Intel Core i3-N305 vs Intel Core i5-8400T Comparison

Head-to-Head Benchmarks

The head-to-head data reveals a clear split between these two processors, with the Intel Core i3-N305 winning five of the eight recorded comparisons, while the Intel Core i5-8400T takes three. The most dramatic difference appears in Cinebench R15 single-core, where the i3-N305 posts a score of 164.7 against the i5-8400T's 89, a 46% advantage. That is the largest gap in either direction across all tests. The same pattern holds in Cinebench R20 single-core, where the i3-N305 leads by 21.2% with a score of 472 versus 372. In Cinebench R23 single-core, the i3-N305 again wins, scoring 995 against 886, an 11% margin.

The multi-core results are more nuanced. In Cinebench R15 multi-core, the i3-N305 scores 829 versus 633, a 23.6% win. In Cinebench R20 multi-core, it leads 3349 to 2638, another 21.2% margin. However, the i5-8400T strikes back decisively in Cinebench R23 multi-core, scoring 6282 against the i3-N305's 5092, a 23.4% advantage. This reversal is noteworthy because the R23 workload is the most demanding in the recorded set, and it suggests that sustained multi-threaded performance favors the older desktop chip.

Geekbench results favor the i5-8400T in both single and multi-core tests. In Geekbench multi-core, the i5-8400T scores 4011 versus 3881, a 3.3% lead. In Geekbench single-core, it scores 1100 versus 1049, a 4.9% margin. These are modest but consistent wins. The overall benchmark averages tell a similar story: the i5-8400T has an average score of 2001 across all tests, while the i3-N305 averages 1979. The i5-8400T sits at the 45th percentile of all CPUs, and the i3-N305 at the 44th, so they land within one percentile point of each other in the broader database.

The i3-N305's wins are concentrated in the Cinebench R15 and R20 suites, both single and multi-core, plus R23 single-core. The i5-8400T's wins come in R23 multi-core and both Geekbench tests. This distribution implies the i3-N305 has an edge in short, bursty workloads, while the i5-8400T holds up better in longer multi-threaded rendering tasks and in the Geekbench suite.

Architecture Differences

The two chips come from different eras and design philosophies. The i5-8400T is built on Coffee Lake, a 14 nm process, and belongs to the Core i5 generation. It has 6 cores and 6 threads, with a base clock of 1700 MHz and a boost clock of 3.30 GHz. The i3-N305 uses Gracemont architecture, a 10 nm process, and belongs to the Core i3 Alder Lake-N generation. It has 8 cores and 8 threads, with a base clock of 100 MHz and a boost clock of 3.80 GHz. The i3-N305's base clock is unusually low, which suggests it relies heavily on boosting to reach its operating frequencies.

Cache configurations differ substantially. The i5-8400T has 64 KB of L1 per core, 256 KB of L2 per core, and 9 MB of shared L3 cache. The i3-N305 has 96 KB of L1 per core, 2 MB of L2 per module, and 6 MB of shared L3 cache. The i5-8400T's larger L3 pool is notable, since it has fewer cores but more shared cache. The i3-N305's L2 is organized per module rather than per core, reflecting its Gracemont design.

The i5-8400T uses an Intel Socket 1151 and is a desktop part, while the i3-N305 uses Intel BGA 1264 and is a mobile part. The i5-8400T has a 35 W TDP, while the i3-N305 has a 15 W TDP, so the mobile chip draws less power despite having more cores. The i5-8400T supports dual-channel DDR4 memory with a bandwidth of 42.7 GB/s. The i3-N305 supports both DDR4 and DDR5, but only in single-channel mode, with a bandwidth of 38.4 GB/s. This is a meaningful difference: the older desktop chip has a wider memory path, while the newer mobile chip has less memory bandwidth but supports newer memory types.

PCIe connectivity also differs. The i5-8400T provides Gen 3 with 16 lanes (CPU only), while the i3-N305 provides Gen 3 with 9 lanes (CPU only). The i5-8400T has more available lanes for expansion. Integrated graphics are different as well: the i5-8400T includes UHD Graphics 630, while the i3-N305 includes UHD Graphics 770. The i5-8400T was released in 2018 and is end-of-life, while the i3-N305 was released in 2023 and is still active. Neither chip supports ECC memory, and both have locked multipliers.

FAQ

Q: Which processor has better single-core performance in Cinebench R23?

A: The Intel Core i3-N305 wins in Cinebench R23 single-core, scoring 995 against the i5-8400T's 886, an 11% advantage.

Q: Why does the i5-8400T win in Cinebench R23 multi-core despite losing the R15 and R20 multi-core tests?

A: The i5-8400T scores 6282 in R23 multi-core versus 5092 for the i3-N305, a 23.4% margin. This suggests the i5-8400T sustains performance better under the longer, more demanding R23 workload, while the i3-N305's lead in R15 and R20 may reflect its ability to boost aggressively in shorter runs.

Q: How do the two chips compare in Geekbench?

A: The i5-8400T leads in both Geekbench tests. It scores 4011 in multi-core versus 3881 for the i3-N305, a 3.3% win, and 1100 in single-core versus 1049, a 4.9% win.

Q: What is the overall average benchmark score for each processor?

A: The i5-8400T has an average benchmark score of 2001, while the i3-N305 averages 1979. The i5-8400T sits at the 45th percentile of all CPUs, and the i3-N305 at the 44th.

Q: Does the i3-N305 support newer memory types?

A: Yes, the i3-N305 supports both DDR4 and DDR5, but it operates in single-channel mode with a bandwidth of 38.4 GB/s. The i5-8400T supports only DDR4 in dual-channel mode with a higher bandwidth of 42.7 GB/s.

Q: Which chip has more cores and which has a higher boost clock?

A: The i3-N305 has 8 cores and 8 threads, while the i5-8400T has 6 cores and 6 threads. The i3-N305 also has a higher boost clock of 3.80 GHz versus 3.30 GHz for the i5-8400T.

The Verdict

The recorded data points to a split decision. The Intel Core i3-N305 wins the majority of head-to-head tests, taking five of eight, and it dominates in Cinebench R15 and R20 across both single and multi-core. Its single-core advantage is substantial in R15, where it leads by 46%, and it also wins R20 single-core by 21.2% and R23 single-core by 11%. For users prioritizing short, single-threaded responsiveness, the i3-N305 is the clear choice based on these results.

The i5-8400T, however, wins the most demanding multi-core test in the set, Cinebench R23 multi-core, by 23.4%. It also wins both Geekbench tests, though by smaller margins of 3.3% and 4.9%. Its average benchmark score of 2001 is slightly higher than the i3-N305's 1979, and it sits one percentile point higher in the database. The i5-8400T also offers dual-channel memory with higher bandwidth (42.7 GB/s versus 38.4 GB/s) and 16 PCIe lanes versus 9, which may matter for systems with more expansion needs.

The i3-N305 is a mobile chip with a 15 W TDP and an active production status, while the i5-8400T is a desktop chip with a 35 W TDP and end-of-life status. The i3-N305 has more cores and a higher boost clock, but the i5-8400T has a larger shared L3 cache and a wider memory bus. The verdict from the data is that the i3-N305 is the better all-around performer in the Cinebench R15 and R20 suites, while the i5-8400T is the stronger choice for sustained multi-threaded rendering and Geekbench workloads.

Specification Differences

| Field | Intel Core i5-8400T | Intel Core i3-N305 |

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

| Cores | 6 | 8 |

| Threads | 6 | 8 |

| Base Clock | 1700.00 MHz | 100.00 MHz |

| Boost Clock | 3.30 GHz | 3.80 GHz |

| TDP | 35 W | 15 W |

| Socket | Intel Socket 1151 | Intel BGA 1264 |

| Architecture | Coffee Lake | Gracemont |

| Codename | Coffee Lake | Gracemont |

| Generation | Core i5 (Coffee Lake) | Core i3 (Alder Lake-N) |

| Process Node | 14 nm | 10 nm |

| Die Size | 154 mm² | null |

| L1 Cache | 64 KB (per core) | 96 KB (per core) |

| L2 Cache | 256 KB (per core) | 2 MB (per module) |

| L3 Cache | 9 MB (shared) | 6 MB (shared) |

| Memory Support | DDR4 | DDR4, DDR5 |

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

| Memory Bandwidth | 42.7 GB/s | 38.4 GB/s |

| PCIe | Gen 3, 16 Lanes (CPU only) | Gen 3, 9 Lanes (CPU only) |

| Integrated Graphics | UHD Graphics 630 | UHD Graphics 770 |

| Market Segment | Desktop | Mobile |

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

| Release Date | 2018-04-01 | 2023-01-02 |

| Launch MSRP | $182 | $309 |

| Part Number | SR3X6 | SRMDQ |

Where Each One Wins

The i3-N305 is the winner in five of the eight recorded benchmarks, so its strengths are broad. It wins every Cinebench R15 and R20 test, plus R23 single-core. The 46% margin in R15 single-core is the standout result, indicating a large advantage in lightly threaded, short-duration tasks. Its 23.6% win in R15 multi-core and 21.2% wins in both R20 tests reinforce the pattern: the i3-N305 excels in the older Cinebench workloads, likely due to its 8 cores and higher 3.80 GHz boost clock. The 15 W TDP also makes it a more power-efficient option for mobile systems.

The i5-8400T takes the remaining three wins. Its 23.4% victory in Cinebench R23 multi-core is the most significant, as R23 is the most demanding multi-threaded test in the set. This suggests the i5-8400T can maintain performance over longer rendering workloads, possibly aided by its 9 MB of shared L3 cache and dual-channel memory. Its Geekbench wins are modest, 3.3% in multi-core and 4.9% in single-core, but they are consistent. The i5-8400T also has a slightly higher average benchmark score (2001 versus 1979) and sits at the 45th percentile versus the 44th for the i3-N305.

For users who run shorter, bursty workloads or need a low-power mobile chip, the i3-N305 is the data-backed pick. For users who prioritize sustained multi-threaded rendering, as represented by Cinebench R23 multi-core, or who need the wider memory bus and more PCIe lanes, the i5-8400T is the stronger choice. The i5-8400T is end-of-life and a desktop part, while the i3-N305 is active and mobile, so platform considerations also factor into the decision. The data shows two chips with different strengths, and the right choice depends on which workloads matter more.