Intel Core 3 N355 vs Intel Core i5-8400 Comparison

FAQ

Q: How do the two processors compare in overall average benchmark score?

A: The Intel Core 3 N355 records an average benchmark score of 13492, while the Intel Core i5-8400 sits at 12765. The N355 also holds a 68th percentile ranking versus all CPUs, matching the i5-8400's 68th percentile placement.

Q: Which processor wins more head-to-head benchmark tests?

A: The Intel Core i5-8400 wins 9 of the 17 recorded head-to-head tests, while the Intel Core 3 N355 wins 8. The split is nearly even, but the i5-8400 edges ahead in total victories.

Q: What is the biggest single benchmark victory for the Intel Core 3 N355?

A: The N355's most decisive win comes in PassMark data encryption, where it scores 8121 versus the i5-8400's 2824, a 187.6% advantage. That is the largest delta in either direction across the entire head-to-head set.

Q: Where does the Intel Core i5-8400 post its largest win?

A: In PassMark extended instructions, the i5-8400 scores 11543 against 5968 for the N355, a 48.3% lead. It also wins Cinebench R23 multicore by a 32.9% margin, scoring 7847 versus 5262.

Q: Are there any tests where the two CPUs are nearly tied?

A: Yes. PassMark physics shows a 1.6% difference, with the i5-8400 at 635 and the N355 at 625. PassMark floating point math is also close, with the N355 ahead by 3.1% (22695 versus 22006).

Q: What are the power and platform differences between the two?

A: The Intel Core 3 N355 is a 15 W mobile chip on Intel BGA 1264, while the Intel Core i5-8400 is a 65 W desktop chip on Intel Socket 1151. The N355 is still in active production, whereas the i5-8400 is marked end-of-life.

The Verdict

The data points to two very different design philosophies. The Intel Core 3 N355 is a modern, power-sipping mobile part with 8 cores and 8 threads, built for efficiency and portability. The Intel Core i5-8400 is an older desktop workhorse with 6 cores and 6 threads, designed for sustained throughput in a powered chassis.

Who should pick which? Systems builders looking for a compact, low-power platform with strong integer math and encryption performance should favor the Core 3 N355. It wins 8 head-to-head tests, including Cinebench R15 and R20 multicore, and its 15 W TDP makes it suitable for fanless or small-form-factor designs. The N355 also holds a higher average benchmark score (13492 versus 12765), so on aggregate it is the faster chip in the database's records.

Desktop users who already own an LGA 1151 board or need the i5-8400's specific strengths should stick with the older part. It wins long-form Cinebench R23 multicore by a 32.9% margin, dominates extended instruction workloads by 48.3%, and leads in single-thread PassMark testing by 9.2%. Its 65 W TDP and dual-channel memory support also suggest better sustained memory bandwidth in desktop workloads.

The verdict is not a clean sweep either way. The i5-8400 wins more individual tests, but the N355 wins the aggregate score. The deciding factor is workload: encryption, integer math, and short render bursts favor the N355; extended rendering, compression, and legacy desktop tasks favor the i5-8400.

Head-to-Head Benchmarks

The head-to-head results reveal a fascinating split between short and long workloads. In Cinebench R15 multicore, the Core 3 N355 scores 822 against 790 for the i5-8400, a 4.1% margin. The gap widens in Cinebench R20 multicore, where the N355 leads 3612 to 3295, a 9.6% advantage. Single-core results follow a similar pattern: the N355 wins R15 single-core by 51.4% (168 versus 111) and R20 single-core by 9.7% (509 versus 464).

Then the pattern flips in Cinebench R23. The i5-8400 takes multicore with 7847 against 5262, a 32.9% lead, and single-core with 1107 versus 1039, a 6.1% edge. This reversal suggests the i5-8400 scales better under extended sustained load, likely due to its higher 65 W power envelope and dual-channel memory.

PassMark tests show an even more dramatic divergence. The N355 dominates data encryption by 187.6% (8121 versus 2824) and integer math by 32.5% (33894 versus 25573). It also wins multithread by 10.3% (10174 versus 9225) and floating point math by 3.1% (22695 versus 22006).

The i5-8400 counters with a 48.3% lead in extended instructions (11543 versus 5968), a 27% lead in prime number finding (37 versus 27), and a 9.6% win in data compression (129951 versus 117435). It also takes random string sorting by 7.8% (15952 versus 14706) and single-thread PassMark by 9.2% (2371 versus 2153). Physics is nearly even, the i5-8400 ahead by just 1.6% (635 versus 625).

Specification Differences

The two CPUs diverge sharply on paper. The Core 3 N355 uses 8 cores and 8 threads, while the i5-8400 uses 6 cores and 6 threads. Base clocks differ: the N355 runs at 1.90 GHz, the i5-8400 at 2.80 GHz. Boost clocks are closer, with the N355 at 3.90 GHz and the i5-8400 at 4.00 GHz.

Thermal design power is a major separator: the N355 draws 15 W, the i5-8400 draws 65 W. The N355 uses Intel BGA 1264, the i5-8400 uses Intel Socket 1151. The N355 is classified as Mobile, the i5-8400 as Desktop. Production status also differs: the N355 is Active, the i5-8400 is End-of-life.

Memory support is another differentiator. The N355 supports DDR4, DDR5, and LPDDR5 over a single-channel bus with 38.4 GB/s bandwidth. The i5-8400 supports only DDR4 over a dual-channel bus with 42.7 GB/s bandwidth. PCIe lane counts differ as well: 9 Gen 3 lanes for the N355, 16 Gen 3 lanes for the i5-8400.

Integrated graphics differ: the N355 carries UHD Graphics 770, the i5-8400 carries UHD Graphics 630. Die size is known only for the i5-8400 at 154 mm². Launch MSRP for the i5-8400 was $182; no launch MSRP is recorded for the N355.

Architecture Differences

The Core 3 N355 is built on Intel's Twin Lake architecture, listed as part of the Core 3 (Alder Lake-N) generation, fabricated on a 10 nm process. The i5-8400 uses Coffee Lake, fabricated on a 14 nm process. Both are Intel foundry parts, but the process gap is significant: 10 nm versus 14 nm explains part of the N355's efficiency advantage.

Cache layouts reflect the generational shift. The N355 has 96 KB of L1 per core, 2 MB of shared L2, and 6 MB of shared L3. The i5-8400 has 64 KB of L1 per core, 256 KB of L2 per core, and 9 MB of shared L3. The i5-8400's larger L3 cache (9 MB versus 6 MB) likely contributes to its wins in compression and extended instruction workloads.

The N355's memory controller is single-channel, a notable constraint for a chip with 8 cores. The i5-8400's dual-channel controller provides 42.7 GB/s of bandwidth, 11.2% higher than the N355's 38.4 GB/s. This bandwidth advantage may explain why the i5-8400 wins sustained rendering tests like Cinebench R23 multicore.

Neither chip supports ECC memory, and both have locked multipliers. The N355 supports a wider range of memory types, including DDR5 and LPDDR5, which the i5-8400 cannot use. The i5-8400's 16 PCIe Gen 3 lanes double the N355's 9 lanes, a meaningful difference for desktop expansion.

Where Each One Wins

Intel Core 3 N355 wins in: data encryption by 187.6%, integer math by 32.5%, PassMark multithread by 10.3%, Cinebench R20 multicore by 9.6%, Cinebench R20 single-core by 9.7%, Cinebench R15 multicore by 4.1%, floating point math by 3.1%, and Cinebench R15 single-core by 51.4%. It also holds the higher aggregate average benchmark score at 13492 versus 12765.

Intel Core i5-8400 wins in: Cinebench R23 multicore by 32.9%, extended instructions by 48.3%, prime number finding by 27%, data compression by 9.6%, single-thread PassMark by 9.2%, random string sorting by 7.8%, Cinebench R23 single-core by 6.1%, and physics by 1.6%. It also wins the overall head-to-head count, 9 tests to 8.

The pattern is clear. The N355 excels at short-burst compute, encryption, and integer-heavy workloads. The i5-8400 dominates sustained rendering, legacy instruction sets, and compression tasks. The N355 is the better choice for mobile or low-power systems where encryption and integer math matter. The i5-8400 remains competitive for desktop users running long render jobs or older software that relies on extended instructions. The recorded data supports both picks, depending entirely on the workload.