Intel Core i5-1230U vs Intel Core i5-8400 Comparison

The Intel Core i5-8400 and Intel Core i5-1230U represent two very different design philosophies from Intel, separated by roughly four years of architectural evolution. The i5-8400 is a desktop Coffee Lake part, built on a 14 nm process with 6 cores and 6 threads, while the i5-1230U is a mobile Alder Lake-U chip, using a 10 nm node and a hybrid layout of 10 cores and 12 threads. The benchmark data shows a clear split: the i5-1230U wins the majority of head-to-head tests (13 vs. 6), but the i5-8400 takes decisive victories in specific multi-core and extended instruction workloads. The i5-1230U’s overall percentile rank (67) is just one point below the i5-8400’s 68, yet their average benchmark scores differ by only 206 points (12,765 vs. 12,559). This is a collision of desktop power and mobile efficiency, where each processor dominates in its native environment.

Where Each One Wins

The Core i5-8400 is the clear champion in heavy multi-core rendering and specialized instruction workloads. Its biggest win comes in Cinebench R23 multi-core, where it scores 7,847 against the i5-1230U’s 4,402, a massive 78.3% advantage. It also wins Cinebench R15 multi-core (790 vs. 514, +53.7%), Geekbench multi-core (5,088 vs. 4,875, +4.4%), PassMark extended instructions (11,543 vs. 6,282, +83.7%), PassMark data compression (129,951 vs. 114,042, +14%), and PassMark random string sorting (15,952 vs. 12,760, +25%). These results indicate that the i5-8400 is better suited for sustained, all-core workloads like video encoding, 3D rendering, and heavy data processing that can utilize its 6 full-performance cores and 9 MB of shared L3 cache.

The Core i5-1230U, conversely, sweeps single-threaded performance and a wide range of integer and encryption tasks. It wins Cinebench R23 single-core (1,310 vs. 1,107, +15.5%), Cinebench R20 single-core (550 vs. 464, +15.6%), Geekbench single-core (1,699 vs. 1,353, +20.4%), and PassMark single-thread (2,712 vs. 2,371, +12.6%). Its most striking victories are in PassMark integer math (38,401 vs. 25,573, +33.4%) and data encryption (7,176 vs. 2,824, +60.6%). The i5-1230U also wins multi-threaded synthetic tests like PassMark multithread (10,881 vs. 9,225, +15.2%) and Cinebench R20 multi-core (3,903 vs. 3,295, +15.6%), despite losing the R15 and R23 multi-core tests. This suggests the 1230U’s hybrid architecture—combining performance and efficiency cores—excels in short bursts and mixed workloads typical of mobile computing.

FAQ

Q: Which processor has a higher single-core score in Geekbench?

A: The Intel Core i5-1230U leads with a score of 1,699, compared to the Core i5-8400’s 1,353. This represents a 20.4% advantage for the mobile chip.

Q: How large is the multi-core gap in Cinebench R23?

A: The Core i5-8400 wins decisively with 7,847 points versus 4,402 for the i5-1230U, a delta of 78.3%. This is the largest single benchmark margin in the head-to-head data.

Q: Does the i5-1230U win any multi-core tests?

A: Yes, the i5-1230U wins Cinebench R20 multi-core (3,903 vs. 3,295, +15.6%) and PassMark multithread (10,881 vs. 9,225, +15.2%), but it loses both Cinebench R15 and R23 multi-core tests.

Q: What is the average benchmark score difference between the two?

A: The i5-8400 has an average benchmark score of 12,765, while the i5-1230U scores 12,559. That is a difference of only 206 points, or roughly 1.6%.

Q: Which CPU performs better in PassMark data encryption?

A: The Core i5-1230U is vastly superior, scoring 7,176 versus 2,824 for the i5-8400. That is a 60.6% lead for the mobile processor.

Q: How do their overall percentile rankings compare?

A: The i5-8400 sits at the 68th percentile of all CPUs, while the i5-1230U is at the 67th percentile. Despite the different designs, they are nearly identical in overall standing.

Head-to-Head Benchmarks

The most lopsided results favor the i5-8400 in instruction-heavy workloads. In PassMark extended instructions, the i5-8400 scores 11,543 against the i5-1230U’s 6,282, a staggering 83.7% delta. Cinebench R23 multi-core follows suit with a 78.3% lead (7,847 vs. 4,402). The i5-8400 also dominates Cinebench R15 multi-core (790 vs. 514, +53.7%) and PassMark random string sorting (15,952 vs. 12,760, +25%). These are all scenarios where the i5-8400’s higher TDP (65 watts) and consistent power delivery allow it to sustain high clock speeds across all six cores.

The i5-1230U’s biggest win is in PassMark data encryption, where it nearly triples the i5-8400’s output: 7,176 vs. 2,824, a 60.6% delta. It also demonstrates strong integer performance, scoring 38,401 in PassMark integer math versus 25,573 for the i5-8400 (+33.4%). In Cinebench R15 single-core, the i5-1230U scores 186.8 versus 111 for the i5-8400, a 40.6% lead that highlights the architectural leap in per-core efficiency. The i5-1230U also wins PassMark find prime numbers (55 vs. 37, +32.7%), PassMark physics (828 vs. 635, +23.3%), and Geekbench single-core (1,699 vs. 1,353, +20.4%).

The intermediate results show a mixed bag. In PassMark floating point math, the i5-1230U wins 25,340 vs. 22,006 (+13.2%). PassMark multithread goes to the i5-1230U at 10,881 vs. 9,225 (+15.2%). Cinebench R20 multi-core favors the i5-1230U at 3,903 vs. 3,295 (+15.6%), while Geekbench multi-core narrowly goes to the i5-8400 at 5,088 vs. 4,875 (+4.4%). The i5-1230U also takes Cinebench R20 single-core (550 vs. 464, +15.6%) and both PassMark single-thread entries (2,712 vs. 2,371, +12.6%). These results suggest that the i5-1230U’s boost clock of 4.40 GHz gives it a significant edge in bursty single-thread tasks, but the i5-8400’s sustained all-core performance wins out in longer rendering workloads.

Specification Differences

The two processors differ fundamentally in their physical and power characteristics. The i5-8400 is a desktop chip with a TDP of 65 watts, while the i5-1230U is a mobile part with a TDP of just 9 watts. The i5-8400 uses Intel Socket 1151, whereas the i5-1230U uses Intel BGA 1781, indicating it is soldered to the motherboard. The i5-8400 has 6 cores and 6 threads, while the i5-1230U has 10 cores and 12 threads. Base clocks diverge wildly: the i5-8400 runs at 2.80 GHz, while the i5-1230U’s base clock is listed as 1000.00 MHz (likely representing a low-power base for its efficiency cores). Boost clocks are closer, with the i5-8400 at 4.00 GHz and the i5-1230U at 4.40 GHz.

Cache configurations also differ. The i5-8400 has 64 KB of L1 cache per core, 256 KB of L2 per core, and 9 MB of shared L3. The i5-1230U has 80 KB of L1 per core, 1.25 MB of L2 per core, and 12 MB of shared L3. Memory support diverges: the i5-8400 supports only DDR4 with dual-channel memory and a bandwidth of 42.7 GB/s, while the i5-1230U supports both DDR4 and DDR5 with dual-channel memory (bandwidth not specified). PCIe capability differs as well: the i5-8400 offers Gen 3 with 16 lanes (CPU only), while the i5-1230U offers Gen 4. Integrated graphics are different, with the i5-8400 using UHD Graphics 630 and the i5-1230U using Iris Xe 80EU. The i5-8400 has a launch MSRP of $182, while the i5-1230U has no listed launch MSRP. Production status also differs: the i5-8400 is end-of-life, while the i5-1230U is active.

Architecture Differences

Architecturally, these are two distinct generations of Intel silicon. The i5-8400 is based on Coffee Lake, a refinement of the Skylake architecture, built on Intel’s 14 nm process node. It is a monolithic design with six identical cores, each running at the same clock speeds, and a 154 mm² die size. The i5-1230U, by contrast, is Alder Lake-U, a hybrid architecture that mixes performance cores and efficiency cores on Intel’s 10 nm process. This allows it to achieve a higher thread count (12) with fewer physical resources, while also enabling much lower power consumption (9 watts vs. 65 watts). The i5-1230U’s cache hierarchy is more generous per core, with 1.25 MB of L2 per core versus 256 KB on the i5-8400, and its L3 cache is 12 MB versus 9 MB. The i5-1230U also supports newer memory standards (DDR5) and PCIe Gen 4, while the i5-8400 is limited to DDR4 and PCIe Gen 3. The integrated graphics on the i5-1230U (Iris Xe 80EU) represent a much newer GPU architecture than the UHD Graphics 630 on the i5-8400. These architectural differences explain the benchmark split: the i5-1230U leverages its newer process and hybrid design for superior single-thread and efficiency-oriented tasks, while the i5-8400 relies on its higher TDP and consistent all-core performance to dominate in multi-threaded rendering and instruction-heavy workloads. The i5-8400’s release date is 2017-10-04, while the i5-1230U was released on 2022-02-22, showing over four years of process and design evolution between the two.