CPU Comparison

The Intel Core i5-8400 and AMD EPYC 9174F occupy opposite ends of the computing spectrum, and the benchmark data reflects that divide clearly. The EPYC 9174F wins every single head-to-head test in this comparison, with margins ranging from roughly 40% to over 80%. However, the i5-8400, a 6-core desktop part from 2017, still holds its own in the aggregate percentile rankings, sitting at the 68th percentile versus the EPYC’s 67th. This suggests that while the EPYC dominates in raw throughput, the i5-8400’s overall standing across a wider benchmark suite is not as far behind as the direct comparison might imply. The data tells a story of two very different tools built for very different jobs.

Where Each One Wins

The EPYC 9174F is the clear winner in every benchmark category where both processors have recorded scores. In multi-threaded workloads, its advantage is overwhelming. The Cinebench R23 multi-core test shows the EPYC scoring 46489 against the i5-8400’s 7847, a gap that translates to the EPYC being roughly 5.9 times faster. Similarly, in Geekbench multi-core, the EPYC’s 17363 dwarfs the i5-8400’s 5088, a 70.7% difference in favor of the AMD part. These are not incremental gains; they represent a fundamental shift in capability for heavily parallel tasks like rendering, simulation, and server-side processing.

Single-threaded performance also favors the EPYC, though by a smaller margin. The Cinebench R23 single-core test shows the EPYC at 6563 versus the i5-8400’s 1107, an 83.1% delta. In Geekbench single-core, the EPYC’s 2244 beats the i5-8400’s 1353 by 39.7%. While the EPYC still wins decisively, the narrower gap in single-core tests suggests that the i5-8400’s architecture, despite its age, is not completely outclassed in lightly-threaded scenarios. The i5-8400 does have a notable advantage in one area: it includes integrated graphics (UHD Graphics 630), while the EPYC 9174F has none. For a system that requires display output without a discrete GPU, the i5-8400 is the only option here.

Architecture Differences

The architectural gap between these two processors is vast, explaining the performance differential. The i5-8400 is built on Intel’s 14 nm process, featuring 6 cores and 6 threads with a base clock of 2.80 GHz and a boost clock of 4.00 GHz. Its cache layout includes 64 KB of L1 per core, 256 KB of L2 per core, and a shared 9 MB L3 cache. It supports dual-channel DDR4 memory with a bandwidth of 42.7 GB/s and uses PCIe Gen 3 with 16 lanes from the CPU. The die size is 154 mm².

The EPYC 9174F, in contrast, is a Zen 4 (Genoa) part built on TSMC’s 5 nm process, containing 16 cores and 32 threads. Its base clock is 4.10 GHz with a boost clock of 4.40 GHz. The cache hierarchy is dramatically different: 64 KB of L1 per core, 1 MB of L2 per core, and a massive 256 MB of shared L3 cache. The transistor count is listed at 52,560 million, spread across 8 chiplets each measuring 72 mm². It supports twelve-channel DDR5 memory with a bandwidth of 460.8 GB/s and offers PCIe Gen 5 with 128 lanes from the CPU. ECC memory is supported on the EPYC but not on the i5-8400.

The process node difference alone (14 nm vs 5 nm) explains much of the efficiency and clock speed advantage of the EPYC. The EPYC’s 320 W TDP is far higher than the i5-8400’s 65 W, but it also delivers nearly six times the multi-core performance in Cinebench R23. The memory subsystem is another major differentiator: the EPYC’s twelve-channel DDR5 interface provides over ten times the theoretical bandwidth of the i5-8400’s dual-channel DDR4, a critical factor for server workloads that move large datasets.

Head-to-Head Benchmarks

The head-to-head results are one-sided, with the EPYC 9174F winning all 8 recorded tests. The largest margins appear in multi-core Cinebench tests. In Cinebench R15 multi-core, the EPYC scores 4686 against the i5-8400’s 790, a delta of -83.1% for the Intel part. The R20 multi-core test shows a similar pattern: 19525 for the EPYC versus 3295 for the i5-8400, again a -83.1% difference. The R23 multi-core result repeats this exact delta, with scores of 46489 and 7847 respectively. The consistency of the -83.1% delta across all three Cinebench multi-core versions indicates a stable performance ratio regardless of the workload’s specific demands.

Single-core Cinebench results are also decisively in the EPYC’s favor, though the deltas are slightly larger. In R15 single-core, the EPYC’s 661 beats the i5-8400’s 111 by -83.2%. The R20 single-core test shows 2756 versus 464, also -83.2%. R23 single-core records 6563 versus 1107, a -83.1% delta. These numbers suggest that the EPYC’s Zen 4 architecture provides a substantial IPC improvement over the older Coffee Lake design, not just more cores.

Geekbench results tell a slightly different story. The multi-core test shows the EPYC at 17363 versus 5088, a -70.7% delta. This is a smaller margin than the Cinebench multi-core tests, implying that Geekbench scales differently with core count or memory bandwidth. The single-core Geekbench test shows the smallest gap of all: 2244 for the EPYC versus 1353 for the i5-8400, a -39.7% delta. This indicates that in a purely single-threaded, integer-heavy workload, the i5-8400 is relatively more competitive, though it still loses by a significant margin.

FAQ

Q: Which processor has a higher boost clock?

A: The AMD EPYC 9174F has a higher boost clock at 4.40 GHz, compared to the Intel Core i5-8400’s 4.00 GHz.

Q: Does the Intel Core i5-8400 support ECC memory?

A: No, the i5-8400 does not support ECC memory. The EPYC 9174F does support ECC memory.

Q: Which processor has more L3 cache?

A: The AMD EPYC 9174F has 256 MB of shared L3 cache, while the Intel Core i5-8400 has 9 MB of shared L3 cache.

Q: How many PCIe lanes does each processor provide?

A: The EPYC 9174F provides 128 PCIe Gen 5 lanes from the CPU, while the i5-8400 provides 16 PCIe Gen 3 lanes from the CPU.

Q: What is the memory bandwidth difference between the two?

A: The EPYC 9174F has a memory bandwidth of 460.8 GB/s via twelve-channel DDR5, while the i5-8400 has 42.7 GB/s via dual-channel DDR4.

Q: Which processor is currently in production?

A: The AMD EPYC 9174F is marked as “Active” in production status, while the Intel Core i5-8400 is listed as “End-of-life.”

The Verdict

The data is unambiguous: the AMD EPYC 9174F is the superior processor for any workload that benefits from multi-core throughput, memory bandwidth, or raw single-thread speed. It wins every head-to-head benchmark, often by margins exceeding 80%. For server, workstation, or heavy rendering tasks, the EPYC 9174F is the only choice between these two. Its 16 cores and 32 threads, combined with 256 MB of L3 cache and twelve-channel DDR5 memory, make it a purpose-built powerhouse.

The Intel Core i5-8400, however, should not be dismissed entirely. Its 65 W TDP is dramatically lower than the EPYC’s 320 W, making it suitable for power-constrained desktop builds. It also includes integrated graphics, which the EPYC lacks entirely, meaning a system based on the i5-8400 can operate without a discrete GPU. For a basic desktop, office, or light media PC, the i5-8400 provides adequate performance at a fraction of the power draw. The i5-8400’s 68th percentile ranking versus the EPYC’s 67th also shows that in the broader context of all CPUs, the i5-8400 is not far behind on average benchmark scores, despite losing every direct comparison here.

Specification Differences

The following table highlights only the fields where the two processors differ:

| Specification | Intel Core i5-8400 | AMD EPYC 9174F |

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

| Cores | 6 | 16 |

| Threads | 6 | 32 |

| Base Clock | 2.80 GHz | 4.10 GHz |

| Boost Clock | 4.00 GHz | 4.40 GHz |

| TDP | 65 W | 320 W |

| Socket | Intel Socket 1151 | AMD Socket SP5 |

| Architecture | Coffee Lake | Zen 4 |

| Codename | Coffee Lake | Genoa |

| Generation | Core i5 (Coffee Lake) | EPYC (Zen 4 (Genoa)) |

| Process Node | 14 nm | 5 nm |

| Foundry | Intel | TSMC |

| Transistors | Not listed | 52,560 million |

| Die Size | 154 mm² | 8x 72 mm² |

| L2 Cache | 256 KB (per core) | 1 MB (per core) |

| L3 Cache | 9 MB (shared) | 256 MB (shared) |

| Memory Support | DDR4 | DDR5 |

| Memory Bus | Dual-channel | Twelve-channel |

| Memory Bandwidth | 42.7 GB/s | 460.8 GB/s |

| ECC Memory | No | Yes |

| PCIe | Gen 3, 16 Lanes | Gen 5, 128 Lanes |

| Integrated Graphics | UHD Graphics 630 | None |

| Market Segment | Desktop | Server/Workstation |

| Production Status | End-of-life | Active |

| Release Date | 2017-10-04 | 2022-11-09 |

| Launch MSRP | $182 | $3850 |