Intel Core i5-9400 vs Intel Core i7-10710U Comparison

The benchmark data is unambiguous: the mobile Intel Core i7-10710U decisively outperforms the desktop Intel Core i5-9400 across every single-core and multi-core test in the comparison suite, winning all six head-to-head matchups. Despite the i5-9400 being a desktop part with a much higher thermal envelope, the i7-10710U's superior thread count and higher boost clock give it a consistent 14.5% to 14.8% advantage in Cinebench testing. This places them at nearly identical overall performance percentiles (both at the 47th percentile vs. all CPUs), but the i7-10710U achieves that standing with far more efficiency and in a mobile form factor.

Head-to-Head Benchmarks

The most striking pattern in the head-to-head results is the uniformity of the i7-10710U's victory margin. In Cinebench R15 multi-core, the i7-10710U scores 783 against the i5-9400's 668, a 14.7% lead. The single-core R15 test tells the same story: 110 vs 94, a 14.5% advantage. Moving to Cinebench R20, the i7-10710U posts 3265 multi-core and 460 single-core, while the i5-9400 manages 2784 and 392 respectively — again a 14.7% and 14.8% gap. The R23 results follow the identical trend: 7774 vs 6629 in multi-core and 1097 vs 935 in single-core, with the i7-10710U leading by 14.7% and 14.8%.

These are not marginal wins; they represent a clear performance tier separation. The i7-10710U's 12 threads versus the i5-9400's 6 threads explain the multi-core advantage, but the single-core wins are more revealing. A 14.5% single-core lead in R15 suggests the i7-10710U's 4.70 GHz boost clock is translating into real-world responsiveness that the i5-9400's 4.10 GHz boost cannot match, even though both CPUs share the same 14 nm process node and Intel foundry.

The average benchmark scores corroborate the head-to-head data. The i5-9400 averages 2254 across its benchmark suite, while the i7-10710U averages 2248. This near-identical average (a 0.3% difference in the i5-9400's favor) might seem contradictory to the Cinebench results, but it reflects the fact that the i5-9400's Geekbench scores (5141 multi-core, 1389 single-core) are not part of the head-to-head comparison, which only includes Cinebench tests. In the tests where both CPUs were measured, the i7-10710U wins every time by a substantial margin.

Architecture Differences

The architectural divide is fundamental. The i5-9400 is a Coffee Lake desktop processor on the Intel Socket 1151 platform, built for a 65 W TDP. It features 6 cores and 6 threads, with a base clock of 2.90 GHz and a boost of 4.10 GHz. Its cache hierarchy includes 64 KB L1 per core, 256 KB L2 per core, and 9 MB of shared L3. It supports DDR4 memory in dual-channel configuration with 42.7 GB/s bandwidth, and offers PCIe Gen 3 with 16 lanes from the CPU.

The i7-10710U is a Comet Lake-U mobile processor on the Intel BGA 1440 socket, with a drastically lower 25 W TDP. It also has 6 cores but doubles the thread count to 12 via Hyper-Threading. Its base clock is listed at 1100.00 MHz, which is exceptionally low, but its boost clock reaches 4.70 GHz — significantly higher than the i5-9400. The cache is larger: 12 MB of shared L3 versus 9 MB, with identical per-core L1 and L2 sizes. Memory support includes both DDR3 and DDR4, though the memory bus and bandwidth are not specified in the data. The i7-10710U has no listed PCIe lanes, and its integrated graphics are labeled simply as "UHD Graphics" versus the i5-9400's "UHD 630."

Both CPUs are end-of-life products, share the same 14 nm process node, and use Intel as the foundry. Neither supports ECC memory, and neither has an unlocked multiplier. The release dates differ: the i5-9400 launched on 2018-10-18, while the i7-10710U followed on 2019-08-20. The market segments are distinct — one is explicitly Desktop, the other Mobile — which explains the socket, TDP, and memory differences.

The Verdict

From the data alone, the i7-10710U is the superior processor in every measured benchmark. It wins all six head-to-head Cinebench tests with a consistent 14.5% to 14.8% margin. For users prioritizing raw compute performance in the tested workloads, the i7-10710U is the clear choice. Its 12 threads and higher boost clock deliver measurable gains in both multi-threaded and single-threaded scenarios.

However, the i5-9400 is not without merit. It offers a desktop platform with a 65 W TDP, dual-channel DDR4 memory support, and 16 PCIe Gen 3 lanes — features that matter for system builders who need expandability and memory bandwidth. The i5-9400 also has a higher base clock (2.90 GHz vs 1100.00 MHz), which could translate to better sustained performance in workloads that do not trigger boost behavior, though the benchmark data does not directly test this scenario.

The near-identical average benchmark scores (2254 vs 2248) and equal 47th percentile ranking suggest that in a broader performance context, these CPUs are peers. The i7-10710U's wins are concentrated in Cinebench, while the i5-9400's Geekbench scores (5141 multi-core, 1389 single-core) are not part of the head-to-head comparison. The verdict is straightforward: if Cinebench-style rendering workloads are the priority, the i7-10710U wins decisively. If platform features like desktop memory bandwidth and PCIe lanes matter more, the i5-9400 has structural advantages that the benchmark suite does not capture.

FAQ

Q: Which CPU wins in multi-core performance?

A: The Intel Core i7-10710U wins all three multi-core Cinebench tests (R15, R20, R23) with scores of 783, 3265, and 7774, respectively, against the i5-9400's 668, 2784, and 6629. The margin is 14.7% in each test.

Q: Is the single-core performance gap the same as multi-core?

A: Yes, the single-core gap is nearly identical. The i7-10710U leads by 14.5% in Cinebench R15 single-core (110 vs 94) and 14.8% in both R20 single-core (460 vs 392) and R23 single-core (1097 vs 935).

Q: Do these CPUs have the same number of cores?

A: Yes, both have 6 physical cores. However, the i7-10710U supports 12 threads via Hyper-Threading, while the i5-9400 has only 6 threads.

Q: What are the TDP differences?

A: The i5-9400 has a 65 W TDP for desktop use, while the i7-10710U has a 25 W TDP for mobile applications. The i7-10710U achieves higher benchmark scores despite the lower power envelope.

Q: How do their average benchmark scores compare?

A: The i5-9400 has an average benchmark score of 2254, and the i7-10710U has 2248. The i5-9400 is 0.3% ahead in this metric, and the i7-10710U is 0.1% ahead of the AMD Ryzen 5 PRO 1500, which sits between them.

Q: Which CPU has more L3 cache?

A: The i7-10710U has 12 MB of shared L3 cache, compared to the i5-9400's 9 MB. Both have 64 KB of L1 and 256 KB of L2 per core.

Where Each One Wins

The i7-10710U wins in every benchmark category measured in the head-to-head comparison. This includes all Cinebench R15, R20, and R23 tests, both single-core and multi-core. The data shows a 14.5% to 14.8% advantage across the board, making it the superior choice for rendering workloads, video encoding, or any application that scales with CPU compute performance. Its 12 threads and 4.70 GHz boost clock are the likely drivers of this dominance.

The i5-9400 does not win any head-to-head benchmarks, but its specification sheet reveals areas where it could be preferable. It supports dual-channel DDR4 memory with 42.7 GB/s bandwidth, a feature the i7-10710U lacks in the data (memory bus and bandwidth are not listed). It also provides 16 PCIe Gen 3 lanes from the CPU, which the i7-10710U does not specify. For a desktop builder needing a discrete GPU and fast NVMe storage, the i5-9400's platform connectivity is a tangible advantage. Its higher base clock of 2.90 GHz versus the i7-10710U's 1100.00 MHz could also mean better performance in lightly threaded tasks that run at base clocks rather than boost.

The i7-10710U is the winner for pure compute. The i5-9400 is the winner for platform flexibility in a desktop build. The data does not show the i5-9400 winning any performance test, but its memory and PCIe specifications give it a structural edge that benchmarks in this comparison do not capture.

Specification Differences

| Specification | Intel Core i5-9400 | Intel Core i7-10710U |

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

| Threads | 6 | 12 |

| Base Clock | 2.90 GHz | 1100.00 MHz |

| Boost Clock | 4.10 GHz | 4.70 GHz |

| TDP | 65 W | 25 W |

| Socket | Intel Socket 1151 | Intel BGA 1440 |

| Architecture | Coffee Lake | Comet Lake |

| Codename | Coffee Lake | Comet Lake-U |

| Generation | Core i5 (Coffee Lake Refresh) | Core i7 (Comet Lake-U) |

| L3 Cache | 9 MB (shared) | 12 MB (shared) |

| Memory Support | DDR4 | DDR3, DDR4 |

| Memory Bus | Dual-channel | Not specified |

| Memory Bandwidth | 42.7 GB/s | Not specified |

| PCIe | Gen 3, 16 Lanes (CPU only) | Not specified |

| Integrated Graphics | UHD 630 | UHD Graphics |

| Market Segment | Desktop | Mobile |

| Release Date | 2018-10-18 | 2019-08-20 |

| Part Number | SR3X5 | Not specified |

The two CPUs share several core attributes: 6 cores, 14 nm process node, Intel foundry, 64 KB L1 per core, 256 KB L2 per core, no ECC support, no unlocked multiplier, and end-of-life production status. Their differences are concentrated in thread count, clock speeds, power envelope, socket, cache size, memory capabilities, and platform positioning.