Intel Core i5-7600K vs Intel Core i5-8400H Comparison

A 45-watt mobile chip beating a 91-watt desktop part in six of eight recorded tests is the kind of result that invites a closer look. The database places the Intel Core i5-8400H, a Coffee Lake-H processor soldered to BGA 1444-socket-class mobile platforms, against the Intel Core i5-7600K, a Kaby Lake desktop CPU on Socket 1151. On paper the desktop part should dominate: higher clocks, an unlocked multiplier, double the rated power envelope. The recorded data tells a more complicated story, with the mobile chip sweeping every Cinebench test and the desktop chip answering decisively in Geekbench.

The Verdict

The data splits cleanly along workload lines. If sustained multi-core rendering throughput is the priority, the i5-8400H is the pick: it wins Cinebench R15, R20, and R23 in both multi-core and single-core modes, a clean six-test sweep with margins between 9.8 and 10.5 percent. If the workload looks more like the mixed, bursty, lightly threaded profile Geekbench captures, the i5-7600K wins both Geekbench tests, by 13.8 percent multi-core and 15.8 percent single-core, which is a wider gap than any of the i5-8400H's Cinebench wins.

Platform considerations sharpen the choice. The i5-8400H is an end-of-life, soldered mobile part with a locked multiplier, so it exists only inside whatever laptop it shipped in. The i5-7600K remains listed as active, sits on Socket 1151, and has an unlocked multiplier, making it the only one of the two that supports user overclocking. Overall standing in the database is nearly identical: the i5-8400H sits at the 45th percentile versus the i5-7600K's 44th, with average benchmark scores of 2003 versus 1976. Neither is a class leader today; both hover in the same crowded middle tier.

Head-to-Head Benchmarks

The Cinebench results are remarkably consistent. In R15 multi-core, the i5-8400H scores 644 against 583, a 10.5 percent win. R15 single-core goes 90 to 82, 9.8 percent. R20 multi-core: 2684 to 2432, 10.4 percent. R20 single-core: 378 to 343, 10.2 percent. R23 multi-core: 6392 to 5792, 10.4 percent. R23 single-core: 902 to 817, again 10.4 percent. Six tests, six wins, and a margin that barely moves. That uniformity is itself informative: it suggests the gap is architectural rather than situational, since a scheduling or thermal fluke would not repeat across three Cinebench generations and both thread counts.

Then Geekbench flips the picture entirely. The i5-7600K posts 4239 multi-core to the i5-8400H's 3656, and 1522 single-core to 1281. Those are 13.8 and 15.8 percent wins for the desktop chip, larger than any Cinebench margin in either direction. How can one processor win every Cinebench test by ten percent and then lose both Geekbench tests by fourteen to sixteen? The spec sheet offers a plausible thread: the i5-7600K runs a 3.80 GHz base and 4.20 GHz boost, against the i5-8400H's 2.50 base and 4.10 boost. Geekbench's short bursts favor high sustained clocks, while Cinebench's longer rendering runs reward the i5-8400H's eight threads, hyper-threading the 7600K lacks, and its doubled L3 cache of 12 MB versus 6 MB. The database cannot prove causation, but the pattern fits.

Context from each chip's rival cluster confirms how evenly matched they are. The i5-8400H's average score of 2003 sits within a tenth of a percent of the AMD Ryzen 7 2800H (2002), the Intel Xeon D-1712TR (2004), and the Intel Core i5-8400T (2001). The i5-7600K's 1976 is similarly bracketed by the Intel Core i3-N305 (1979), the Xeon E3-1245 v5 (1973), the Core i7-10810U (1971), and the AMD Ryzen 3 2300X (1968). These are processors occupying the same performance band despite coming from different market segments.

FAQ

Q: Which processor wins more benchmark tests overall?

A: The i5-8400H wins six of the eight recorded head-to-head tests, all six Cinebench runs. The i5-7600K takes the two Geekbench tests.

Q: Can either processor be overclocked?

A: Only the i5-7600K. It has an unlocked multiplier. The i5-8400H is locked and is soldered to its mobile platform via BGA 1444, so it offers no tuning headroom.

Q: Are both chips still in production?

A: No. The i5-8400H is listed as end-of-life. The i5-7600K is listed as active.

Q: How do their positions in the database compare?

A: Nearly identically. The i5-8400H ranks in the 45th percentile of all recorded CPUs with an average score of 2003; the i5-7600K sits at the 44th percentile with 1976. The two are separated by rivals as close as the Ryzen 7 2800H on one side and the Ryzen 3 2300X on the other.

Q: Do they support the same memory?

A: Both support DDR4 and neither supports ECC. The 7600K's record additionally lists dual-channel operation with 38.4 GB/s of bandwidth; no bus or bandwidth figures are recorded for the 8400H.

Q: Which chip has the faster clocks?

A: The i5-7600K, on paper: 3.80 GHz base and 4.20 GHz boost against 2.50 and 4.10 for the i5-8400H. Yet the 8400H posts the higher single-core Cinebench scores, so rated clocks clearly do not tell the whole story.

Specification Differences

The two diverge in nearly every practical dimension. The i5-8400H is a mobile part with a 45-watt TDP on the BGA 1444 socket; the i5-7600K is a desktop part with a 91-watt TDP on Socket 1151. The mobile chip pairs 4 cores with 8 threads, while the desktop chip runs the same 4 cores with only 4 threads. Base and boost clocks favor the 7600K, 3.80 and 4.20 GHz against 2.50 and 4.10. The cache picture favors the 8400H strongly at L3: 12 MB shared versus 6 MB, while L1 and L2 are identical at 64 KB and 256 KB per core.

Other differences follow the market segment. The 7600K's record includes a dual-channel memory bus, 38.4 GB/s of memory bandwidth, and PCIe Gen 3 with 16 CPU lanes; the 8400H's record lists none of these. The 8400H's die size is recorded at 126 mm², with no die size listed for the 7600K. The 8400H carries the UHD 630 integrated GPU, the 7600K the HD 630. Production status, release dates, part numbers, and multiplier lock state all differ as noted above. Both support DDR4 without ECC, and both were fabbed by Intel on 14 nm.

Architecture Differences

Despite sharing Intel's 14 nm process, the two represent consecutive architecture generations. The i5-7600K is Kaby Lake, released in January 2017; the i5-8400H is Coffee Lake-H, released in April 2018. The key architectural difference visible in the data is threading: Coffee Lake-H brings hyper-threading to this 4-core part for 8 threads, while Kaby Lake's i5-7600K runs one thread per core. That, combined with the doubled 12 MB L3 cache, is the most likely structural explanation for the i5-8400H's uniform Cinebench advantage, particularly in multi-core runs where eight hardware threads face four.

The 7600K's counter-advantages are frequency and thermal room. A 91-watt desktop envelope lets it hold much higher clocks than a 45-watt mobile design, and that shows up exactly where short-burst tests measure it: Geekbench, where it wins by its largest margins of the entire comparison. The integrated graphics differ in branding (HD 630 versus UHD 630), but the recorded data includes no graphics benchmark scores, so no performance claim can be made there. Neither chip supports ECC memory.

Where Each One Wins

The i5-8400H's territory is sustained threaded throughput: rendering, encoding, and any workload that scales past four threads. Its 10.4 percent R23 multi-core win (6392 versus 5792) and identical R20 margin describe a chip that keeps eight threads fed for long runs, aided by 12 MB of shared L3. It also, curiously, wins every single-core Cinebench test despite lower rated clocks, which suggests strong per-clock efficiency from the newer generation under sustained load.

The i5-7600K's territory is responsiveness in lightly threaded and mixed workloads, where its 15.8 percent Geekbench single-core lead (1522 versus 1281) is the single largest margin in the entire dataset. It is also the only option of the two for builders and tinkerers: Socket 1151, an unlocked multiplier, PCIe Gen 3 with 16 CPU lanes, and an active production status give it a flexibility the soldered, end-of-life 8400H cannot match. The desktop chip trades nearly half the power budget and all of the thread count for clocks, and the data shows the exchange is worth making only for workloads that never need more than four threads at a time. For everything heavier, the mobile upstart wins.