Intel Core i3-6100 vs Intel Core i5-5300U Comparison

The Intel Core i5-5300U and Intel Core i3-6100 are both dual-core, four-thread processors from Intel, but they target very different segments of the market. The i5-5300U is a 15-watt mobile part built on the Broadwell architecture, while the i3-6100 is a 51-watt desktop chip based on Skylake. Despite their architectural and platform differences, the benchmark data reveals a surprisingly tight competition, with the mobile chip winning the majority of head-to-head tests.

Head-to-Head Benchmarks

The most striking finding from the data is that the older, lower-power i5-5300U wins six of the seven direct benchmark comparisons. The margins are narrow but consistent. In Cinebench R15 multi-core, the i5-5300U scores 230 against the i3-6100’s 224, a 2.7% lead. That pattern repeats in Cinebench R20 multi-core, where the i5-5300U posts 960 versus 934, a 2.8% advantage. The i3-6100’s higher base clock of 3.70 GHz compared to the i5-5300U’s 2.30 GHz does not translate into a multi-core win in these tests.

The single-core results tell a similar story. In Cinebench R20 single-core, the i5-5300U scores 135 against 131, a 3.1% lead. Cinebench R23 single-core shows the same trend: 322 for the i5-5300U versus 314 for the i3-6100, a 2.5% margin. Even in Geekbench single-core, the i5-5300U edges ahead with 791 points against 785, a 0.8% victory. The only benchmark where the i3-6100 comes out on top is Geekbench multi-core, where it scores 1605 against the i5-5300U’s 1540, a 4% difference.

The win counts are decisive: 6 wins for the i5-5300U and just 1 for the i3-6100. Yet the overall average benchmark scores are nearly identical, with the i5-5300U at 895 and the i3-6100 at 888, a difference of only 0.7%. This suggests that while the i5-5300U excels in Cinebench workloads, the i3-6100’s single Geekbench multi-core win is substantial enough to nearly close the gap in the aggregate score.

Architecture Differences

The two processors come from different Intel microarchitectures and are built for different sockets. The i5-5300U is a Broadwell-U part, manufactured on a 14 nm process with 1,300 million transistors on an 82 mm² die. It uses the Intel BGA 1168 socket and is classified as a mobile processor. The i3-6100 is Skylake, also on a 14 nm node, but with 1,400 million transistors on a much larger 150 mm² die. It uses the Intel Socket 1151 and is a desktop part.

Cache configurations differ as well. Both have 64 KB of L1 and 256 KB of L2 per core, but the i5-5300U has 3 MB of shared L3 cache, while the i3-6100 has 4 MB. The larger L3 cache on the i3-6100 might explain its Geekbench multi-core advantage, but it does not appear to help in Cinebench tests. The i5-5300U compensates with a boost clock of 2.90 GHz, a feature the i3-6100 lacks entirely; the i3-6100 has no boost clock, running at a fixed 3.70 GHz.

Memory support is another clear divergence. The i5-5300U supports DDR3 memory with dual-channel bandwidth of 25.6 GB/s. The i3-6100 supports DDR4 with dual-channel bandwidth of 34.1 GB/s, a 33% higher theoretical memory bandwidth. The PCIe interface also differs: the i5-5300U offers Gen 2 with 12 lanes, while the i3-6100 provides Gen 3 with 16 lanes. Neither processor supports ECC memory, and both are multiplier-locked.

Integrated graphics are different as well. The i5-5300U carries Intel HD 5500, while the i3-6100 has Intel HD 530. The production statuses also differ: the i5-5300U is end-of-life, whereas the i3-6100 remains active. The i5-5300U launched in February 2015 with a launch MSRP of $315, while the i3-6100 launched later in August 2015.

The Verdict

The data presents a counterintuitive picture. The i5-5300U, a low-power mobile chip with a 15-watt TDP, outperforms the desktop i3-6100 in nearly every Cinebench test and in Geekbench single-core. The i3-6100 only wins in Geekbench multi-core. This suggests that for most CPU-bound tasks, the i5-5300U delivers equivalent or slightly better performance, despite its lower base clock and mobile pedigree.

However, context matters. The i5-5300U is a mobile part meant for laptops, while the i3-6100 is a desktop processor. The i3-6100's advantage in Geekbench multi-core, combined with its newer DDR4 memory support and higher PCIe lane count, positions it as the more capable platform for systems that need faster memory bandwidth and more expansion. The i5-5300U’s 15-watt TDP versus the i3-6100’s 51-watt TDP makes the i5-5300U far more suitable for battery-powered devices, but that efficiency comes with a socket that is not upgradeable.

The aggregate scores are nearly tied: 895 for the i5-5300U and 888 for the i3-6100, with both sitting at the 24th percentile of all CPUs. The i5-5300U’s nearest rivals include the Pentium G4600T and AMD PRO A10-8770E at identical average scores, while the i3-6100 matches the Xeon X5550. These are not high-performance processors by modern standards, but the i5-5300U’s consistent wins show that the mobile chip is not at a disadvantage in raw compute.

FAQ

Q: Which processor has a higher base clock speed?

A: The Intel Core i3-6100 has a base clock of 3.70 GHz, while the i5-5300U has a base clock of 2.30 GHz. The i3-6100 does not have a boost clock, whereas the i5-5300U can boost up to 2.90 GHz.

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

A: The i5-5300U scores 2287, which is 2.7% higher than the i3-6100’s 2226. This follows the pattern seen in other Cinebench tests, where the i5-5300U consistently leads.

Q: Does the i3-6100 win any benchmark?

A: Yes, the i3-6100 wins the Geekbench multi-core test with a score of 1605, which is 4% higher than the i5-5300U’s 1540. This is the only head-to-head test the i3-6100 wins.

Q: What are the memory bandwidth capabilities of each?

A: The i5-5300U supports DDR3 memory with a bandwidth of 25.6 GB/s, while the i3-6100 supports DDR4 memory with a bandwidth of 34.1 GB/s. Both use dual-channel memory buses.

Q: Are both processors on the same manufacturing process?

A: Yes, both are built on a 14 nm process. However, the i5-5300U has 1,300 million transistors on an 82 mm² die, while the i3-6100 has 1,400 million transistors on a 150 mm² die.

Q: What is the difference in thermal design power?

A: The i5-5300U has a TDP of 15 watts, which is significantly lower than the i3-6100’s 51 watts. This makes the i5-5300U more efficient for mobile use.

Where Each One Wins

The i5-5300U is the winner in Cinebench workloads, taking R15, R20, and R23 multi-core tests, plus R20 and R23 single-core tests. It also wins in Geekbench single-core. This makes it the stronger choice for applications that rely on short, single-threaded bursts or that are optimized for Cinebench-style rendering. Its 15-watt TDP and mobile socket also make it the only practical choice for laptops or fanless designs, though the data does not cover battery life or thermal behavior.

The i3-6100 wins only in Geekbench multi-core, where it leads by 4%. This suggests that in certain multi-threaded workloads, the i3-6100’s higher fixed clock speed and larger 4 MB L3 cache can overcome the i5-5300U’s architectural advantages. Its DDR4 memory support and Gen 3 PCIe with 16 lanes also make it a better foundation for a desktop system that needs faster memory and more expansion options. For a user building a low-cost desktop, the i3-6100 offers a clear platform advantage, even if the raw CPU scores are nearly identical.

Specification Differences

The two processors differ in several key specifications. The i5-5300U has a base clock of 2.30 GHz with a boost clock of 2.90 GHz, while the i3-6100 has a base clock of 3.70 GHz and no boost. The i5-5300U has a TDP of 15 watts, versus 51 watts for the i3-6100. Their sockets are incompatible: the i5-5300U uses Intel BGA 1168, and the i3-6100 uses Intel Socket 1151.

The architectures are different, with the i5-5300U being Broadwell (Broadwell-U) and the i3-6100 being Skylake. The i5-5300U has 1,300 million transistors on an 82 mm² die, while the i3-6100 has 1,400 million on 150 mm². L3 cache is 3 MB on the i5-5300U and 4 MB on the i3-6100. Memory support differs: DDR3 for the i5-5300U with 25.6 GB/s bandwidth, and DDR4 for the i3-6100 with 34.1 GB/s. PCIe is Gen 2 with 12 lanes on the i5-5300U, versus Gen 3 with 16 lanes on the i3-6100. Integrated graphics are Intel HD 5500 on the i5-5300U and Intel HD 530 on the i3-6100. The market segments also differ: mobile for the i5-5300U and desktop for the i3-6100. Production status: the i5-5300U is end-of-life, while the i3-6100 is active. The i5-5300U has a launch MSRP of $315; the i3-6100 has no listed launch MSRP.