Intel Core i5-9400 vs Intel Core i7-5775C Comparison

The Intel Core i5-9400 and the Intel Core i7-5775C occupy similar performance tiers, but they achieve their positions through very different designs. Both processors land in the 47th percentile of all CPUs, and their average benchmark scores are close, with the i5-9400 at 2254 and the i7-5775C at 2224. The data reveals a consistent pattern: the newer i5-9400 wins nearly every multi-threaded and single-threaded test by a slim margin, while the older i7-5775C claims a single, notable victory in one Geekbench single-core test. This head-to-head is less about overwhelming dominance and more about incremental advantages across a wide range of workloads.

Head-to-Head Benchmarks

The benchmark results show a clear, though narrow, trend favoring the Intel Core i5-9400. Across the Cinebench suite, the i5-9400 wins all six tests, with deltas that hover around 1% to 1.2%. In Cinebench R15, the i5-9400 scores 668 versus 660 in multi-core, a 1.2% lead, and 94 versus 93 in single-core, a 1.1% lead. The pattern holds in Cinebench R20, where the i5-9400 posts 2784 against 2750 in multi-core (1.2%) and 392 against 388 in single-core (1%). Cinebench R23 continues the trend, with the i5-9400 leading 6629 to 6549 in multi-core and 935 to 924 in single-core, both representing 1.2% advantages.

The Geekbench results offer a more mixed picture. In Geekbench multi-core, the i5-9400 wins decisively, scoring 5141 against the i7-5775C's 4989, a 3% delta that represents the largest margin in either direction across all tests. However, in Geekbench single-core, the i7-5775C strikes back, winning with a score of 1441 against the i5-9400's 1389. This 3.6% delta in favor of the i7-5775C is the only benchmark where it emerges victorious, and it is also the largest single performance gap recorded between the two CPUs. This single-core Geekbench win for the older chip is notable, suggesting that in certain lightly-threaded scenarios, the i7-5775C's higher base clock of 3.30 GHz can offset its architectural age.

Overall, the win count is decisively in favor of the i5-9400, which takes 7 of the 8 head-to-head benchmarks. The i7-5775C's sole win, while significant in its margin, does not compensate for the multi-core deficit. The data indicates that the i5-9400 is consistently ahead in Cinebench, a suite known for rendering and multi-threaded performance, while the i7-5775C shows a specific strength in Geekbench's single-core test. For most users, the i5-9400's broad consistency makes it the stronger performer, but the i7-5775C's single-test victory prevents a total sweep.

Architecture Differences

The two processors come from different eras and platforms. The Intel Core i5-9400 is built on the Coffee Lake architecture, using a 14 nm process node, and is part of the Core i5 (Coffee Lake Refresh) generation. It features 6 cores and 6 threads, with a base clock of 2.90 GHz and a boost clock of 4.10 GHz. Its cache hierarchy includes 64 KB of L1 and 256 KB of L2 per core, plus a shared 9 MB L3 cache. The i5-9400 supports DDR4 memory in a dual-channel configuration, with a memory bandwidth of 42.7 GB/s, and uses the Intel Socket 1151.

In contrast, the Intel Core i7-5775C is a Broadwell architecture part, also on a 14 nm process, from the Core i7 (Broadwell) generation. It has fewer physical cores, at 4, but employs Hyper-Threading to reach 8 threads. Its clocks are different, with a base of 3.30 GHz and a boost of 3.70 GHz. The L1 and L2 caches are identical to the i5-9400, but the shared L3 cache is smaller at 6 MB. The i7-5775C is built for the older Intel Socket 1150 and supports DDR3 memory, also dual-channel, with a lower memory bandwidth of 25.6 GB/s. It also has a larger die size at 182 mm².

The integrated graphics differ significantly. The i5-9400 comes with UHD 630, while the i7-5775C features Iris Pro Graphics 6200. Both support PCIe Gen 3 with 16 lanes, and neither supports ECC memory. The i7-5775C has an unlocked multiplier, whereas the i5-9400 does not. The i7-5775C is listed as having an "Active" production status, while the i5-9400 is "End-of-life." Finally, the i7-5775C was released on 2015-05-14, while the i5-9400 came later on 2018-10-18.

FAQ

Q: Which processor has more cores?

A: The Intel Core i5-9400 has 6 cores, while the Intel Core i7-5775C has 4 cores. However, the i7-5775C supports 8 threads due to Hyper-Threading, while the i5-9400 has 6 threads.

Q: What is the biggest performance difference between the two?

A: The largest delta is in the Geekbench single-core test, where the Intel Core i7-5775C wins by 3.6% with a score of 1441 against 1389. In multi-core, the i5-9400 wins by 3% in Geekbench, scoring 5141 versus 4989.

Q: Do they use the same memory type?

A: No. The Intel Core i5-9400 supports DDR4 memory with a bandwidth of 42.7 GB/s, while the Intel Core i7-5775C supports DDR3 memory with a bandwidth of 25.6 GB/s.

Q: Are both processors unlocked for overclocking?

A: No. The Intel Core i7-5775C has an unlocked multiplier, while the Intel Core i5-9400 does not.

Q: What is the release date difference?

A: The Intel Core i7-5775C was released on 2015-05-14, and the Intel Core i5-9400 was released on 2018-10-18.

Q: Which processor has a larger L3 cache?

A: The Intel Core i5-9400 has a larger shared L3 cache at 9 MB, compared to the 6 MB shared L3 cache on the Intel Core i7-5775C.

Specification Differences

The core specifications reveal clear generational shifts. The Intel Core i5-9400 has 6 cores and 6 threads, whereas the Intel Core i7-5775C has 4 cores and 8 threads. The base clock is higher on the i7-5775C at 3.30 GHz versus 2.90 GHz, but the boost clock is higher on the i5-9400 at 4.10 GHz versus 3.70 GHz. The L3 cache is larger on the i5-9400 (9 MB) than on the i7-5775C (6 MB). The sockets differ, with the i5-9400 using Intel Socket 1151 and the i7-5775C using Intel Socket 1150.

Memory support is another key divider. The i5-9400 uses DDR4 with 42.7 GB/s bandwidth, while the i7-5775C uses DDR3 with 25.6 GB/s. The integrated graphics are different, with the i5-9400 featuring UHD 630 and the i7-5775C featuring Iris Pro Graphics 6200. The production status differs, with the i5-9400 marked as "End-of-life" and the i7-5775C as "Active." The multiplier unlock status is also different, with the i7-5775C being unlocked and the i5-9400 locked. The release dates are distinct, as are the part numbers (SR3X5 for the i5-9400, SR2AG for the i7-5775C). The die size is only listed for the i7-5775C at 182 mm². The launch MSRP for the i7-5775C is $366.

The Verdict

Based strictly on the benchmark data, the Intel Core i5-9400 is the superior processor for the majority of tasks. It wins 7 out of 8 head-to-head tests, including all Cinebench R15, R20, and R23 benchmarks, and the Geekbench multi-core test. Its multi-core advantage is consistent, with deltas of 1.2% across the Cinebench suite and 3% in Geekbench. The i5-9400 also offers a larger L3 cache, newer memory support, and a higher boost clock, all of which contribute to its performance edge. The i7-5775C's only win is in Geekbench single-core, where it leads by 3.6%. This makes it a niche option for workloads that rely heavily on single-threaded performance as measured by that specific test.

However, the i7-5775C is not without merit. Its higher base clock and unlocked multiplier could appeal to users who prefer to manually overclock, and its "Active" production status suggests it is still a current product. The i5-9400, being "End-of-life," is an older product in its lifecycle. For a user building a new system, the i5-9400's broader performance profile and memory support make it the logical choice. The i7-5775C's single benchmark victory does not outweigh the i5-9400's consistent wins elsewhere. The data points to the i5-9400 as the default pick for anyone who values multi-core performance, which is critical for modern rendering and productivity workloads.

Where Each One Wins

The Intel Core i5-9400 wins in all Cinebench tests, which are indicative of rendering and 3D modeling workloads. Its 6 cores provide a tangible benefit in these multi-threaded tasks, yielding scores of 668, 2784, and 6629 in R15, R20, and R23 multi-core, respectively. It also wins in Geekbench multi-core with a score of 5141, suggesting an advantage in general multitasking and multi-threaded applications. The i5-9400's higher boost clock and larger L3 cache likely contribute to this broad superiority.

The Intel Core i7-5775C wins only in Geekbench single-core, with a score of 1441. This specific result indicates that in short, lightly-threaded bursts, the i7-5775C can outperform the i5-9400. Its higher base clock of 3.30 GHz gives it an edge in scenarios that do not allow for sustained boost activity. This makes it a potential choice for older software or specific single-threaded applications that are not well-optimized for multi-core processing. Outside of that niche, the data consistently favors the i5-9400. The i7-5775C's advantage is real but narrow, confined to a single benchmark metric.