Intel Core i3-N305 vs Intel Core i5-8279U Comparison

The Intel Core i5-8279U and Intel Core i3-N305 are both mobile processors aimed at thin-and-light laptops, but they represent fundamentally different design philosophies from Intel. The i5-8279U is a 2019-era 14nm part built on the classic big-core Coffee Lake architecture, while the i3-N305 is a 2023-era 10nm chip using the efficient Gracemont cores from the Alder Lake-N family. Benchmark data shows a split decision: the i3-N305 dominates in most Cinebench and Geekbench tests, but the older i5-8279U takes a decisive win in Cinebench R23 multi-core and Geekbench single-core. Their average benchmark scores are nearly identical (1987 vs 1979), placing both at the 44th percentile of all CPUs, which means real-world differences will depend heavily on the specific workload.

FAQ

Q: Which processor has more cores?

A: The Intel Core i3-N305 has 8 cores, while the Intel Core i5-8279U has 4 cores. Both chips support 8 threads, meaning the i3-N305 does not use Hyper-Threading, whereas the i5-8279U does (4 cores / 8 threads).

Q: How do their average benchmark scores compare?

A: The i5-8279U has an average benchmark score of 1987, and the i3-N305 scores 1979. That is a negligible 0.4% difference, which is why both are in the 44th percentile of all CPUs. Their nearest rivals include the AMD Ryzen Embedded V1756B (scores 1986, 0.1% from the i5) and the Intel Core i5-7600K (scores 1976, 0.1% from the i3).

Q: Which chip has the higher boost clock?

A: The Intel Core i5-8279U boosts to 4.10 GHz. The Intel Core i3-N305 has a listed base clock of 100.00 GHz, which is clearly a data anomaly, but its boost clock is lower at 3.80 GHz.

Q: What are the major memory differences?

A: The i5-8279U supports only DDR4 memory in a dual-channel configuration with 34.1 GB/s bandwidth. The i3-N305 supports both DDR4 and DDR5, but only in a single-channel configuration, offering a higher theoretical bandwidth of 38.4 GB/s.

Q: Which chip is more power-efficient?

A: The i3-N305 has a TDP of 15W, which is significantly lower than the i5-8279U's 28W TDP. This makes the i3-N305 more suitable for fanless or ultra-portable designs.

Q: What is the launch MSRP difference?

A: The Intel Core i5-8279U had a launch MSRP of $320, while the Intel Core i3-N305 launched at $309.

Architecture Differences

The two chips are built on entirely different architectural foundations. The i5-8279U uses the Coffee Lake architecture on a 14 nm process node, with a die size of 126 mm² and 2,300 million transistors. It features 4 cores based on Intel's traditional big-core design, with 64 KB of L1 cache per core and 256 KB of L2 per core, sharing a 6 MB L3 cache. This is a mature design optimized for sustained single-thread performance and responsiveness.

In contrast, the i3-N305 uses the Gracemont architecture on a 10 nm process node, which is the efficiency-core design originally developed for Alder Lake. It has 8 physical cores, each with 96 KB of L1 cache, but L2 is organized as 2 MB per module. It shares the same 6 MB L3 cache as the i5. The Gracemont cores are designed for high throughput in multi-threaded workloads while consuming minimal power, which is reflected in its 15W TDP versus the i5's 28W.

The integrated graphics also differ substantially. The i5-8279U comes with Iris Pro Plus 655, a higher-tier GPU for its era. The i3-N305 uses UHD Graphics 770, which is a more modern but entry-level iGPU. Both chips use PCIe Gen 3, but the i5-8279U has 16 lanes (CPU only), while the i3-N305 has 9 lanes (CPU only). The i3-N305 also supports both DDR4 and DDR5 memory, whereas the i5-8279U is restricted to DDR4.

Head-to-Head Benchmarks

The benchmark results tell a story of two different strengths. In Cinebench R15 multi-core, the i3-N305 scores 829 against the i5-8279U's 634, a 23.5% advantage. The gap widens in Cinebench R15 single-core, where the i3-N305 scores 164.7 versus 89 for the i5, a massive 46% lead. This pattern continues in Cinebench R20: the i3-N305 wins multi-core with 3349 vs 2643 (21.1% ahead) and single-core with 472 vs 372 (21.2% ahead). The i3-N305 also wins Cinebench R23 single-core with 995 vs 888, a 10.8% margin.

However, the i5-8279U strikes back in Cinebench R23 multi-core. Here, the i5 scores 6294, while the i3-N305 manages only 5092. This gives the i5 a 23.6% victory, which is the largest single delta in the entire head-to-head set. In Geekbench, the results are split: the i3-N305 wins multi-core with 3881 vs 3764 (a narrow 3% margin), but the i5-8279U takes single-core with 1209 vs 1049, a solid 15.3% lead.

Overall, the i3-N305 wins 6 out of 8 benchmarks, but the i5-8279U wins the two most important ones for certain workloads: Cinebench R23 multi-core (often used for rendering tests) and Geekbench single-core (a proxy for general app responsiveness). The data suggests that the i3-N305's 8 cores give it an edge in lightly-threaded and moderately-threaded synthetic tests, but the i5's higher boost clock of 4.10 GHz and older big-core design give it a clear advantage in sustained heavy multi-threading and in specific single-threaded scenarios.

Specification Differences

The most obvious difference is core count: the i5-8279U has 4 cores and 8 threads, while the i3-N305 has 8 cores and 8 threads. Base clocks are listed as 2.40 GHz for the i5 and 100.00 GHz for the i3, though the latter appears to be a reporting error; the boost clocks are 4.10 GHz for the i5 and 3.80 GHz for the i3. TDP is a major differentiator, with the i5 at 28W and the i3 at 15W.

The process node and architecture are also distinct: 14 nm Coffee Lake vs 10 nm Gracemont. The i5 has a transistor count of 2,300 million and a die size of 126 mm², while the i3 does not have those figures listed. Cache configuration differs in L1 and L2: the i5 has 64 KB L1 per core and 256 KB L2 per core, while the i3 has 96 KB L1 per core and 2 MB L2 per module. Both share 6 MB of L3.

Memory support is a key split. The i5-8279U is limited to DDR4 with dual-channel memory and 34.1 GB/s bandwidth. The i3-N305 supports both DDR4 and DDR5 but only in single-channel mode, with a higher bandwidth of 38.4 GB/s. Neither supports ECC memory. The i5 uses socket Intel BGA 1526, while the i3 uses Intel BGA 1264. The i5 is end-of-life, released in April 2019, while the i3 is active, released in January 2023. Their part numbers are SREZ0 for the i5 and SRMDQ for the i3.

Where Each One Wins

The Intel Core i3-N305 is the clear winner in raw multi-threaded throughput for most tasks. It leads in Cinebench R15 multi-core (829 vs 634), Cinebench R20 multi-core (3349 vs 2643), and Geekbench multi-core (3881 vs 3764). It also wins in every single-core test except Geekbench single-core, where the i5-8279U takes the lead (1209 vs 1049). The i3-N305's 8 cores make it the better choice for parallel workloads like video encoding, compilation, or running many browser tabs, especially given its lower 15W TDP, which allows for thinner laptops with longer battery life. Its support for DDR5 memory (up to 38.4 GB/s) also gives it a theoretical memory bandwidth advantage.

The Intel Core i5-8279U wins where sustained heavy multi-threading and certain single-threaded tasks matter. Its Cinebench R23 multi-core score of 6294 is 23.6% higher than the i3-N305's 5092, which is a substantial margin in a modern rendering benchmark. This suggests that the i5's larger, more powerful cores can sustain high performance over longer periods, whereas the i3's efficiency cores may throttle or run out of steam in extended workloads. The i5 also wins Geekbench single-core with 1209 vs 1049, indicating better per-core performance for legacy applications that rely on a single thread. With a higher boost clock of 4.10 GHz and dual-channel memory support, the i5 is better suited for tasks like gaming on integrated graphics or running older software that expects traditional big-core behavior.

The Verdict

The benchmark data points to a clear split based on use case. For general mobile computing, the Intel Core i3-N305 is the more compelling choice. It wins 6 of 8 head-to-head benchmarks, including all Cinebench R15 and R20 tests, and offers double the cores of the i5-8279U. Its 15W TDP makes it far more suitable for fanless, ultra-portable designs, and its support for DDR5 memory gives it a modern memory pathway. If you are looking at a laptop for everyday productivity, web browsing, and light content creation, the i3-N305's performance is consistently ahead in most synthetic tests.

However, the Intel Core i5-8279U is not obsolete. Its decisive win in Cinebench R23 multi-core (6294 vs 5092, a 23.6% advantage) shows that it has a higher performance ceiling for sustained, heavy multi-threaded workloads like 3D rendering or complex simulations. Its Geekbench single-core win (1209 vs 1049, a 15.3% lead) also means it will feel snappier in older, less-threaded applications. The i5 also benefits from dual-channel memory, which can improve integrated graphics performance. If you prioritize maximum sustained performance over efficiency and are willing to accept a higher 28W TDP, the i5-8279U remains the stronger chip for specific demanding tasks. For everyone else, the i3-N305 offers better overall versatility and efficiency.