Intel Atom x7425E vs Intel Core i5-6400 Comparison

Head-to-Head Benchmarks

The benchmark comparison between the Intel Core i5-6400 and the Intel Atom x7425E is decisively one-sided. Across all six recorded Cinebench tests, the Intel Atom x7425E wins every single matchup. The data shows a consistent performance advantage for the Atom part, with delta percentages hovering around minus 17.7 to minus 18 percent relative to the Core i5-6400. This means the Atom x7425E is roughly 17 to 18 percent faster in every rendering workload recorded, whether single-threaded or multi-threaded.

Starting with Cinebench R15, the Atom x7425E scores 443 points in the multicore test against 364 points for the Core i5-6400, a delta of minus 17.8 percent. In the single-core R15 test, the Atom scores 62 versus 51, a minus 17.7 percent difference. The pattern holds in Cinebench R20: the Atom posts 1849 multicore points against 1517 for the i5-6400, a minus 18 percent gap, and 260 single-core points against 214, again minus 17.7 percent. The newest Cinebench R23 test shows the same story: the Atom x7425E achieves 4403 multicore points versus 3614 for the i5-6400 (minus 17.9 percent), and 621 single-core points versus 510 (minus 17.9 percent).

It is worth remembering the Core i5-6400 does not have a recorded Geekbench result in the head-to-head data, while the Atom x7425E also lacks a Geekbench entry in this specific comparison. The head-to-head section only includes Cinebench iterations, and in every one of those six tests, the Atom x7425E is the winner. The wins tally is 6 for the Atom and 0 for the Core i5-6400.

The magnitude of the advantage is remarkably uniform. The delta percentages are nearly identical across all tests, ranging from minus 17.7 to minus 18.0. This consistency suggests that the performance difference is not workload-dependent but rather a fundamental architectural edge. The Atom x7425E, despite its lower base clock of 1.50 GHz, reaches a boost clock of 3.40 GHz, which is slightly higher than the Core i5-6400's 3.30 GHz boost. The higher boost clock, combined with the newer Gracemont cores, appears to deliver a clear and repeatable victory in these Cinebench workloads.

When placed in the broader database context, both processors sit at the 35th percentile among all CPUs. The Core i5-6400 has an average benchmark score of 1307, while the Atom x7425E averages 1273. This is an interesting nuance: despite losing every head-to-head Cinebench test, the Core i5-6400 has a slightly higher average score across all recorded benchmarks. The nearest rivals for the i5-6400 include the AMD Opteron 6328 (1304, delta 0.2 percent), the AMD Athlon Gold 7220U (1311, delta minus 0.3 percent), and the Intel Core i7-3770T (1314, delta minus 0.5 percent). The Atom x7425E's nearest rivals include the Intel Core i5-4430S (1274, delta 0 percent) and the Intel Core i5-4670T (1271, delta 0.2 percent). This indicates that the Atom x7425E sits in the same performance class as older desktop Core i5 parts, while the Core i5-6400 sits slightly above that class in the overall average.

The Verdict

The recorded data is unambiguous: for any workload represented by Cinebench R15, R20, or R23, the Intel Atom x7425E is the faster processor. It wins all six head-to-head tests with a consistent margin of approximately 18 percent. Users who prioritize rendering performance in these specific benchmarks should select the Atom x7425E without hesitation.

However, the broader database picture adds a layer of nuance. The Core i5-6400 holds a higher average benchmark score (1307 versus 1273) and a better percentile ranking relative to its nearest rivals. Its nearest competitors include the AMD Opteron 6328 and AMD Athlon Gold 7220U, both of which are within 0.3 percent of its score. The Atom x7425E, by contrast, is matched almost exactly by the Intel Core i5-4430S (delta 0 percent) and slightly outperforms the Intel Core i5-4670T (delta 0.2 percent). This suggests that while the Atom wins the Cinebench suite, the Core i5-6400 may hold its own in other benchmark categories not recorded in this head-to-head comparison.

The production status is also a differentiator. The Core i5-6400 is end-of-life, while the Atom x7425E is active and currently available. For new system designs, the Atom x7425E is the only sensible choice from a lifecycle perspective. The Atom also offers a dramatically lower thermal design power: 12 watts versus 65 watts for the Core i5-6400. This makes the Atom far more suitable for compact, fanless, or power-constrained mobile designs.

The verdict from the data is straightforward: the Atom x7425E is the superior performer in Cinebench workloads, has a lower power envelope, and is still in active production. The Core i5-6400 retains a slight edge in overall average benchmark score, but that edge is not reflected in any of the six head-to-head tests. For anyone choosing between these two based on the recorded measurements, the Atom x7425E is the clear winner.

Architecture Differences

The two processors come from fundamentally different architectural lineages. The Core i5-6400 is built on the Skylake architecture, released in 2015, while the Atom x7425E uses the Alder Lake-N architecture with Gracemont cores, released in 2023. The process nodes reflect this generational gap: the Core i5-6400 is fabricated on Intel's 14 nm node, while the Atom x7425E uses the 10 nm node. Both are manufactured by Intel.

The cache hierarchies differ significantly. The Core i5-6400 has 64 KB of L1 cache per core and 256 KB of L2 cache per core, with 6 MB of shared L3 cache. The Atom x7425E has 96 KB of L1 cache per core, but its L2 cache is organized differently: 2 MB shared across all cores, and it also has 6 MB of shared L3 cache. This means the Atom has more L1 cache per core but less dedicated L2 per core, relying instead on a shared L2 pool.

The integrated graphics solutions are also different. The Core i5-6400 includes HD Graphics 530, while the Atom x7425E features UHD Graphics with 24 execution units. The Atom's graphics are newer and part of the Alder Lake-N platform, though the recorded data does not include any graphics benchmarks to compare them directly.

The memory interfaces are a notable architectural divergence. The Core i5-6400 supports DDR4 memory with a dual-channel bus, achieving a recorded memory bandwidth of 34.1 GB/s. The Atom x7425E supports both DDR4 and DDR5, but uses a single-channel bus. Despite the narrower channel, the Atom's memory bandwidth is recorded at 38.4 GB/s, which is higher than the Core i5-6400's 34.1 GB/s. This is an unusual result: a single-channel implementation on a newer platform can exceed the bandwidth of an older dual-channel design, likely due to the higher data rates of DDR5 support.

PCIe connectivity also differs. The Core i5-6400 provides PCIe Gen 3 with 16 lanes from the CPU, while the Atom x7425E provides PCIe Gen 3 with 9 lanes. The Atom has fewer lanes, which limits expansion options, but this is consistent with its mobile, low-power positioning.

Specification Differences

The two processors differ in several key specification fields. The most obvious is the socket: the Core i5-6400 uses Intel Socket 1151, while the Atom x7425E uses Intel BGA 1264. The Core i5-6400 is a desktop part, while the Atom x7425E is a mobile part, reflecting their intended use cases.

Base clock speeds are dramatically different: the Core i5-6400 runs at 2.70 GHz, while the Atom x7425E has a base clock of 1.50 GHz. However, the boost clocks are much closer: 3.30 GHz for the Core i5-6400 and 3.40 GHz for the Atom x7425E. The Atom's higher boost clock helps explain its superior Cinebench performance.

Thermal design power is a major differentiator: the Core i5-6400 is rated at 65 watts, while the Atom x7425E is rated at just 12 watts. This is a more than fivefold difference in power draw, making the Atom far more efficient.

Memory support differs: the Core i5-6400 supports only DDR4, while the Atom x7425E supports both DDR4 and DDR5. The memory bus is dual-channel for the Core i5-6400 and single-channel for the Atom, yet the Atom's recorded memory bandwidth is higher at 38.4 GB/s versus 34.1 GB/s.

The launch MSRP for the Core i5-6400 was $182, while the Atom x7425E launched at $58. The release dates are also far apart: the Core i5-6400 was released in July 2015, while the Atom x7425E was released in January 2023. Production status differs as well: the Core i5-6400 is end-of-life, while the Atom x7425E is active. Neither processor has an unlocked multiplier.

FAQ

Q: Which processor is faster in Cinebench R23 multicore?

A: The Intel Atom x7425E scores 4403 points versus 3614 points for the Intel Core i5-6400, a delta of minus 17.9 percent. The Atom wins by a clear margin.

Q: Does the Core i5-6400 win any benchmark in the head-to-head comparison?

A: No. The Intel Atom x7425E wins all six recorded tests: Cinebench R15 multicore and single-core, Cinebench R20 multicore and single-core, and Cinebench R23 multicore and single-core. The wins tally is 6 for the Atom and 0 for the Core i5-6400.

Q: How do the average benchmark scores compare?

A: The Core i5-6400 has an average benchmark score of 1307, while the Atom x7425E averages 1273. Both sit at the 35th percentile among all CPUs. The Core i5-6400's nearest rival is the AMD Opteron 6328 with a delta of 0.2 percent, while the Atom x7425E's nearest rival is the Intel Core i5-4430S with a delta of 0 percent.

Q: What are the power consumption differences?

A: The Core i5-6400 has a thermal design power of 65 watts, while the Atom x7425E is rated at just 12 watts. This makes the Atom significantly more power-efficient.

Q: Which processor supports DDR5 memory?

A: Only the Intel Atom x7425E supports DDR5, along with DDR4. The Core i5-6400 supports only DDR4. Despite the Atom's single-channel memory bus, its recorded memory bandwidth is 38.4 GB/s, higher than the Core i5-6400's 34.1 GB/s over dual-channel.

Q: What is the production status of each processor?

A: The Core i5-6400 is end-of-life, while the Atom x7425E is active and currently in production. The Core i5-6400 was released in 2015, and the Atom x7425E was released in 2023.