CPU Comparison

Intel Xeon E-2378 and Intel Core i9-9900 are both 8-core, 16-thread processors built on Intel's 14 nm process, yet they target different market segments and deliver measurably distinct performance profiles. The Xeon E-2378 is a server/workstation part from the Xeon E-2300 series, while the Core i9-9900 is a desktop processor from the Coffee Lake Refresh generation. Benchmark data from Cinebench R15, R20, and R23 shows the Xeon E-2378 winning all six head-to-head comparisons by a consistent margin of roughly 8.3–8.4%. Despite this, both processors occupy the same 57th percentile among all CPUs, with average benchmark scores of 4232 for the Xeon and 4163 for the Core i9.

Where Each One Wins

The performance split between these two is unambiguous according to the benchmark results. The Intel Xeon E-2378 wins every single test in the comparison suite, including all three Cinebench versions in both multi-core and single-core modes. Its advantages range from 8.3% to 8.4% across the board, making it the clear choice for any workload that benefits from Cinebench-style rendering or computational throughput.

The Core i9-9900, however, does not win a single benchmark in this dataset. That said, its performance is not far behind; the margin is consistently tight, sitting at roughly 8% in every test. Where the Core i9-9900 can still claim relevance is in its ecosystem positioning. As a desktop part, it pairs with Intel Socket 1151 and includes integrated UHD Graphics 630, which the Xeon lacks entirely. This makes the Core i9-9900 suitable for systems where a discrete GPU is not mandatory, while the Xeon E-2378 requires one.

For multi-threaded workloads like video rendering or scientific computing, the Xeon E-2378’s lead in Cinebench R23 multi-core (14633 vs 13509) is the most decisive advantage. For single-threaded tasks, the Xeon E-2378’s 2065 score in Cinebench R23 single-core versus 1907 for the Core i9-9900 shows a similar edge, indicating the Xeon holds its advantage in both parallel and serial execution.

Architecture Differences

The architectural gap between these two processors is rooted in their respective generations and target platforms. The Xeon E-2378 uses the Rocket Lake architecture, specifically the Rocket Lake-E variant, while the Core i9-9900 is based on Coffee Lake, specifically Coffee Lake-R. Both are fabricated on Intel’s 14 nm process, but the die sizes differ considerably: the Xeon E-2378 has a 276 mm² die, whereas the Core i9-9900 is smaller at 180.3 mm².

Cache layouts also diverge. The Xeon E-2378 provides 80 KB of L1 cache per core and 512 KB of L2 per core, while the Core i9-9900 has 64 KB L1 and 256 KB L2 per core. Both share 16 MB of L3 cache, so the total L3 capacity is identical, but the larger L1 and L2 on the Xeon likely contribute to its consistent benchmark advantage.

Memory support differs in both bandwidth and ECC capability. The Xeon E-2378 supports DDR4 memory with a dual-channel bus and a memory bandwidth of 51.2 GB/s, plus ECC memory support. The Core i9-9900 also uses dual-channel DDR4 but has a lower memory bandwidth of 42.7 GB/s and no ECC support. PCIe connectivity is another differentiator: the Xeon offers Gen 4 with 20 lanes from the CPU, while the Core i9-9900 provides Gen 3 with 16 lanes.

The Core i9-9900 includes integrated graphics (UHD Graphics 630), which the Xeon E-2378 lacks entirely. This is a significant architectural difference for users who need a display output without a separate graphics card. The Xeon also uses a different socket (Intel Socket 1200) compared to the Core i9-9900’s Intel Socket 1151, meaning they are not interchangeable in the same motherboard.

Clock speeds favor the Core i9-9900 on paper: it has a base clock of 3.10 GHz and a boost clock of 5.00 GHz, versus 2.60 GHz base and 4.80 GHz boost for the Xeon E-2378. Despite the Core i9-9900’s higher rated clocks, the Xeon’s benchmark wins suggest architectural efficiency offsets this. Both have a TDP of 65 watts, so power draw is equal, and neither has an unlocked multiplier.

FAQ

Q: Which processor has a higher boost clock?

A: The Intel Core i9-9900 has a boost clock of 5.00 GHz, which is higher than the Xeon E-2378’s 4.80 GHz.

Q: Does the Xeon E-2378 support ECC memory?

A: Yes, the Xeon E-2378 supports ECC memory, while the Core i9-9900 does not.

Q: What is the largest benchmark delta between the two?

A: The largest delta is 8.4%, seen in Cinebench R20 single-core, where the Xeon E-2378 scores 867 versus 800 for the Core i9-9900.

Q: Do both processors have the same L3 cache size?

A: Yes, both the Xeon E-2378 and the Core i9-9900 have 16 MB of shared L3 cache.

Q: Which processor has integrated graphics?

A: The Intel Core i9-9900 includes UHD Graphics 630, while the Xeon E-2378 has no integrated graphics.

Q: Are both processors on the same socket?

A: No, the Xeon E-2378 uses Intel Socket 1200, while the Core i9-9900 uses Intel Socket 1151.

Specification Differences

The following table lists only the fields where the two processors differ, based on the provided data.

| Specification | Intel Xeon E-2378 | Intel Core i9-9900 |

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

| Series | Xeon E-2300 series | null |

| Base Clock | 2.60 GHz | 3.10 GHz |

| Boost Clock | 4.80 GHz | 5.00 GHz |

| Socket | Intel Socket 1200 | Intel Socket 1151 |

| Architecture | Rocket Lake | Coffee Lake |

| Codename | Rocket Lake-E | Coffee Lake-R |

| Generation | Xeon E (Rocket Lake-E) | Core i9 (Coffee Lake Refresh) |

| Die Size | 276 mm² | 180.3 mm² |

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

| L2 Cache | 512 KB (per core) | 256 KB (per core) |

| Memory Bandwidth | 51.2 GB/s | 42.7 GB/s |

| ECC Memory | true | false |

| PCIe | Gen 4, 20 Lanes (CPU only) | Gen 3, 16 Lanes (CPU only) |

| Integrated Graphics | null | UHD Graphics 630 |

| Market Segment | Server/Workstation | Desktop |

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

| Release Date | 2021-09-07 | 2019-04-22 |

| Launch MSRP | $362 | $423 |

| Part Number | SRKN4 | SRG18 |

| Geekbench Multi-core | N/A | 8175 |

| Geekbench Single-core | N/A | 1687 |

Head-to-Head Benchmarks

The head-to-head benchmark data is remarkably consistent, with the Xeon E-2378 winning all six tests by a narrow but uniform margin. In Cinebench R15 multi-core, the Xeon scores 1474 against 1361 for the Core i9-9900, a delta of 8.3%. The single-core R15 test shows a similar pattern: 208 versus 192, also 8.3%.

Cinebench R20 results continue the trend. The multi-core test has the Xeon at 6145 and the Core i9 at 5673, an 8.3% gap. In single-core R20, the Xeon scores 867 versus 800, which is the only test showing an 8.4% delta, the largest of the entire comparison.

Cinebench R23, the most modern test in the suite, shows the same story. Multi-core scores are 14633 for the Xeon and 13509 for the Core i9, a difference of 8.3%. Single-core R23 has the Xeon at 2065 and the Core i9 at 1907, again an 8.3% margin.

The data also includes Geekbench scores only for the Core i9-9900, with 8175 multi-core and 1687 single-core. No Geekbench results are listed for the Xeon E-2378, so a direct comparison in that test is not possible from the available facts.

The Verdict

Based strictly on the benchmark data, the Intel Xeon E-2378 is the superior performer in every measured category, winning all six head-to-head tests with a consistent 8.3–8.4% advantage. For users prioritizing raw compute throughput in Cinebench-style workloads, the Xeon E-2378 is the clear choice, despite the Core i9-9900’s higher base and boost clock speeds.

However, the Core i9-9900 should not be dismissed outright. It offers integrated UHD Graphics 630, which the Xeon lacks, making it a viable option for systems without a discrete GPU. It also has a lower launch MSRP of $423 compared to the Xeon’s $362, though the Xeon is cheaper at launch, the Core i9’s integrated graphics may offset that for certain builds.

The Xeon E-2378 is the pick for server or workstation deployments where ECC memory support, higher memory bandwidth (51.2 GB/s vs 42.7 GB/s), and Gen 4 PCIe connectivity matter. The Core i9-9900, being end-of-life and limited to Gen 3 PCIe, is more suited for legacy desktop builds where a GPU is already present. The data shows no scenario where the Core i9-9900 outperforms the Xeon in the benchmarks tested, so the verdict is straightforward: the Xeon E-2378 wins on performance, while the Core i9-9900 retains value only for its integrated graphics and desktop platform compatibility.