Intel Core i5-11400 vs Intel Core Ultra 5 115U Comparison

The Intel Core Ultra 5 115U and the Intel Core i5-11400 represent two distinct philosophies from the same manufacturer, separated by nearly three years of design evolution. The Ultra 5 115U is a 15-watt mobile Meteor Lake part built for the 7 nm process, while the i5-11400 is a 65-watt desktop Rocket Lake chip on the older 14 nm node. The benchmark data reveals a stark narrative: the desktop part dominates almost every compute metric, yet the mobile part carves out specific victories in efficiency-oriented tests. With an average benchmark score of 16753 against 17067 for the i5-11400, the Ultra 5 115U trails by only 1.9% overall, despite losing 13 of 17 head-to-head comparisons. The story is not about raw speed but about where and how each processor chooses to spend its resources.

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Core i5-11400 holds the higher average benchmark score at 17067, compared to the Intel Core Ultra 5 115U's 16753. This places the i5-11400 in the 71st percentile of all CPUs, while the Ultra 5 115U sits just behind in the 70th percentile.

Q: How do the two chips compare in Cinebench R23 multi-core performance?

A: The Intel Core i5-11400 scores 14132 in Cinebench R23 multi-core, which is 23.2% higher than the Ultra 5 115U's 10855. This consistent 23.2% delta also appears in R15 and R20 multi-core tests, indicating a uniform performance gap in rendering workloads.

Q: Are there any benchmarks where the Ultra 5 115U wins?

A: Yes, the Ultra 5 115U wins four head-to-head tests: PassMark find prime numbers (53 vs 49, an 8.2% advantage), PassMark physics (898 vs 793, a 13.2% advantage), and PassMark single-thread (3057 vs 2990, a 2.2% advantage, appearing twice under slightly different names).

Q: What are the core and thread configurations of each processor?

A: The Intel Core Ultra 5 115U has 8 cores and 10 threads, while the Intel Core i5-11400 has 6 cores and 12 threads. The desktop chip has fewer physical cores but more threads, while the mobile chip has more cores but fewer threads.

Q: What memory types do the two processors support?

A: The Intel Core Ultra 5 115U supports DDR5 memory with a dual-channel bus and 89.6 GB/s bandwidth, while the Intel Core i5-11400 supports DDR4 with a dual-channel bus and 51.2 GB/s bandwidth. Neither supports ECC memory.

Q: What is the production status of each processor?

A: The Intel Core Ultra 5 115U is listed as "Active" production status, released on 2023-12-13. The Intel Core i5-11400 is marked "End-of-life" production status, released on 2021-03-15.

Where Each One Wins

The data paints a clear picture of specialization. The Intel Core i5-11400 wins every Cinebench test, every 3DMark test, and the vast majority of PassMark workloads, making it the obvious choice for sustained multi-threaded productivity. Its wins span compression (206952 vs 141945), encryption (10264 vs 8606), extended instructions (14901 vs 8620), integer math (57601 vs 41043), floating-point math (34004 vs 30538), multithread (16690 vs 13024), and random string sorting (23974 vs 15124). The deltas range from 10.2% in floating-point math to a massive 42.2% in extended instructions, showing that the Rocket Lake architecture simply executes more work per clock in most scenarios.

The Intel Core Ultra 5 115U's wins are narrower but revealing. It takes the PassMark physics test with a 13.2% margin (898 vs 793), suggesting better handling of physics simulation workloads. It also wins the prime number finding test by 8.2% (53 vs 49), which is a curious result given its overall lower integer math score. The single-thread victory is slim at 2.2% (3057 vs 2990), but it indicates that Meteor Lake's newer architecture can match or slightly exceed Rocket Lake in lightly-threaded bursts despite the massive TDP difference. The mobile chip wins where efficiency or specific instruction patterns matter, not where raw throughput dominates.

Architecture Differences

The architectural gap between these two processors is generational. The Intel Core Ultra 5 115U is built on Meteor Lake, a 7 nm process, while the Intel Core i5-11400 uses Rocket Lake on a 14 nm node. This process difference explains much of the efficiency disparity: the Ultra 5 115U operates at a 15-watt TDP, while the i5-11400 consumes 65 watts. The mobile chip has a base clock of 1500 MHz and a boost clock of 4.2 GHz, whereas the desktop chip runs at 2600 MHz base and 4.4 GHz boost. Despite the lower clocks, the Ultra 5 115U manages to nearly match the i5-11400 in single-thread performance, which speaks to the architectural improvements in Meteor Lake.

Cache layouts differ substantially. The Ultra 5 115U has 112 KB L1 per core, 2 MB L2 per core, and 10 MB shared L3. The i5-11400 has 80 KB L1 per core, 512 KB L2 per core, and 12 MB shared L3. The mobile chip's larger per-core L2 cache likely contributes to its physics and prime number wins, while the desktop chip's larger shared L3 helps in memory-heavy workloads. The i5-11400 has a die size of 276 mm², while the Ultra 5 115U's die size is not listed in the data. The integrated graphics also differ, with the Ultra 5 115U featuring Arc Xe-LPG 48EU and the i5-11400 using UHD Graphics 730.

Specification Differences

The two processors diverge across nearly every specification field. Core counts differ: 8 cores and 10 threads for the Ultra 5 115U versus 6 cores and 12 threads for the i5-11400. The socket types are incompatible: Intel BGA 2049 for the mobile chip versus Intel Socket 1200 for the desktop chip. The process nodes are generations apart, 7 nm versus 14 nm. The i5-11400 has a launch MSRP of $182, while the Ultra 5 115U has no listed launch MSRP.

Memory support differs fundamentally: the Ultra 5 115U uses DDR5 with 89.6 GB/s bandwidth, while the i5-11400 uses DDR4 with 51.2 GB/s bandwidth. PCIe lanes also differ, with the Ultra 5 115U offering Gen 4 with 12 lanes (CPU only) and the i5-11400 offering Gen 4 with 20 lanes (CPU only). The market segments are opposite: Mobile for the Ultra 5 115U and Desktop for the i5-11400. Production statuses are also opposite, with the Ultra 5 115U Active and the i5-11400 End-of-life. The part numbers are SRN6F for the Ultra 5 115U and SRKP0 for the i5-11400. Neither processor has an unlocked multiplier.

Head-to-Head Benchmarks

The head-to-head data shows a dominant performance from the Intel Core i5-11400 in most tests. The Cinebench suite is entirely one-sided: the i5-11400 wins R15 multicore (1424 vs 1094), R15 singlecore (200 vs 154), R20 multicore (5935 vs 4559), R20 singlecore (837 vs 643), R23 multicore (14132 vs 10855), and R23 singlecore (1995 vs 1532). Every single one of these shows exactly a 23.2% delta in favor of the desktop chip, which is remarkably consistent and suggests the Ultra 5 115U simply cannot sustain the same level of multi-threaded throughput.

PassMark results are more varied. The biggest win for the i5-11400 is in extended instructions, where it scores 14901 against the Ultra 5 115U's 8620, a 42.2% gap. Random string sorting shows a 36.9% delta (23974 vs 15124), and data compression shows a 31.4% delta (206952 vs 141945). Integer math favors the i5-11400 by 28.7% (57601 vs 41043), multithread by 22% (16690 vs 13024), and data encryption by 16.2% (10264 vs 8606). Floating-point math is closer at 10.2% (34004 vs 30538), but still a clear win for the desktop part.

The Ultra 5 115U's wins are notable for their specificity. PassMark physics shows a 13.2% advantage (898 vs 793), which is the largest margin for the mobile chip. Prime number finding gives it an 8.2% edge (53 vs 49). The single-thread tests are nearly identical, with the Ultra 5 115U winning by 2.2% (3057 vs 2990) in both PassMark single_thread and PassMark singlethread. These wins suggest that in certain instruction patterns, the newer architecture can overcome the clock speed disadvantage, but these are isolated cases rather than a trend.

The Verdict

The data indicates that the Intel Core i5-11400 is the superior processor for almost any compute-intensive task. Its 23.2% advantage across the entire Cinebench suite, along with wins in compression, encryption, extended instructions, integer math, floating-point math, multithread, and random string sorting, makes it the clear choice for rendering, data processing, and heavy productivity workloads. The 65-watt TDP and desktop socket are justified by the consistent performance gains, and its percentile ranking of 71 versus the Ultra 5 115U's 70 reflects this edge. Users who need maximum throughput from a desktop platform should select the i5-11400 without hesitation.

The Intel Core Ultra 5 115U is a different animal entirely. Its 15-watt TDP and mobile BGA socket make it suitable for laptops where power efficiency is paramount. The data shows it wins the PassMark physics test by 13.2% and matches the i5-11400 in single-thread performance with a 2.2% edge, which is impressive given the massive TDP difference. Its DDR5 memory support and larger per-core L2 cache suggest it is designed for efficiency-focused workloads rather than raw compute. The Ultra 5 115U is the right choice for mobile users who need decent performance in a power-constrained environment, particularly if physics simulation or light single-threaded tasks are the primary use case. The i5-11400 is the clear winner for desktop users, while the Ultra 5 115U serves a niche but valid mobile role.