Intel Core i5-12400F vs Intel Core i7-1355U Comparison

The Intel Core i5-12400F and Intel Core i7-1355U represent two fundamentally different approaches to x86 processing: a desktop-focused, high-power part versus a mobile-oriented, efficiency-first chip. The benchmark data reveals a clear performance hierarchy, but the story is more nuanced than a simple tally of wins. The i5-12400F secures 15 benchmark victories, while the i7-1355U manages only 2, yet the nature of those losses and wins tells a compelling tale about intended use cases and architectural priorities.

Head-to-Head Benchmarks

The most decisive victory for the Intel Core i5-12400F comes in the PassMark extended instructions test, where it scores 15834 against the i7-1355U's 8726. That is a staggering 81.5% advantage, indicating a massive lead in workloads that leverage advanced CPU instruction sets. This is not a marginal difference; it is a categorical one, suggesting the desktop chip's execution engine is far more robust for complex computational tasks.

Multi-core performance heavily favors the i5-12400F, as expected given its 65W TDP versus the i7-1355U's 15W. In Cinebench R23 multi-core, the i5-12400F scores 12380, which is 49.4% higher than the i7-1355U's 8286. The data compression test shows a similar gap, with the i5-12400F scoring 233327 compared to 155727, a 49.8% lead. Even in less extreme multi-threaded tasks like PassMark integer math, the i5-12400F wins by 15.4%, scoring 59995 versus 52002. The pattern is consistent: sustained multi-core workloads are the i5-12400F's domain.

The i7-1355U's two wins are both in single-core Cinebench tests, and they are narrow. In Cinebench R23 single-core, the i7-1355U scores 1825 against 1680, a 7.9% advantage. In Cinebench R15 single-core, it wins 255.5 to 244, a 4.5% edge. These are the only tests where the mobile chip pulls ahead, and they highlight its ability to reach higher boost clocks quickly. However, the i5-12400F fights back in other single-threaded measures: in PassMark single-thread, it wins 3481 to 3444, a slim 1.1% margin. This suggests the i7-1355U's single-core wins are specific to Cinebench's rendering engine, not a universal single-thread advantage.

The middle ground reveals the i5-12400F's consistent pressure. In PassMark physics, it scores 1202 versus 888, a 35.4% lead. In floating-point math, it wins 46759 to 34965, a 33.7% margin. Even in data encryption, a task that often scales with memory bandwidth and cache, the i5-12400F wins 11679 to 9831, an 18.8% advantage. The i7-1355U's higher core count (10 vs 6) and threads (12 vs 12) cannot compensate for the i5-12400F's superior power envelope and desktop-grade architecture.

The Verdict

The data is unambiguous for performance: the Intel Core i5-12400F is the superior processor. Its 49.4% lead in Cinebench R23 multi-core and 81.5% lead in extended instructions leave no room for doubt in compute-heavy scenarios. The i7-1355U's single-core wins in Cinebench are real but narrow, and they are offset by the i5-12400F's own single-thread victory in PassMark. Benchmark results indicate the i5-12400F is the choice for anyone prioritizing raw throughput, multi-threaded rendering, or instruction-heavy computation.

The i7-1355U, however, is not without merit. Its data shows a part designed for a different battlefield. With a 15W TDP and BGA 1744 socket, it is built for thin-and-light laptops where power draw and thermal output are the primary constraints. Its two single-core wins suggest it can feel responsive in bursty, lightly-threaded tasks. The i5-12400F, with its 65W TDP and LGA 1700 socket, requires a desktop platform and is not suited for portable systems. The verdict is not about which is "better" but which fits the system's physical and power requirements. For a desktop, the i5-12400F is the clear winner; for a mobile platform, the i7-1355U is the only viable option of the two.

Architecture Differences

The two CPUs are built on different Intel microarchitectures, though both use a 10 nm process node. The i5-12400F is based on Alder Lake-S, while the i7-1355U is based on Raptor Lake-U. This generational difference is significant, as Raptor Lake is a refinement of Alder Lake, but the implementation targets are distinct. The i5-12400F has 6 cores and 12 threads, while the i7-1355U has 10 cores and 12 threads. The i7-1355U's higher core count likely includes efficiency cores, which helps with multi-threading but does not overcome the i5-12400F's performance-per-core advantage in sustained workloads.

Cache configurations differ notably. The i5-12400F has 18 MB of shared L3 cache, while the i7-1355U has 12 MB. This 6 MB difference contributes to the i5-12400F's lead in data-heavy tasks. Both have 80 KB of L1 cache per core and 1.25 MB of L2 cache per core, so the core-level caches are identical. The base clocks are starkly different: the i5-12400F runs at 2.50 GHz, while the i7-1355U has a 1700.00 MHz base, but the i7-1355U boosts to 5.00 GHz versus the i5-12400F's 4.40 GHz. This higher boost clock explains the i7-1355U's single-core Cinebench wins.

Platform support separates them further. The i5-12400F uses Intel Socket 1700 and supports PCIe Gen 5 with 20 lanes, while the i7-1355U uses Intel BGA 1744 and supports PCIe Gen 4 with 8 lanes. The i5-12400F has no integrated graphics, requiring a discrete GPU, while the i7-1355U includes Iris Xe Graphics with 96 execution units. Both support DDR4 and DDR5 memory in dual-channel mode, and neither supports ECC memory. The i5-12400F has a die size of 163 mm², while the i7-1355U's die size is not listed.

FAQ

Q: Which CPU is faster in multi-core workloads?

A: The Intel Core i5-12400F wins all multi-core tests. It leads by 49.4% in Cinebench R23 multi-core (12380 vs 8286) and by 35.9% in PassMark multithread (19433 vs 14299).

Q: Does the i7-1355U ever win any benchmarks?

A: Yes, it wins two single-core Cinebench tests. It scores 1825 in Cinebench R23 single-core versus 1680 for the i5-12400F (a 7.9% lead) and 255.5 versus 244 in Cinebench R15 single-core (a 4.5% lead).

Q: How do their core counts and threads compare?

A: The i5-12400F has 6 cores and 12 threads, while the i7-1355U has 10 cores and 12 threads. Despite having more cores, the i7-1355U loses in multi-threaded performance.

Q: What is the TDP difference, and why does it matter?

A: The i5-12400F has a 65W TDP, while the i7-1355U has a 15W TDP. This means the i5-12400F can sustain higher power draw for longer periods, which is a key reason for its large multi-core leads.

Q: Do they support the same memory and PCIe specifications?

A: Both support DDR4 and DDR5 memory in dual-channel mode. However, the i5-12400F supports PCIe Gen 5 with 20 lanes, while the i7-1355U supports PCIe Gen 4 with 8 lanes.

Q: Does either CPU have integrated graphics?

A: The i5-12400F has no integrated graphics, requiring a discrete GPU. The i7-1355U includes Iris Xe Graphics with 96 execution units.

Where Each One Wins

The Intel Core i5-12400F wins in every multi-threaded and compute-intensive scenario. Its 49.8% lead in data compression and 41.2% lead in prime number finding make it ideal for content creation, video encoding, and scientific computing. The 33.7% advantage in floating-point math and 35.4% lead in physics simulations further cement its position for engineering and 3D rendering tasks. The 81.5% margin in extended instructions points to superiority in cryptography, simulation, and other specialized workloads. For desktop users who prioritize processing power above all, the i5-12400F is the definitive choice.

The Intel Core i7-1355U wins specifically in short-duration, single-threaded bursts, as shown by its Cinebench R23 and R15 single-core victories. This makes it suitable for responsive everyday computing—quick app launches, web browsing, and office productivity—where the workload is light and intermittent. Its integrated Iris Xe Graphics also means it can handle basic display output without a discrete GPU, which is a functional advantage for ultra-portable laptops. The 15W TDP allows for fanless or low-noise designs, making it a fit for passive-cooled or battery-optimized systems. Its wins are narrow but meaningful for mobile usability.

Specification Differences

The two processors differ on several key specification fields. The i5-12400F is a desktop part with a 65W TDP, while the i7-1355U is a mobile part with a 15W TDP. The i5-12400F uses Intel Socket 1700, whereas the i7-1355U uses Intel BGA 1744. The i5-12400F is based on Alder Lake architecture, while the i7-1355U is based on Raptor Lake. The i5-12400F has 6 cores and 12 threads; the i7-1355U has 10 cores and 12 threads. Base clocks are 2.50 GHz for the i5-12400F and 1700.00 MHz for the i7-1355U, while boost clocks are 4.40 GHz and 5.00 GHz, respectively.

The i5-12400F has 18 MB of shared L3 cache versus 12 MB for the i7-1355U. The i5-12400F supports PCIe Gen 5 with 20 lanes, while the i7-1355U supports PCIe Gen 4 with 8 lanes. The i5-12400F has no integrated graphics, while the i7-1355U features Iris Xe Graphics 96EU. The i5-12400F has a die size of 163 mm², while the i7-1355U's die size is not listed. The launch MSRP for the i5-12400F is $174, and for the i7-1355U it is $469. The i5-12400F released on 2022-01-03, while the i7-1355U released on 2023-01-03. Both are active production parts, have locked multipliers, and support DDR4 and DDR5 memory in dual-channel mode.