Intel Core i5-10400 vs Intel Core i5-9600K Comparison

Where Each One Wins

The benchmark split between these two six-core Intel parts is unusually clean. The Intel Core i5-9600K takes 13 of the 19 recorded head-to-head comparisons, while the Intel Core i5-10400 wins 6. The pattern is not random: the 9600K dominates in single-threaded and lightly threaded workloads, while the 10400 takes over in heavily threaded, data-intensive tasks.

The 9600K is the pick for raw responsiveness and legacy software that runs on a few threads. It wins every Cinebench round, both single-core and multi-core, across R15, R20, and R23. It also wins Geekbench single-core by a massive 40.7% margin, Geekbench multi-core by 26.8%, and PassMark single-thread by 6.5%. In PassMark physics, a test that often reflects real-time simulation and game physics, the 9600K leads by 11.5%. For prime number discovery, a classic single-thread limited stressor, it posts a 26.5% advantage.

The 10400, in contrast, is the throughput specialist. Its 12 threads versus 6 give it a clear edge in PassMark multithread (11.4% ahead), integer math (30% ahead), data compression (20.6% ahead), and random string sorting (21.1% ahead). Data encryption also favors the 10400 by 19.8%, and floating-point math lands on its side by 4.5%. If the workload scales with core count and involves large blocks of parallel integer or compression work, the 10400 is the faster chip.

The extended instruction test favors the 9600K by a modest 3.3%, suggesting that the older Coffee Lake core still holds a slight edge in SIMD-heavy code that does not scale across many threads. The overall average benchmark score, however, is close: the 9600K sits at 14605, the 10400 at 14037. That is a 4% gap in aggregate, but the distribution of wins tells the real story: pick the 9600K for speed on few threads, pick the 10400 for sustained parallel throughput.

Architecture Differences

Both processors are built on Intel's 14 nm process and use the same Skylake-derived core family, but they belong to different generations and platforms. The 9600K is Coffee Lake, released in the Core i5 Coffee Lake Refresh generation, and mounts on Intel Socket 1151. The 10400 is Comet Lake, part of the Core 10th Gen family, and uses Intel Socket 1200. That socket change means the two chips are not interchangeable in the same motherboard.

The most important architectural difference is threading. The 9600K has 6 cores and 6 threads, while the 10400 has 6 cores and 12 threads. Hyper-Threading on the 10400 effectively doubles its logical core count, which explains its wins in parallel workloads despite lower clock speeds. The 9600K compensates with a higher base clock of 3.70 GHz and boost clock of 4.60 GHz, versus 2.90 GHz and 4.30 GHz for the 10400. The 9600K also has an unlocked multiplier, allowing manual overclocking; the 10400 is locked.

Cache configuration also differs. Both share 64 KB of L1 and 256 KB of L2 per core, but the 9600K has 9 MB of shared L3 while the 10400 has 12 MB. That extra 3 MB of L3 helps the 10400 in data-heavy workloads, though the 9600K's higher clocks keep it ahead in latency-sensitive tasks. Memory support is identical: DDR4 on a dual-channel bus with 42.7 GB/s bandwidth, and no ECC support on either. Both integrate the same UHD 630 graphics (the 10400 lists it as UHD Graphics 630), and both expose PCIe Gen 3 with 16 CPU lanes.

The 9600K is end-of-life in production status, while the 10400 remains active. The 9600K draws 95 W TDP versus 65 W for the 10400. That is a notable efficiency gap, but the 9600K's higher power budget is clearly used for its clock advantage.

Head-to-Head Benchmarks

The Cinebench sweep is the 9600K's strongest showing. In Cinebench R15 multi-core, it scores 912 against 838, a 8.8% lead. Single-core R15 is 128 versus 118, an 8.5% margin. R20 multi-core repeats the pattern: 3803 versus 3492, up 8.9%; single-core R20 is 536 versus 493, up 8.7%. R23 multi-core sees 9055 versus 8316, another 8.9% gap, and R23 single-core is 1278 versus 1174, again 8.9%. The consistency across Cinebench versions suggests a fixed clock and IPC advantage, not a workload fluke.

Geekbench is where the 9600K stretches further. Multi-core: 6075 versus 4790, a 26.8% blowout. Single-core: 1559 versus 1108, a 40.7% gap. Those are the two largest deltas in the entire comparison and far exceed what clock speed alone would predict. The 10400's lower base and boost clocks, combined with Hyper-Threading overhead in a lightly threaded test, likely account for the single-core deficit. The multi-core result is surprising given the 10400's extra threads, but the 9600K's raw single-thread speed evidently wins out in this benchmark.

The 10400 answers in PassMark. Integer math is its biggest win: 41715 versus 29215, a 30% margin. Random string sorting goes to the 10400 by 21.1% (23206 versus 18313). Data compression favors the 10400 by 20.6% (187207 versus 148639). Data encryption is 19.8% better (4078 versus 3269). Floating-point math is closer, 26080 versus 24913, a 4.5% edge. PassMark multithread shows a 11.4% lead for the 10400 (12006 versus 10636). These results track the thread count advantage directly.

The 9600K's remaining wins are smaller but consistent. PassMark single-thread: 2727 versus 2560, up 6.5%. PassMark physics: 746 versus 669, up 11.5%. Prime numbers: 43 versus 34, up 26.5%. Extended instructions: 12914 versus 12501, up 3.3%. The physics and prime number wins are notable because both tests are notoriously single-thread bound, reinforcing the 9600K's clock advantage.

Specification Differences

| Specification | Intel Core i5-9600K | Intel Core i5-10400 |

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

| Cores | 6 | 6 |

| Threads | 6 | 12 |

| Base clock | 3.70 GHz | 2.90 GHz |

| Boost clock | 4.60 GHz | 4.30 GHz |

| TDP | 95 W | 65 W |

| Socket | Intel Socket 1151 | Intel Socket 1200 |

| Architecture | Coffee Lake | Comet Lake |

| Generation | Core i5 (Coffee Lake Refresh) | Core i5 (Comet Lake) |

| Process node | 14 nm | 14 nm |

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

| Multiplier unlocked | Yes | No |

| Production status | End-of-life | Active |

| Release date | 2018-10-18 | 2020-04-29 |

| Part number | SR3WZ | SRH3CSRH78 |

The process node, memory support, memory bus, memory bandwidth, PCIe configuration, integrated graphics, and ECC support are identical. The differences above are the complete set of distinguishing fields.

FAQ

Q: Which CPU has higher clock speeds?

A: The Intel Core i5-9600K runs at 3.70 GHz base and 4.60 GHz boost, compared to 2.90 GHz base and 4.30 GHz boost for the Intel Core i5-10400.

Q: Does Hyper-Threading make the 10400 faster in all multi-threaded tests?

A: No. The 10400 wins most PassMark parallel tests, but the 9600K still wins Cinebench R15, R20, and R23 multi-core tests by 8.8% to 8.9%, as well as Geekbench multi-core by 26.8%. Higher clocks and the 9600K's unlocked multiplier can offset the thread deficit in some workloads.

Q: Are these CPUs compatible with the same motherboard?

A: No. The 9600K uses Intel Socket 1151, while the 10400 uses Intel Socket 1200. They require different platforms.

Q: Which chip has more L3 cache?

A: The 10400 has 12 MB of shared L3 cache, while the 9600K has 9 MB. Both have 64 KB of L1 and 256 KB of L2 per core.

Q: Can the 10400 be overclocked?

A: No. The 10400 has a locked multiplier. The 9600K has an unlocked multiplier, so it can be overclocked manually.

Q: What is the largest single benchmark gap between the two?

A: Geekbench single-core: the 9600K scores 1559 versus 1108 for the 10400, a 40.7% difference. The next largest is the 30% lead for the 10400 in PassMark integer math.