AMD EPYC 4345P vs AMD Ryzen 9 5900 Comparison

FAQ

Q: Which processor is faster in multi-threaded workloads?

A: The AMD EPYC 4345P wins the multi-threaded comparisons. It scores 32,020 in Cinebench R23 multi-core versus 28,834 for the Ryzen 9 5900, an 11% advantage. It also leads in PassMark multithread with 36,123 against 33,969.

Q: How big is the single-thread performance gap?

A: The EPYC 4345P is substantially ahead. In Cinebench R23 single-core it scores 4,520 versus 4,070, an 11.1% lead. In PassMark single-thread, the gap widens to 28.2%, with scores of 4,408 versus 3,439.

Q: Does the Ryzen 9 5900 win any benchmark categories?

A: Yes, three of the seventeen recorded tests. The Ryzen 9 5900 wins PassMark data encryption (26,247 versus 23,313), PassMark find prime numbers (213 versus 167), and PassMark integer math (128,641 versus 123,774).

Q: What is the difference in overall benchmark averages?

A: The EPYC 4345P has an average benchmark score of 48,470, while the Ryzen 9 5900 averages 46,971. The EPYC sits at the 90th percentile of all CPUs, the Ryzen 9 at the 89th.

Q: Which processor supports DDR5 memory?

A: The AMD EPYC 4345P supports DDR5 with dual-channel memory and 89.6 GB/s bandwidth. The Ryzen 9 5900 uses DDR4 with dual-channel memory and 51.2 GB/s bandwidth.

Q: Are both processors unlocked for overclocking?

A: No. The Ryzen 9 5900 has an unlocked multiplier. The EPYC 4345P does not have an unlocked multiplier.

Architecture Differences

The EPYC 4345P uses the Zen 5 architecture on TSMC's 4 nm process, while the Ryzen 9 5900 is built on Zen 3 using TSMC's 7 nm node. The process shrink allows the EPYC to fit 8,315 million transistors on a 70.6 mm² die. The Ryzen 9 uses 8,300 million transistors spread across two 74 mm² dies.

Core counts differ significantly. The EPYC 4345P has 8 cores and 16 threads. The Ryzen 9 5900 has 12 cores and 24 threads. Despite having 50% more cores, the Ryzen 9 cannot overcome the per-core efficiency advantage of the newer Zen 5 design in most tests.

Cache organization is notably different. The EPYC 4345P provides 80 KB of L1 per core, 1 MB of L2 per core, and 32 MB of shared L3 cache. The Ryzen 9 5900 offers 64 KB of L1 per core, 512 KB of L2 per core, and 64 MB of L3 cache. The Ryzen 9 has double the L3 capacity, but the EPYC's per-core L1 and L2 are larger.

Clock speeds favor the EPYC 4345P. It has a base clock of 3.80 GHz and a boost clock of 5.50 GHz. The Ryzen 9 5900 runs at 3.00 GHz base and 4.70 GHz boost. Both processors share a 65 W TDP, which makes the EPYC's clock advantage notable at the same power envelope.

Memory support diverges completely. The EPYC 4345P is designed for DDR5 and offers 89.6 GB/s of bandwidth. The Ryzen 9 5900 pairs with DDR4 and delivers 51.2 GB/s. Both use dual-channel memory buses and both support ECC memory.

PCIe capabilities differ as well. The EPYC 4345P provides PCIe Gen 5 with 24 CPU lanes. The Ryzen 9 5900 has PCIe Gen 4 with 20 CPU lanes. The EPYC also includes integrated Radeon Graphics, while the Ryzen 9 has no integrated graphics.

The sockets are incompatible. The EPYC 4345P uses AMD Socket AM5, while the Ryzen 9 5900 uses AMD Socket AM4. The EPYC belongs to the EPYC 4005 series and targets the server and workstation market segment. The Ryzen 9 is part of the 5000 series and targets desktop systems.

Where Each One Wins

The EPYC 4345P dominates the Cinebench suite entirely. It wins all six Cinebench R15, R20, and R23 tests, both multi-core and single-core, with margins between 11% and 11.1%. This makes it the clear choice for rendering, 3D modeling, and any workload that scales with sustained all-core or single-core throughput.

In PassMark tests, the EPYC 4345P wins nine of twelve categories. Its largest victory is in physics, where it scores 2,583 versus 1,697, a 52.2% advantage. This suggests a major uplift in physics simulation and related computational tasks. It also wins extended instructions by 17.9%, floating point math by 7.4%, random string sorting by 6.6%, and data compression by 2.4%.

The Ryzen 9 5900 takes three specific niches. It wins data encryption by 11.2%, indicating stronger performance in cryptographic workloads. It wins prime number finding by 21.6%, a test that often rewards raw integer throughput per core. It also wins integer math by 3.8%, a smaller margin but still a genuine lead.

For multi-threaded productivity, the EPYC 4345P holds the edge despite fewer cores. The PassMark multithread score of 36,123 versus 33,969 (6.3% lead) shows that Zen 5's architectural efficiency more than compensates for the Ryzen 9's additional 4 cores and 8 threads.

The Ryzen 9 5900 remains relevant for specific integer-heavy and encryption tasks. Users running encryption workloads or prime-number sieving should consider the Ryzen 9. For everything else in the recorded data, the EPYC 4345P is faster.

Specification Differences

| Specification | AMD EPYC 4345P | AMD Ryzen 9 5900 |

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

| Cores | 8 | 12 |

| Threads | 16 | 24 |

| Base Clock | 3.80 GHz | 3.00 GHz |

| Boost Clock | 5.50 GHz | 4.70 GHz |

| Socket | AMD Socket AM5 | AMD Socket AM4 |

| Architecture | Zen 5 | Zen 3 |

| Process Node | 4 nm | 7 nm |

| Transistors | 8,315 million | 8,300 million |

| Die Size | 70.6 mm² | 2x 74 mm² |

| L1 Cache | 80 KB (per core) | 64 KB (per core) |

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

| L3 Cache | 32 MB (shared) | 64 MB |

| Memory Support | DDR5 | DDR4 |

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

| PCIe | Gen 5, 24 Lanes (CPU only) | Gen 4, 20 Lanes (CPU only) |

| Integrated Graphics | Radeon Graphics | None |

| Market Segment | Server/Workstation | Desktop |

| Multiplier Unlocked | No | Yes |

| Release Date | 2025-05-12 | 2021-01-11 |

Head-to-Head Benchmarks

The Cinebench results are uniformly one-sided. In Cinebench R15 multi-core, the EPYC 4345P scores 3,227 versus 2,906, an 11% lead. The single-core R15 test shows 455 versus 410, another 11% margin. Cinebench R20 multi-core delivers 13,448 against 12,110, and R20 single-core gives 1,898 versus 1,709, an 11.1% gap. Cinebench R23 multi-core produces 32,020 against 28,834, and single-core yields 4,520 versus 4,070. Every Cinebench test favors the EPYC 4345P by roughly 11%.

The PassMark physics test is the largest single delta in the entire comparison. The EPYC 4345P scores 2,583, while the Ryzen 9 5900 manages only 1,697. That is a 52.2% advantage for the EPYC. No other test comes close to this margin.

PassMark single-thread results show a strong EPYC lead. The score is 4,408 versus 3,439, a 28.2% difference. This test appears twice in the database with identical values, confirming the consistency of the measurement.

Extended instructions favor the EPYC 4345P by 17.9%, with scores of 31,663 versus 26,859. Floating point math goes to the EPYC at 74,255 versus 69,124, a 7.4% margin. Random string sorting favors the EPYC at 46,238 versus 43,386, a 6.6% lead. Data compression is close, with the EPYC ahead 421,490 versus 411,453, a 2.4% margin.

The Ryzen 9 5900 takes its largest win in prime number finding. It scores 213 versus 167, a 21.6% advantage. Data encryption goes to the Ryzen 9 at 26,247 versus 23,313, an 11.2% lead. Integer math favors the Ryzen 9 at 128,641 versus 123,774, a 3.8% margin.

The overall win tally is decisive. The EPYC 4345P wins 14 of 17 head-to-head benchmarks. The Ryzen 9 5900 wins 3.

The Verdict

The data points clearly to the AMD EPYC 4345P for most buyers. It wins 14 of 17 benchmarks, including every Cinebench test and the PassMark multithread score. Its single-thread advantage of 28.2% in PassMark and 11.1% in Cinebench R23 makes it the stronger choice for responsiveness and lightly threaded applications. The physics test result, a 52.2% lead, suggests a major improvement in simulation-heavy workloads.

The EPYC 4345P achieves these results with fewer cores. It has 8 cores and 16 threads versus the Ryzen 9 5900's 12 cores and 24 threads. The Zen 5 architecture on 4 nm, higher clocks (5.50 GHz boost versus 4.70 GHz), and faster DDR5 memory (89.6 GB/s versus 51.2 GB/s) more than compensate for the core deficit. The EPYC also provides PCIe Gen 5 with 24 lanes, which suits current expansion cards and storage.

The Ryzen 9 5900 retains a narrow but real niche. It wins data encryption, prime number finding, and integer math. Users running cryptographic workloads or integer-bound algorithms should pick the Ryzen 9. Its 21.6% lead in prime number finding is substantial, and the 11.2% encryption advantage is meaningful.

The Ryzen 9 also offers an unlocked multiplier, which the EPYC does not. Enthusiasts who plan to overclock may prefer the Ryzen 9. It also uses the AM4 socket, which may be relevant for users upgrading an existing platform, though the EPYC uses the newer AM5 socket.

For server and workstation deployments, the EPYC 4345P is the obvious choice. It is built for that market segment, includes integrated graphics, supports ECC memory, and delivers better performance in the majority of tests. The launch MSRP is $329.

For desktop users who need maximum integer throughput or encryption speed, the Ryzen 9 5900 remains competitive. For everyone else, the recorded benchmarks favor the EPYC 4345P in almost every meaningful category. The average benchmark scores reflect this: 48,470 for the EPYC versus 46,971 for the Ryzen 9. The EPYC also sits at the 90th percentile of all CPUs, one point above the Ryzen 9's 89th percentile.

Choose the EPYC 4345P for general performance, rendering, physics, and modern platform features. Choose the Ryzen 9 5900 only if your workload is specifically dominated by encryption or integer math.