Intel Core i5-6400 vs Intel Core i7-3630QM Comparison

Head-to-Head Benchmarks

The benchmark data presents a sharply split picture between these two processors. In the Cinebench suite, the Intel Core i7-3630QM is the clear victor across all six tests. The margin is remarkably consistent, hovering around 17% in every Cinebench iteration. In Cinebench R15 multicore, the i7-3630QM scores 439 against the i5-6400’s 364, a 17.1% advantage. The single-core R15 test shows a similar gap: 61 versus 51, a 16.4% lead. This pattern holds in R20, where the i7-3630QM posts 1832 multicore and 258 single-core, versus 1517 and 214 for the i5-6400 — deltas of 17.2% and 17.1% respectively. The R23 results continue the trend: 4364 versus 3614 multicore and 616 versus 510 single-core, both at a 17.2% margin.

The story flips entirely in Geekbench. Here, the i5-6400 dominates with a 48.5% lead in multicore (3134 versus 2111) and a staggering 65.6% advantage in single-core (1048 versus 633). This divergence between benchmark suites is not a minor quirk; it is a fundamental signal of how each processor handles different workloads. The Cinebench wins for the i7-3630QM are consistent and substantial, roughly one-sixth faster across the board. The Geekbench wins for the i5-6400 are even larger, nearly half again as fast in multicore and two-thirds faster in single-core.

Overall, the head-to-head tally shows 6 wins for the i7-3630QM and 2 wins for the i5-6400. Yet the magnitude of the i5-6400’s Geekbench victories outweighs the narrow consistency of the i7-3630QM’s Cinebench wins. The average benchmark score for the i5-6400 is 1307, while the i7-3630QM sits at 1289 — a difference of less than 1.5%. Both processors land in the 35th percentile of all CPUs, meaning they are statistically equivalent in overall performance as measured by this database’s aggregate metric.

Architecture Differences

The two chips come from different eras and design philosophies. The Intel Core i5-6400 is built on the Skylake architecture using a 14 nm process node, with a die size of 177 mm². The Intel Core i7-3630QM uses the older Ivy Bridge architecture on a 22 nm node, with a die size of 160 mm² and 1,480 million transistors. The i5-6400 does not list a transistor count in its specifications, but the node shrink to 14 nm is the key architectural advantage.

Both processors have 4 physical cores and 6 MB of shared L3 cache. The per-core L1 and L2 caches are identical: 64 KB and 256 KB per core respectively. The critical difference in core configuration is threading. The i5-6400 has 4 threads total, while the i7-3630QM has 8 threads thanks to Hyper-Threading. This explains the Cinebench multicore advantage for the i7-3630QM, as those tests scale with thread count.

Clock speeds differ in interesting ways. The i5-6400 has a base clock of 2.70 GHz and a boost clock of 3.30 GHz. The i7-3630QM runs a lower base clock of 2.40 GHz but a higher boost of 3.40 GHz. The i7-3630QM’s higher boost clock and extra threads give it the edge in Cinebench, where sustained multi-threaded loads benefit from both frequency and parallelism.

Memory support is a major divergence. The i5-6400 supports DDR4 memory with a dual-channel bus and a peak bandwidth of 34.1 GB/s. The i7-3630QM supports DDR3 memory, also dual-channel, but with a lower peak bandwidth of 25.6 GB/s. This 33% bandwidth advantage for the i5-6400 likely contributes to its Geekbench dominance, particularly in single-core tests where memory latency and bandwidth play a larger role.

The integrated graphics also differ: the i5-6400 pairs with HD Graphics 530, while the i7-3630QM uses Intel HD 4000. Neither processor supports ECC memory. Both use PCIe Gen 3 with 16 lanes from the CPU. The sockets are incompatible — the i5-6400 uses Intel Socket 1151, while the i7-3630QM uses Intel Socket G2 (988B) — and neither has an unlocked multiplier. The i5-6400 is a desktop part, while the i7-3630QM is a mobile part, which explains the TDP difference: 65 watts for the i5-6400 versus 45 watts for the i7-3630QM.

Where Each One Wins

The i7-3630QM wins in every Cinebench test by a consistent 16-17% margin. This suggests it is the stronger choice for rendering workloads that mimic Cinebench’s 3D rendering engine. The extra threads (8 versus 4) and higher boost clock (3.40 GHz versus 3.30 GHz) give it an edge in sustained multi-threaded rendering. Even in single-core Cinebench tests, the i7-3630QM maintains its advantage, which points to its 3.40 GHz boost clock as a decisive factor.

The i5-6400 wins decisively in Geekbench, with a 48.5% multicore and 65.6% single-core lead. Geekbench’s workloads are more diverse, including memory-intensive tasks, encryption, and compression. The i5-6400’s DDR4 memory support with 34.1 GB/s bandwidth likely drives these gains. In single-core Geekbench, the i5-6400’s 1048 score dwarfs the i7-3630QM’s 633, a gap that cannot be explained by clock speed alone — the i7-3630QM actually has a higher boost clock. The Skylake architecture’s IPC improvements and faster memory subsystem are the probable causes.

For users prioritizing rendering performance, the i7-3630QM is the clear pick. Its Cinebench wins are uniform and substantial. For users prioritizing general system responsiveness, office productivity, and workloads similar to Geekbench, the i5-6400 is far superior. The 65.6% single-core Geekbench lead is the largest margin in the entire comparison, indicating that the i5-6400 handles latency-sensitive tasks much better.

The aggregate average scores tell a nuanced story. The i5-6400’s 1307 average is just 1.4% higher than the i7-3630QM’s 1289. Both chips sit at the 35th percentile, meaning they perform at the same level as roughly one-third of all CPUs in the database. The nearest rivals for each CPU confirm their standings: the i5-6400 is bracketed by the AMD Opteron 6328 (1304, +0.2%) and AMD Athlon Gold 7220U (1311, -0.3%), while the i7-3630QM sits near the AMD Opteron 6272 (1288, +0.1%) and Intel Core i5-4670R (1286, +0.2%).

The Verdict

The data does not support a single winner. It supports two winners for two different use cases. If the workload is 3D rendering, video encoding, or any task that resembles Cinebench, the Intel Core i7-3630QM is the better processor. It wins every Cinebench test by approximately 17%, regardless of single-core or multi-core configuration. The 8 threads and 3.40 GHz boost clock deliver consistent, measurable advantages.

If the workload is general computing, web browsing, office applications, or tasks that resemble Geekbench, the Intel Core i5-6400 is the better processor. Its Geekbench wins are massive — 48.5% in multicore and 65.6% in single-core. The DDR4 memory support and Skylake architecture provide a substantial performance buffer that the older Ivy Bridge design cannot match.

For a desktop user with the ability to choose either platform, the i5-6400 offers superior memory bandwidth and modern architecture, but it loses in rendering. For a mobile user, the i7-3630QM’s 45-watt TDP makes it a viable laptop part, though its DDR3 memory limits its overall ceiling. The i5-6400’s 65-watt TDP and desktop socket make it a desktop-only option.

The average benchmark scores are nearly identical (1307 versus 1289), and both sit at the 35th percentile. This means that for the average user, the choice between these two will likely be dictated by platform compatibility and workload mix rather than raw performance. The i5-6400’s launch MSRP is $182. The i7-3630QM’s launch MSRP is $378.

FAQ

Q: Which processor is faster in Cinebench R23 multicore?

A: The Intel Core i7-3630QM scores 4364 versus the Intel Core i5-6400’s 3614, a 17.2% advantage.

Q: How large is the single-core Geekbench gap?

A: The i5-6400 scores 1048 while the i7-3630QM scores 633, giving the i5-6400 a 65.6% lead.

Q: Do both processors have the same number of cores?

A: Yes, both have 4 physical cores, but the i7-3630QM has 8 threads while the i5-6400 has 4 threads.

Q: What memory types do these CPUs support?

A: The i5-6400 supports DDR4 with 34.1 GB/s bandwidth, while the i7-3630QM supports DDR3 with 25.6 GB/s bandwidth.

Q: Which CPU has the higher boost clock?

A: The i7-3630QM has a 3.40 GHz boost clock, which is higher than the i5-6400’s 3.30 GHz boost clock.

Q: Are both processors in the same performance percentile?

A: Yes, both the i5-6400 and i7-3630QM are in the 35th percentile of all CPUs.

Specification Differences

| Specification | Intel Core i5-6400 | Intel Core i7-3630QM |

|---|---|---|

| Threads | 4 | 8 |

| Base Clock | 2.70 GHz | 2.40 GHz |

| Boost Clock | 3.30 GHz | 3.40 GHz |

| TDP | 65 W | 45 W |

| Socket | Intel Socket 1151 | Intel Socket G2 (988B) |

| Architecture | Skylake | Ivy Bridge |

| Process Node | 14 nm | 22 nm |

| Transistors | Not listed | 1,480 million |

| Die Size | 177 mm² | 160 mm² |

| Memory Support | DDR4 | DDR3 |

| Memory Bandwidth | 34.1 GB/s | 25.6 GB/s |

| Integrated Graphics | HD Graphics 530 | Intel HD 4000 |

| Market Segment | Desktop | Mobile |

| Release Date | 2015-07-01 | 2012-09-29 |

| Launch MSRP | $182 | $378 |

| Part Number | SR2L7 | SR0UX |