Intel Core i5-8400H vs Intel Core i7-5775R Comparison

Head-to-Head Benchmarks

The head-to-head data shows a remarkably close contest between these two processors, with the Intel Core i5-8400H taking the majority of benchmark wins. Out of eight recorded comparisons, the i5-8400H wins six, while the i7-5775R wins two. The margins, however, are often paper-thin, making this a nuanced comparison rather than a clear knockout.

Starting with multi-core Cinebench results, the i5-8400H edges ahead in every version of the test. In Cinebench R15 multicore, the i5-8400H scores 644 against the i7-5775R's 641, a delta of -0.5%. The pattern repeats in Cinebench R20 multicore, where the i5-8400H posts 2684 versus 2671, again a 0.5% lead. In Cinebench R23 multicore, the i5-8400H scores 6392 compared to 6360, maintaining that same 0.5% advantage. These are marginal differences, within the noise of typical run-to-run variation, but the consistency across all three Cinebench versions is notable.

Single-core Cinebench results are even closer. In Cinebench R15 singlecore, both processors score exactly 90, a dead heat. In Cinebench R20 singlecore, the i5-8400H leads 378 to 376, a 0.5% edge. In Cinebench R23 singlecore, the i5-8400H scores 902 against 897, a 0.6% advantage. Again, these deltas are practically negligible, but the direction is consistent.

The Geekbench results tell a different story, and this is where the i7-5775R gets its two wins. In Geekbench multicore, the i7-5775R scores 3996 against the i5-8400H's 3656, a substantial 9.3% lead. This is the largest delta in the entire comparison. In Geekbench singlecore, however, the i5-8400H reverses the trend with a score of 1281 versus 1218, a 4.9% advantage for the newer chip.

The overall average benchmark scores reflect this split. The i7-5775R has an average score of 2031, while the i5-8400H sits at 2003. Both processors rank at the 45th percentile among all CPUs in the database, placing them squarely in the same performance tier. The i7-5775R's nearest rivals include the Intel Xeon E3-1240 v5 at 2030, the Xeon E3-1280 v5 at 2029, and the Xeon E3-1260L v5 at 2029, all within 0.1% of its average. The i5-8400H's nearest rivals include the AMD Ryzen 7 2800H at 2002, the Intel Xeon D-1712TR at 2004, and the Intel Core i5-8400T at 2001, again all within 0.1%.

Architecture Differences

The architectural gap between these two chips spans three years of Intel design evolution. The i7-5775R is built on the Broadwell architecture, released in May 2015, while the i5-8400H uses Coffee Lake-H, released in April 2018. Both are fabricated on Intel's 14 nm process node, but the die sizes tell an interesting story. The i7-5775R has a die size of 182 mm², while the i5-8400H is significantly smaller at 126 mm².

Both processors feature 4 cores and 8 threads, so thread-level parallelism is identical. The clock speeds, however, differ in important ways. The i7-5775R has a base clock of 3.30 GHz and a boost clock of 3.80 GHz. The i5-8400H starts lower at 2.50 GHz base but boosts much higher to 4.10 GHz. This higher boost clock explains the i5-8400H's single-core advantages in Cinebench and Geekbench, as it can reach higher frequencies under light load.

Cache configuration is another key divergence. Both share 64 KB of L1 and 256 KB of L2 per core, but the L3 cache is doubled on the i5-8400H: 12 MB shared versus 6 MB shared on the i7-5775R. This larger L3 cache likely contributes to the i7-5775R's strong Geekbench multicore showing, or at least helps the i5-8400H stay competitive despite its lower base clock.

Memory support differs by generation. The i7-5775R uses DDR3 memory with dual-channel support and a memory bandwidth of 29.9 GB/s. The i5-8400H uses DDR4 memory, though its memory bus configuration and bandwidth are not recorded in the database. The shift from DDR3 to DDR4 is a notable architectural change, impacting both bandwidth and latency characteristics.

The integrated graphics also differ. The i7-5775R features Iris Pro Graphics 6200, while the i5-8400H has UHD 630. Both processors lack ECC memory support. The i7-5775R uses the Intel BGA 1364 socket, while the i5-8400H uses Intel BGA 1440, and neither has an unlocked multiplier.

Thermal design power shows a meaningful difference: the i7-5775R is rated at 65 watts, while the i5-8400H draws 45 watts. This means the i5-8400H achieves its benchmark results with a lower TDP, which is significant for its mobile market segment.

The Verdict

The data indicates a narrowly split decision depending on workload priorities. The i5-8400H wins the majority of benchmark comparisons, six out of eight, and holds advantages in both single-core and multi-core Cinebench tests, as well as Geekbench single-core. Its higher boost clock of 4.10 GHz and larger 12 MB L3 cache appear to give it the edge in most synthetic rendering workloads.

However, the i7-5775R is not without merit. Its 9.3% victory in Geekbench multicore is the largest margin in the entire comparison, and its 65-watt TDP, while higher, might offer better sustained performance in some scenarios. The i7-5775R also carries a launch MSRP of $384, while the i5-8400H has no recorded launch price.

For users prioritizing raw threaded performance in Geekbench-style workloads, the i7-5775R deserves consideration. For anyone else, the i5-8400H's consistent Cinebench wins and higher boost clock make it the more balanced choice. Both processors sit at the 45th percentile overall, so neither is a top-tier performer in the current market. The i5-8400H is the safer pick for general productivity, while the i7-5775R is the specialist for certain memory-sensitive tasks.

FAQ

Q: Which processor has a higher boost clock?

A: The Intel Core i5-8400H has a boost clock of 4.10 GHz, while the Intel Core i7-5775R boosts to 3.80 GHz.

Q: How do the Cinebench R23 scores compare?

A: In Cinebench R23 multicore, the i5-8400H scores 6392 against the i7-5775R's 6360, a 0.5% lead. In single-core, the i5-8400H scores 902 against 897, a 0.6% advantage.

Q: Which processor has the larger L3 cache?

A: The Intel Core i5-8400H has 12 MB of shared L3 cache, twice the 6 MB found on the Intel Core i7-5775R.

Q: What is the memory type for each processor?

A: The i7-5775R supports DDR3 memory, while the i5-8400H supports DDR4 memory. The i7-5775R has a dual-channel memory bus with 29.9 GB/s bandwidth, while the i5-8400H's memory bus details are not recorded.

Q: Which processor has a higher TDP?

A: The Intel Core i7-5775R has a TDP of 65 watts, while the Intel Core i5-8400H has a TDP of 45 watts.

Q: In which benchmark does the i7-5775R beat the i5-8400H by the largest margin?

A: The i7-5775R leads by 9.3% in Geekbench multicore, scoring 3996 against the i5-8400H's 3656.

Where Each One Wins

The Intel Core i5-8400H wins in the majority of recorded benchmarks, but the victories are concentrated in Cinebench and single-core tests. It takes the lead in Cinebench R15 multicore (644 versus 641), R20 multicore (2684 versus 2671), R23 multicore (6392 versus 6360), R20 single-core (378 versus 376), and R23 single-core (902 versus 897). It also wins Geekbench single-core with 1281 versus 1218, a 4.9% margin. Its higher boost clock and larger cache appear to benefit these rendering and single-threaded workloads.

The Intel Core i7-5775R wins only two benchmarks, but one is a decisive victory. Its Geekbench multicore score of 3996 versus 3656 represents a 9.3% lead, the largest single delta in this comparison. It also ties in Cinebench R15 single-core at 90 points each, though the database credits the win to the i7-5775R. This suggests that in certain multi-threaded, memory-intensive scenarios, the i7-5775R's architecture retains a real advantage despite being older.

For users running Cinebench-based rendering or single-threaded applications, the data points to the i5-8400H. For users running Geekbench-class workloads that stress memory bandwidth, the i7-5775R may be the better fit.

Specification Differences

The two processors differ on several key specifications. The i7-5775R has a base clock of 3.30 GHz, while the i5-8400H runs at 2.50 GHz. The boost clock favors the i5-8400H at 4.10 GHz versus 3.80 GHz. TDP is 65 watts for the i7-5775R and 45 watts for the i5-8400H.

The socket is different: Intel BGA 1364 for the i7-5775R versus Intel BGA 1440 for the i5-8400H. The architecture is Broadwell for the i7-5775R and Coffee Lake for the i5-8400H. Process node is 14 nm for both. Die size is 182 mm² for the i7-5775R and 126 mm² for the i5-8400H.

Cache sizes: both have 64 KB L1 and 256 KB L2 per core, but L3 differs at 6 MB shared for the i7-5775R and 12 MB shared for the i5-8400H. Memory support is DDR3 for the i7-5775R with a dual-channel bus and 29.9 GB/s bandwidth; the i5-8400H uses DDR4 with no recorded bus or bandwidth. Integrated graphics are Iris Pro Graphics 6200 versus UHD 630. The i7-5775R has a recorded launch MSRP of $384; the i5-8400H has none.