Intel Core 3 305 vs Intel Core i5-12400 Comparison

Head-to-Head Benchmarks

The head-to-head data shows a decisive overall win for the Intel Core i5-12400, taking 13 of 17 recorded comparisons. The most dramatic gap appears in integer math, where the i5-12400 scores 58366 against 32295 for the Core 3 305, a 80.7% advantage. This is the single largest delta in the entire benchmark set. Data compression also heavily favors the i5-12400, with scores of 226908 versus 146857, a 54.5% lead. These two workloads suggest the i5-12400 has a substantial edge in raw arithmetic throughput and data handling.

The Cinebench suite tells a consistent story. Across R15, R20, and R23, the i5-12400 wins every single-core and multi-core iteration by roughly 21.8% to 22%. For example, Cinebench R23 multi-core shows 15989 for the i5-12400 against 13123 for the Core 3 305. Single-core R23 shows 2257 versus 1852. The consistency of these deltas, all hovering near 22%, points to a fundamental per-clock or per-thread advantage rather than a workload-specific quirk. PassMark multi-thread also aligns with this pattern: 18747 versus 15439, a 21.4% win for the i5-12400.

Random string sorting goes to the i5-12400 at 22366 versus 17623, a 26.9% margin. Floating-point math shows a narrower i5-12400 win, 45494 against 42284, a 7.6% edge. Extended instructions favor the i5-12400 at 15399 versus 13543, a 13.7% gap. Even data encryption, the closest multi-threaded race, goes to the i5-12400 at 11418 against 11019, a modest 3.6% difference.

The Core 3 305 does secure four wins, and they are worth examining. The most striking is PassMark find prime numbers, where the Core 3 305 scores 115 against the i5-12400's 68, a 40.9% advantage. This is a reversal of the overall trend, indicating that the Core 3 305's architecture handles this particular integer workload far more efficiently. PassMark physics also goes to the Core 3 305, 1233 versus 1105, a 10.4% win. Single-thread scores favor the Core 3 305 as well, with 3977 against 3456, a 13.1% lead in both the passmark_single_thread and passmark_singlethread entries. These single-thread results are notable because they contradict the Cinebench single-core data, where the i5-12400 leads by 22%. The two benchmark suites clearly measure different aspects of single-thread performance.

Architecture Differences

The two processors come from very different design points. The Intel Core i5-12400 is a desktop part built on Alder Lake-S architecture, fabricated on Intel's 10 nm process. It has 6 cores and 12 threads, with a base clock of 2.50 GHz and a boost clock of 4.40 GHz. The Core 3 305, by contrast, is a mobile processor codenamed Wildcat Lake, built on a 3 nm process. It also has 6 cores, but only 6 threads, with a much lower base clock of 1.50 GHz and a boost clock of 4.30 GHz. The thread count difference is critical: the i5-12400 supports simultaneous multithreading, effectively doubling its thread count, while the Core 3 305 does not.

Cache layouts diverge significantly. The i5-12400 offers 80 KB of L1 per core, 1.25 MB of L2 per core, and 18 MB of shared L3 cache. The Core 3 305 lists 192 KB of L1, 2.5 MB of L2, and 6 MB of shared L3. The i5-12400's larger L3 pool likely contributes to its multi-threaded performance in cache-sensitive workloads like data compression. The Core 3 305's smaller L3, combined with its single-channel memory bus, suggests a design focused on power efficiency rather than peak throughput.

Memory support is another major split. The i5-12400 supports DDR4 and DDR5 in a dual-channel configuration. The Core 3 305 supports DDR5 and LPDDR5X but only in a single-channel configuration, with a listed memory bandwidth of 59.7 GB/s. The i5-12400's dual-channel memory path gives it more memory bandwidth headroom, which likely explains some of its advantage in bandwidth-intensive tasks. PCIe connectivity also differs: the i5-12400 offers Gen 5 with 16 CPU lanes, while the Core 3 305 offers Gen 4 with 6 CPU lanes. The desktop part clearly has more expansion headroom.

Integrated graphics differ as well. The i5-12400 includes UHD Graphics 730, while the Core 3 305 includes Intel Xe3 Graphics with 1 Xe core. The mobile part's graphics are newer, but no benchmark data in the database covers graphics performance. The socket types reflect their target markets: the i5-12400 uses Intel Socket 1700, a desktop LGA socket, while the Core 3 305 uses Intel BGA 1516, a soldered mobile package. Power envelopes are starkly different, with the i5-12400 rated at 65 W TDP and the Core 3 305 at 15 W TDP, though the database does not provide direct power consumption measurements.

FAQ

Q: Which processor has the higher multi-core performance?

A: The Intel Core i5-12400 wins every multi-core benchmark in the head-to-head set. Cinebench R23 multi-core shows 15989 versus 13123, a 21.8% lead. PassMark multi-thread shows 18747 versus 15439, a 21.4% lead. The i5-12400 also wins data compression by 54.5% and integer math by 80.7%.

Q: Does the Core 3 305 win any benchmarks?

A: Yes, it wins 4 of 17 head-to-head tests. These are PassMark find prime numbers (115 versus 68, a 40.9% advantage), PassMark physics (1233 versus 1105, a 10.4% advantage), and both PassMark single-thread entries (3977 versus 3456, a 13.1% advantage).

Q: Why does the i5-12400 have more threads if both have 6 cores?

A: The i5-12400 supports simultaneous multithreading, giving it 12 threads from 6 cores. The Core 3 305 does not support multithreading, so it has only 6 threads. This doubles the i5-12400's thread count and contributes to its multi-core benchmark wins.

Q: What are the clock speed differences?

A: The i5-12400 has a base clock of 2.50 GHz and a boost clock of 4.40 GHz. The Core 3 305 has a base clock of 1.50 GHz and a boost clock of 4.30 GHz. The i5-12400 has a higher base clock, while the boost clocks are close, differing by only 0.10 GHz.

Q: How do the cache sizes compare?

A: The i5-12400 has 80 KB L1 per core, 1.25 MB L2 per core, and 18 MB shared L3. The Core 3 305 has 192 KB L1, 2.5 MB L2, and 6 MB shared L3. The i5-12400 has significantly more L3 cache, while the Core 3 305 has larger L1 and L2 caches.

Q: Which processor has better single-thread performance?

A: The answer depends on the benchmark. The Core 3 305 leads in PassMark single-thread tests, scoring 3977 against 3456, a 13.1% advantage. However, the i5-12400 leads in Cinebench R15, R20, and R23 single-core tests, with deltas around 22% in each case.

Specification Differences

| Specification | Intel Core i5-12400 | Intel Core 3 305 |

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

| Cores | 6 | 6 |

| Threads | 12 | 6 |

| Base Clock | 2.50 GHz | 1.50 GHz |

| Boost Clock | 4.40 GHz | 4.30 GHz |

| TDP | 65 W | 15 W |

| Socket | Intel Socket 1700 | Intel BGA 1516 |

| Process Node | 10 nm | 3 nm |

| Codename | Alder Lake-S | Wildcat Lake |

| L1 Cache | 80 KB (per core) | 192 KB |

| L2 Cache | 1.25 MB (per core) | 2.5 MB |

| L3 Cache | 18 MB (shared) | 6 MB (shared) |

| Memory Support | DDR4, DDR5 | DDR5, LPDDR5X |

| Memory Bus | Dual-channel | Single-channel |

| Memory Bandwidth | Not listed | 59.7 GB/s |

| PCIe | Gen 5, 16 Lanes (CPU only) | Gen 4, 6 Lanes (CPU only) |

| Integrated Graphics | UHD Graphics 730 | Intel Xe3 Graphics (1 Xe) |

| Market Segment | Desktop | Mobile |

| Release Date | 2022-01-03 | 2026-04-15 |

Where Each One Wins

The Intel Core i5-12400 is the clear winner for multi-threaded desktop workloads. Its 12 threads, dual-channel memory, and 18 MB of shared L3 cache give it commanding leads in integer math, data compression, and all Cinebench multi-core tests. Users who run video encoding, software compilation, or heavy spreadsheet calculations will see the i5-12400 outperform the Core 3 305 by roughly 21% to 80% in the recorded benchmarks. The i5-12400 also wins memory-bandwidth-sensitive tasks like random string sorting, where its dual-channel memory path likely matters.

The Core 3 305 wins in specific niche workloads. Its PassMark find prime numbers score is 40.9% higher, which suggests its architecture handles certain integer algorithms more efficiently despite having fewer threads. PassMark physics also goes its way, a 10.4% win. Single-thread PassMark tests favor the Core 3 305 by 13.1%, indicating that its 3 nm process and newer core design deliver better per-core performance in some workloads. However, the Cinebench single-core results contradict this, so the Core 3 305's single-thread advantage is not universal.

The Core 3 305 is also the only viable choice for mobile applications. Its 15 W TDP, BGA socket, and support for LPDDR5X memory mark it as a laptop processor. The i5-12400, with its 65 W TDP and desktop Socket 1700, is not designed for portable systems. The Core 3 305's single-channel memory bus and 6 PCIe Gen 4 lanes are consistent with a low-power mobile design, while the i5-12400's dual-channel memory and 16 PCIe Gen 5 lanes suit a desktop platform.

The Verdict

The data points to a straightforward split. For desktop users who need maximum multi-threaded performance, the Intel Core i5-12400 is the stronger processor. It wins 13 of 17 head-to-head benchmarks, with particularly large margins in integer math (80.7%), data compression (54.5%), and random string sorting (26.9%). Its 12 threads, dual-channel memory support, and 18 MB L3 cache give it a structural advantage that shows up across nearly every recorded workload. The Cinebench results are uniform: the i5-12400 leads by about 22% in every R15, R20, and R23 test, both single-core and multi-core. Its launch MSRP is $199.

For mobile systems, the Core 3 305 is the only option between the two, given its 15 W TDP and BGA 1516 socket. It also demonstrates genuine strengths. The PassMark single-thread score of 3977 beats the i5-12400's 3456 by 13.1%, and its find prime numbers result is 40.9% higher. These wins suggest that for certain single-threaded workloads, the Core 3 305's newer 3 nm process delivers better efficiency and per-core performance. Its launch MSRP is $309.

The average benchmark scores are nearly identical: 18683 for the i5-12400 and 18302 for the Core 3 305, a difference of roughly 2%. Both sit at the 72nd percentile among all CPUs in the database. The i5-12400's nearest rival is the AMD EPYC 7643 at -0.1%, while the Core 3 305's nearest rival is the Intel Core i3-14100 at -0.1%. The overall performance class is similar, but the workload profiles diverge sharply. Users who prioritize multi-threaded throughput should choose the i5-12400. Users who need a low-power mobile processor with strong single-thread PassMark results should choose the Core 3 305. The data does not support a single universal winner; it supports two different tools for two different jobs.