 5.40 GHz boost. The cache is smaller per core — 80 KB L1 and 1 MB L2 — with 64 MB of shared L3. AMD’s process advantage is clear: the 4 nm node and smaller die allow higher clock speeds and better power efficiency, as reflected in its 120 W TDP versus Intel’s 250 W.

Memory architecture also differs sharply. The Xeon supports DDR5 over an eight-channel bus with 409.6 GB/s of bandwidth, while the Ryzen uses dual-channel DDR5 with 89.6 GB/s. This explains part of the Xeon’s multi-threaded lead — it can feed its cores far more data per second. The Xeon also offers 128 PCIe Gen 5 lanes (CPU only) versus 24 lanes on the Ryzen, making it the clear choice for high-bandwidth peripheral expansion. The Ryzen does include integrated Radeon Graphics, while the Xeon has none. Both support ECC memory, and both are unlocked, though the Ryzen’s multiplier is locked.

The Verdict

The data is unambiguous for heavily parallel workloads. The Intel Xeon 658X wins 9 of 11 benchmarks, with margins ranging from 33.9% to 94.2%. Its 144 MB L3 cache, eight-channel memory, and 48 threads make it the superior choice for rendering, scientific simulation, data compression, and any task that can scale across many cores. The 250 W TDP is a cost of that performance, but for a server or workstation where throughput is paramount, the Xeon is the data-driven winner.

The AMD Ryzen 9 PRO 9955 is the better pick for single-threaded responsiveness. Its 18.9% lead in the single-thread test, combined with a 5.40 GHz boost clock and 4 nm process, makes it ideal for interactive applications, legacy software that uses few cores, or any workload where per-core speed matters more than raw core count. Its 120 W TDP also makes it far easier to cool and power, a factor the benchmark scores do not capture but which the specification data clearly shows.

Specification Differences

| Field | Intel Xeon 658X | AMD Ryzen 9 PRO 9955 |

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

| Cores | 24 | 12 |

| Threads | 48 | 24 |

| Base Clock | 3.00 GHz | 3.40 GHz |

| Boost Clock | 4.90 GHz | 5.40 GHz |

| TDP | 250 W | 120 W |

| Socket | Intel Socket 4710 | AMD Socket AM5 |

| Process Node | 5 nm | 4 nm |

| Foundry | Intel | TSMC |

| Die Size | 2x 598 mm² | 2x 70.6 mm² |

| L1 Cache | 112 KB (per core) | 80 KB (per core) |

| L2 Cache | 2 MB (per core) | 1 MB (per core) |

| L3 Cache | 144 MB (shared) | 64 MB |

| Memory Bus | Eight-channel | Dual-channel |

| Memory Bandwidth | 409.6 GB/s | 89.6 GB/s |

| PCIe | Gen 5, 128 Lanes | Gen 5, 24 Lanes |

| Integrated Graphics | N/A | Radeon Graphics |

| Transistors | Not listed | 16,630 million |

| Launch MSRP | $1699 | Not listed |

FAQ

Q: Which processor has more cores and threads?

A: The Intel Xeon 658X has 24 cores and 48 threads, exactly double the AMD Ryzen 9 PRO 9955’s 12 cores and 24 threads.

Q: How much faster is the Intel Xeon 658X in multi-threaded workloads?

A: The Xeon leads by 33.9% in the PassMark multithread score (73,490 vs 54,866), with the largest win being 94.2% in the physics test (6,470 vs 3,332).

Q: Does the AMD Ryzen 9 PRO 9955 win any benchmark?

A: Yes, it wins the PassMark single-thread test with a score of 4,597 versus 3,728, an 18.9% advantage over the Intel part.

Q: What is the memory bandwidth difference?

A: The Intel Xeon 658X supports eight-channel DDR5 with 409.6 GB/s, while the AMD Ryzen 9 PRO 9955 uses dual-channel DDR5 with 89.6 GB/s — a roughly 4.5x difference in theoretical bandwidth.

Q: Which processor has a higher boost clock?

A: The AMD Ryzen 9 PRO 9955 boosts to 5.40 GHz, while the Intel Xeon 658X reaches 4.90 GHz.

Q: Do both processors support ECC memory?

A: Yes, both the Intel Xeon 658X and the AMD Ryzen 9 PRO 9955 list ECC memory support as true.

Where Each One Wins

The Intel Xeon 658X is the clear choice for throughput-bound environments. Data compression shows a 55.2% lead (1,062,062 vs 684,470), making it ideal for backup systems, database archives, and file servers. The 73.2% advantage in floating-point math (210,480 vs 121,509) points to scientific computing, 3D rendering, and financial modeling. The 94.2% physics win (6,470 vs 3,332) targets engineering simulation and computational fluid dynamics. Its 128 PCIe Gen 5 lanes and 409.6 GB/s memory bandwidth make it suitable for high-performance computing clusters and AI training nodes where data movement is critical.

The AMD Ryzen 9 PRO 9955 wins the single-thread crown with 4,597 versus 3,728, an 18.9% delta. This makes it the better fit for interactive workstations running legacy CAD software, single-threaded scripting, or office productivity suites that do not scale across cores. Its 120 W TDP and integrated Radeon Graphics also position it for compact or power-sensitive deployments where the Xeon’s 250 W draw and lack of integrated graphics would be prohibitive. For a developer who needs fast compilation of small projects or a researcher running single-threaded analysis tools, the Ryzen’s higher clock speed is the decisive factor. The Xeon wins on raw throughput; the Ryzen wins on responsiveness and efficiency.