Intel Core i3-12100F vs Intel Core i5-8400 Comparison

Head-to-Head Benchmarks

The benchmark data shows a decisive overall victory for the Intel Core i3-12100F, which wins 17 of the 19 recorded comparisons. The margin is substantial in most workloads, but the Intel Core i5-8400 does claim two narrow wins that reveal its remaining strengths.

Starting with the most heavily threaded workloads, the i3-12100F dominates. In Cinebench R23 multi-core, it scores 11860 against the i5-8400's 7847, a 51.1% advantage. The pattern repeats in Cinebench R20 multi-core (4981 vs 3295, 51.2% ahead) and Cinebench R15 multi-core (1195 vs 790, 51.3% ahead). Geekbench multi-core shows a slightly smaller but still substantial gap: 7252 versus 5088, a 42.5% lead. PassMark's multi-thread test tells the same story, with the i3-12100F scoring 14015 against 9225, a 51.9% improvement.

Single-thread performance follows the same direction. Cinebench R23 single-core gives the i3-12100F a 1674 score versus 1107 for the i5-8400, a 51.2% delta. Cinebench R20 single-core shows 703 against 464, 51.5% ahead. Geekbench single-core records 1932 versus 1353, a 42.8% lead. PassMark single-thread data shows 3444 against 2371, 45.3% ahead. The same PassMark single-thread figure appears twice in the database, confirming the result.

Specialized workloads amplify the gap further. PassMark data encryption is the most extreme divergence: the i3-12100F scores 8071, while the i5-8400 manages only 2824, a 185.8% difference. This suggests a major architectural leap in cryptographic instruction handling. PassMark find prime numbers shows a 62.2% delta (60 vs 37), and PassMark integer math shows 40978 versus 25573, a 60.2% advantage. PassMark physics records 985 versus 635, a 55.1% lead. PassMark floating point math gives 31977 against 22006, a 45.3% margin. PassMark data compression shows 160452 versus 129951, a 23.5% edge.

The i5-8400's two wins are modest. PassMark extended instructions goes to the i5-8400 with 11543 against 10842, a 6.1% margin. PassMark random string sorting goes to the i5-8400 with 15952 versus 15809, just 0.9% ahead. These are the only benchmarks where the older chip retains any advantage, and both margins are small compared to the i3-12100F's typical leads.

The average benchmark scores reflect this overall picture. The i3-12100F averages 13494 across its recorded benchmarks, while the i5-8400 averages 12765. Both processors sit at the 68th percentile among all CPUs in the database, meaning they occupy similar overall tiers despite the i3-12100F's stronger head-to-head results. The i3-12100F's nearest rivals by average score include the Intel Core 3 N355 (13492, 0% delta), Intel Core i5-9500 (13452, 0.3% ahead), and Intel Core 5 120UL (13594, 0.7% behind). The i5-8400's nearest rivals include the Intel Xeon Gold 6348 (12746, 0.2% ahead) and AMD EPYC 7502 (12709, 0.4% behind).

Architecture Differences

The two processors come from different Intel generations with distinct design philosophies. The i3-12100F uses the Alder Lake architecture on a 10 nm process node, while the i5-8400 uses the older Coffee Lake architecture on a 14 nm node. Both are built by Intel, but the process shrink gives the newer chip a fundamental efficiency and density advantage.

Core counts differ in an interesting way. The i5-8400 has six physical cores but only six threads, meaning no hyper-threading. The i3-12100F has four physical cores but eight threads thanks to hyper-threading. This means the i3-12100F presents eight logical processors to the operating system versus six for the i5-8400, which helps explain its multi-threaded wins despite having fewer physical cores.

Clock speeds favor the i3-12100F. Its base clock is 3.30 GHz with a boost clock of 4.30 GHz. The i5-8400 sits at 2.80 GHz base and 4.00 GHz boost. The combination of higher clocks and hyper-threading drives most of the performance differences seen in the benchmarks.

Cache configurations also favor the newer part. The i3-12100F has 80 KB of L1 cache per core, 1.25 MB of L2 per core, and 12 MB of shared L3. The i5-8400 has 64 KB L1 per core, 256 KB L2 per core, and 9 MB shared L3. The larger per-core L2 and total L3 give the i3-12100F more room for frequently accessed data.

Memory support differs. The i3-12100F supports both DDR4 and DDR5, while the i5-8400 supports only DDR4. Both use dual-channel memory buses. The i5-8400 lists a memory bandwidth of 42.7 GB/s, while the i3-12100F has no recorded bandwidth figure. The i3-12100F also supports PCIe Gen 5 with 16 CPU lanes, while the i5-8400 is limited to PCIe Gen 3 with 16 CPU lanes.

The i5-8400 includes integrated UHD Graphics 630, while the i3-12100F has no integrated graphics. This is a notable trade-off: the i3-12100F requires a discrete GPU, but the i5-8400 can run with a basic display output. The i5-8400's production status is end-of-life, and its release date is recorded as 2017-10-04, while the i3-12100F remains active with no recorded release date.

Die sizes are similar: the i3-12100F measures 163 mm² and the i5-8400 measures 154 mm². Both are socketed desktop parts, with the i3-12100F on Intel Socket 1700 and the i5-8400 on Intel Socket 1151. Neither has an unlocked multiplier.

FAQ

Q: Which processor has more physical cores?

A: The Intel Core i5-8400 has six physical cores, while the Intel Core i3-12100F has four. However, the i3-12100F has eight threads versus six for the i5-8400, so the newer chip still wins most multi-threaded benchmarks.

Q: Does the i3-12100F support faster memory?

A: The i3-12100F supports both DDR4 and DDR5, while the i5-8400 supports only DDR4. Both use dual-channel memory buses. The i5-8400 has a recorded memory bandwidth of 42.7 GB/s, but the i3-12100F has no bandwidth figure in the database.

Q: Which processor is better for encryption workloads?

A: The i3-12100F is dramatically better. PassMark data encryption shows a score of 8071 versus 2824 for the i5-8400, a 185.8% advantage. This is the largest gap in any recorded benchmark.

Q: Does either processor include integrated graphics?

A: The i5-8400 includes UHD Graphics 630, while the i3-12100F has no integrated graphics. This means the i3-12100F requires a separate graphics card for display output.

Q: What is the single-thread performance difference?

A: The i3-12100F leads in every single-thread benchmark. Cinebench R23 single-core shows 1674 versus 1107, a 51.2% lead. Geekbench single-core shows 1932 versus 1353, a 42.8% lead. PassMark single-thread shows 3444 versus 2371, a 45.3% lead.

Q: Are there any workloads where the i5-8400 wins?

A: Yes, two. PassMark extended instructions goes to the i5-8400 with 11543 versus 10842, a 6.1% lead. PassMark random string sorting goes to the i5-8400 with 15952 versus 15809, a 0.9% lead. Both margins are small.

Specification Differences

| Specification | Intel Core i3-12100F | Intel Core i5-8400 |

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

| Cores | 4 | 6 |

| Threads | 8 | 6 |

| Base clock | 3.30 GHz | 2.80 GHz |

| Boost clock | 4.30 GHz | 4.00 GHz |

| TDP | 58 W | 65 W |

| Socket | Intel Socket 1700 | Intel Socket 1151 |

| Architecture | Alder Lake | Coffee Lake |

| Process node | 10 nm | 14 nm |

| Die size | 163 mm² | 154 mm² |

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

| L2 cache | 1.25 MB (per core) | 256 KB (per core) |

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

| Memory support | DDR4, DDR5 | DDR4 |

| Memory bandwidth | Not recorded | 42.7 GB/s |

| PCIe | Gen 5, 16 Lanes (CPU only) | Gen 3, 16 Lanes (CPU only) |

| Integrated graphics | None | UHD Graphics 630 |

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

| Release date | Not recorded | 2017-10-04 |

| Launch MSRP | $97 | $182 |

| Part number | SRL63 | SLAPL |

The Verdict

The recorded data points to the Intel Core i3-12100F as the stronger processor in nearly every measurable way. It wins 17 of 19 head-to-head benchmarks, with margins ranging from 23.5% to 185.8%. Its average benchmark score of 13494 exceeds the i5-8400's 12765 by about 5.7%. The i3-12100F also carries a lower launch MSRP of $97 against the i5-8400's $182, though pricing should not be the primary consideration given the performance gap.

The i5-8400 retains relevance only in two specific workloads: extended instructions and random string sorting. In both cases, its wins are narrow, and the rest of the benchmark suite shows the i3-12100F's dominance. The i5-8400's six physical cores do not compensate for its lack of hyper-threading, lower clocks, older architecture, and smaller caches.

The i3-12100F's advantages stem from a newer 10 nm process, higher clock speeds, hyper-threading, larger caches, and support for newer memory and PCIe standards. The i5-8400's integrated graphics and lower power consumption (65 W TDP versus 58 W, though the i3-12100F is actually lower) are its only notable specification-level benefits.

Users who already own an i5-8400 system on Socket 1151 may find it adequate for basic tasks, but the data shows no workload category where it substantially outperforms the i3-12100F. For new builds, the i3-12100F on Socket 1700 offers better performance across the board.

Where Each One Wins

The i3-12100F wins in all rendering workloads. Cinebench R15, R20, and R23 multi-core and single-core tests all show leads between 51.1% and 51.5%. This makes it the clear choice for content creation, 3D rendering, and any CPU-bound creative software.

The i3-12100F wins in general productivity. Geekbench multi-core and single-core tests show 42.5% and 42.8% leads respectively. PassMark integer math, floating point math, and physics tests show advantages between 45.3% and 60.2%. These results cover office work, coding, spreadsheets, and physics simulations.

The i3-12100F wins in security and encryption tasks. PassMark data encryption shows a 185.8% lead, the largest margin in the entire comparison. PassMark find prime numbers also goes to the i3-12100F by 62.2%. This makes it suitable for VPNs, disk encryption, and cryptographic operations.

The i3-12100F wins in compression and general multi-threaded workloads. PassMark data compression shows a 23.5% lead, and PassMark multithread shows a 51.9% lead. These cover file archiving, backup tasks, and parallel processing.

The i5-8400 wins in two narrow areas. PassMark extended instructions shows a 6.1% lead, which covers specialized instruction sets used in some niche scientific or legacy software. PassMark random string sorting shows a 0.9% lead, a marginal edge in sorting workloads. Neither win is large enough to recommend the i5-8400 for these tasks over the i3-12100F.

The i5-8400 also offers integrated graphics, which the i3-12100F lacks. This matters only for systems that need display output without a discrete GPU. The i5-8400's end-of-life status and older Socket 1151 platform limit its future upgrade path, while the i3-12100F remains active on the current Socket 1700 platform.