Intel Core i3-10305 vs Intel Core i7-8559U Comparison

The Intel Core i3-10305 and Intel Core i7-8559U are both 4-core, 8-thread processors, but the benchmark data shows a consistent and decisive performance gap in favor of the desktop part across every tested workload. The i3-10305 wins all six head-to-head comparisons, with a uniform 12.1% margin over the i7-8559U in both single-core and multi-core Cinebench tests. This makes the comparison less about raw capability—where the i3 is clearly superior—and more about platform context, integrated graphics, and the specific use case of a mobile versus desktop processor.

Head-to-Head Benchmarks

The most striking result is the consistency of the performance gap. In Cinebench R15 multi-core, the i3-10305 scores 788 against the i7-8559U’s 703, a 12.1% advantage. The single-core test tells the same story: 111 versus 99, again a 12.1% lead for the i3. This pattern holds exactly across all four other benchmarks—R20 multi-core (3287 vs 2933), R20 single-core (464 vs 414), R23 multi-core (7828 vs 6984), and R23 single-core (1105 vs 986)—with every deltaPct locked at 12.1%.

That uniformity is noteworthy. It suggests the performance difference is not workload-dependent but rather a fundamental throughput advantage. Despite sharing the same 14 nm process node, 4 cores, 8 threads, and 8 MB of L3 cache, the i3-10305’s higher base clock of 3.80 GHz versus 2.70 GHz gives it a structural edge. The boost clocks are identical at 4.50 GHz, but sustained performance—especially in multi-threaded tests—clearly favors the desktop chip with its 65 W TDP versus the mobile chip’s 28 W TDP.

The i7-8559U does have one benchmark result the i3 lacks: Geekbench scores of 4293 multi-core and 1384 single-core. However, there is no comparable Geekbench data for the i3-10305 in the fact pack, so these numbers cannot be used for a direct cross-processor comparison. Within the available shared benchmarks, the i3-10305 wins every round.

The average benchmark scores also reflect this hierarchy. The i3-10305 posts an average score of 2264, while the i7-8559U averages 2225. Both processors sit at the 47th percentile against all CPUs, indicating they are evenly matched in the broader market, but the i3 holds a 1.8% advantage in average score. The nearest rivals for each chip reinforce this positioning: the i3-10305 is bracketed by the Core i7-1068NG7 (2259, +0.2%) and Core i5-9400 (2254, +0.4%), while the i7-8559U sits near the Core i7-5775C (2224, 0% delta) and Xeon E5-4648 v3 (2227, -0.1%). These deltas are tiny, but the i3-10305’s rivals are all slightly higher-scoring, whereas the i7-8559U’s rivals are nearly identical.

The Verdict

The data is unambiguous: the Intel Core i3-10305 is the faster processor in every measurable shared workload. If raw CPU performance is the sole criterion, the i3-10305 is the clear choice, delivering a 12.1% improvement across the board. This is not a marginal win; it is a systematic advantage that will translate to faster rendering, compilation, and general multi-threaded tasks.

However, the i7-8559U is a mobile processor on Intel BGA 1356, while the i3-10305 is a desktop part on Intel Socket 1200. These are not interchangeable components. The i7-8559U is designed for laptops and compact systems where the 28 W TDP and integrated Iris Pro Plus graphics are critical. The i3-10305, with its 65 W TDP and UHD Graphics 630, is meant for desktop builds where power draw and heat dissipation are less constrained.

For a system builder with a desktop motherboard, the i3-10305 is the obvious pick—it wins every benchmark and offers a higher base clock. For a laptop buyer, the i7-8559U is the only viable option of the two, and its lower average score is the price of mobility. Neither chip has an unlocked multiplier, so overclocking is off the table for both. The i3-10305’s release date of March 2021 also makes it the newer part compared to the i7-8559U’s April 2018 launch, though both remain in active production.

Architecture Differences

The two processors come from different Intel architectures. The i3-10305 is built on Comet Lake, specifically the Comet Lake-R refresh, while the i7-8559U uses Kaby Lake, part of the Kaby Lake-U Refresh line. Both are fabricated on Intel’s 14 nm process node, but the microarchitectural changes between generations contribute to the i3’s performance lead.

The most significant architectural divergence is the base clock. The i3-10305 runs at 3.80 GHz, over a full gigahertz higher than the i7-8559U’s 2.70 GHz. Boost clocks are identical at 4.50 GHz, but the i3’s ability to sustain higher clocks under load—supported by its 65 W TDP versus 28 W—explains the consistent 12.1% benchmark delta. The i7-8559U’s lower TDP is a thermal and power constraint that the architecture cannot overcome.

Cache configurations match: both have 64 KB of L1 per core, 256 KB of L2 per core, and 8 MB of shared L3. The i7-8559U has a documented die size of 123 mm², while the i3-10305’s die size is not listed. Integrated graphics differ, with the i3 using UHD Graphics 630 and the i7 using Iris Pro Plus—the latter being a more capable GPU for a mobile part. The i3 supports PCIe Gen 3 with 16 lanes (CPU only), while the i7’s PCIe details are not provided. Both support DDR4 memory and lack ECC support.

FAQ

Q: Which processor has a higher base clock?

A: The Intel Core i3-10305 has a base clock of 3.80 GHz, while the Intel Core i7-8559U operates at 2.70 GHz. The boost clocks are identical at 4.50 GHz.

Q: Are the benchmark margins between the two consistent across tests?

A: Yes. The i3-10305 beats the i7-8559U by exactly 12.1% in all six shared Cinebench tests: R15 multi-core (788 vs 703), R15 single-core (111 vs 99), R20 multi-core (3287 vs 2933), R20 single-core (464 vs 414), R23 multi-core (7828 vs 6984), and R23 single-core (1105 vs 986).

Q: Do both processors have the same core and thread counts?

A: Yes, both have 4 cores and 8 threads, along with the same L1 (64 KB per core), L2 (256 KB per core), and L3 (8 MB shared) cache configurations.

Q: What is the TDP difference?

A: The i3-10305 has a TDP of 65 W, while the i7-8559U has a TDP of 28 W. This reflects the desktop versus mobile design intent.

Q: Which processor has better integrated graphics?

A: The i7-8559U features Iris Pro Plus graphics, while the i3-10305 uses UHD Graphics 630. The i7’s integrated solution is designed for mobile use.

Q: Are both processors still in production?

A: Yes, both the i3-10305 and the i7-8559U are listed as Active in production status.

Where Each One Wins

The Intel Core i3-10305 wins in every available benchmark comparison. Its 12.1% lead across all Cinebench tests makes it the superior choice for CPU-intensive desktop workloads such as video rendering, 3D modeling, and software compilation. The higher base clock of 3.80 GHz and 65 W TDP allow it to maintain performance under sustained load, which is critical for multi-threaded tasks. Its average benchmark score of 2264 also places it slightly ahead of the i7-8559U’s 2225, and it sits in a slightly stronger competitive position relative to its nearest rivals, all of which score within 0.8% of the i3.

The Intel Core i7-8559U wins in the context of platform suitability, though not in raw performance. As a mobile processor on Intel BGA 1356, it is the only one of the two that can be used in a laptop or ultra-compact system. Its 28 W TDP makes it feasible for thermally constrained designs, and its Iris Pro Plus integrated graphics offer a more capable GPU option than the i3’s UHD Graphics 630. The i7 also has a smaller documented die size of 123 mm², though the i3’s die size is not listed for comparison. In scenarios where mobility and power efficiency are paramount, the i7-8559U is the logical—and only—choice between the two.

Specification Differences

The two processors differ in several key specification fields. The i3-10305 has a base clock of 3.80 GHz versus the i7-8559U’s 2.70 GHz, while both share a 4.50 GHz boost clock. The TDP is 65 W for the i3 and 28 W for the i7. The socket types are entirely different: the i3 uses Intel Socket 1200, while the i7 uses Intel BGA 1356. The architecture is Comet Lake (Comet Lake-R codename) for the i3 and Kaby Lake (Kaby Lake-R) for the i7.

The i7-8559U has a documented die size of 123 mm², while the i3-10305’s die size is not listed. Memory support is DDR4 for both, but the i3 specifies a dual-channel bus with 42.7 GB/s bandwidth, whereas the i7’s memory bus and bandwidth are not provided. The i3 supports PCIe Gen 3 with 16 lanes (CPU only); the i7’s PCIe details are absent. Integrated graphics differ: UHD Graphics 630 on the i3 versus Iris Pro Plus on the i7. The i3 has a part number of SRH3K; the i7 has none listed. Release dates also diverge, with the i3 launching in March 2021 and the i7 in April 2018. Both lack ECC support and unlocked multipliers, and both are built on a 14 nm process at Intel.