Intel Core i5-6400 vs Intel Core i7-3770T Comparison

The Intel Core i7-3770T and Intel Core i5-6400 are two desktop processors from different eras, and the benchmark data reveals a stark split in their strengths. The i7-3770T dominates in rendering workloads, while the i5-6400 is decisively ahead in Geekbench tests. The i7-3770T wins 6 of the 8 head-to-head comparisons, but the i5-6400’s two wins are substantial, with the overall average benchmark scores being nearly identical: 1314 for the i7-3770T versus 1307 for the i5-6400. The data indicates that the i7-3770T is the better choice for multi-threaded content creation, whereas the i5-6400 excels in general system responsiveness and single-threaded tasks.

Where Each One Wins

The i7-3770T is the clear victor in all Cinebench tests, which measure 3D rendering performance. Across Cinebench R15, R20, and R23, the i7-3770T holds a consistent advantage of approximately 27.5% over the i5-6400 in both multi-core and single-core runs. Specifically, the i7-3770T scores 464 versus 364 in Cinebench R15 multi-core, and 4611 versus 3614 in Cinebench R23 multi-core. This pattern suggests that the i7-3770T’s architecture, particularly its 8 threads, provides a significant edge in rendering engines that scale with thread count.

The i5-6400 wins decisively in the Geekbench tests, which are more representative of everyday applications and memory-bound tasks. In Geekbench multi-core, the i5-6400 scores 3134 against the i7-3770T’s 1916, a difference of 38.9%. The single-core gap is even larger, with the i5-6400 scoring 1048 versus 592, a 43.5% advantage. These results indicate that the i5-6400 offers far superior performance in workloads that rely on per-core efficiency and faster memory access, such as web browsing, office applications, and software compilation.

The data points to a clear use-case split: the i7-3770T is optimized for parallel processing in professional rendering, while the i5-6400 is better suited for responsive, low-latency tasks where individual core speed and memory bandwidth matter more. The i5-6400’s support for DDR4 memory, compared to the i7-3770T’s DDR3, is a likely contributor to its Geekbench dominance. Users should select based on whether their primary workload is threaded rendering or general-purpose computing.

Architecture Differences

The two processors are built on fundamentally different architectures and process nodes. The i7-3770T uses the Ivy Bridge architecture on a 22 nm process, fabricated by Intel with 1,400 million transistors on a 160 mm² die. In contrast, the i5-6400 uses the newer Skylake architecture on a 14 nm process, with a die size of 177 mm². While the i5-6400 does not have a listed transistor count, its smaller process node allows for higher clock speeds at similar power levels.

The core configuration is a major differentiator. The i7-3770T has 4 cores and 8 threads, leveraging Hyper-Threading, while the i5-6400 has 4 cores and 4 threads without Hyper-Threading. This explains the i7-3770T’s superior multi-threaded rendering scores. The i7-3770T also has a larger L3 cache at 8 MB shared, compared to the i5-6400’s 6 MB shared. However, the i5-6400 has a higher base clock of 2.70 GHz versus 2.50 GHz, but a lower boost clock of 3.30 GHz versus 3.70 GHz.

Memory support differs significantly. The i7-3770T supports DDR3 memory, while the i5-6400 supports DDR4, with a listed memory bandwidth of 34.1 GB/s for the i5-6400. The i7-3770T does not have a listed memory bandwidth figure. Both processors use dual-channel memory buses and support PCIe Gen 3 with 16 lanes from the CPU. The integrated graphics also differ: the i7-3770T has Intel HD 4000, while the i5-6400 has HD Graphics 530. The i5-6400 is marked as end-of-life, while the i7-3770T’s production status is not specified.

Head-to-Head Benchmarks

The most striking result is the consistent 27.5% to 27.6% lead for the i7-3770T in all six Cinebench tests. In Cinebench R15 multi-core, the i7-3770T scores 464 against the i5-6400’s 364, a 27.5% win. The single-core R15 result is identical in margin: 65 versus 51, also a 27.5% difference. This pattern repeats in Cinebench R20, where the i7-3770T leads 1936 to 1517 (27.6% delta), and in Cinebench R23, where it leads 4611 to 3614 (27.6% delta).

The i5-6400’s wins are much larger in percentage terms. In Geekbench multi-core, the i5-6400 scores 3134 against the i7-3770T’s 1916, a 38.9% advantage. The single-core Geekbench test is even more lopsided: the i5-6400’s 1048 score beats the i7-3770T’s 592 by 43.5%. These Geekbench numbers are notable because they show that despite the i7-3770T’s higher thread count and larger cache, the i5-6400’s newer architecture and DDR4 memory support translate into a massive real-world performance advantage in tasks that favor memory latency and per-core throughput.

Looking at the average benchmark scores, the i7-3770T averages 1314, while the i5-6400 averages 1307. This near-tie masks the extreme variance in individual tests. The i7-3770T’s wins are narrow in terms of absolute score differences (e.g., 100 points in R15 multi-core), but the i5-6400’s wins are wide (over 1000 points in Geekbench multi-core). The data suggests that the i5-6400’s strengths are more impactful for typical desktop use, even though the i7-3770T wins more tests overall.

The Verdict

The data supports a clear verdict: pick the Intel Core i7-3770T if your primary applications are multi-threaded rendering workloads like Cinebench. The i7-3770T is 27.6% faster than the i5-6400 in Cinebench R23 multi-core, and similar margins hold across all Cinebench versions. Its 8 threads and 8 MB L3 cache give it a decisive edge in content creation, 3D modeling, and video encoding that utilize all available threads.

Pick the Intel Core i5-6400 if you prioritize general system performance, as measured by Geekbench. The i5-6400 is 43.5% faster in Geekbench single-core and 38.9% faster in Geekbench multi-core. This makes it the better choice for everyday computing, productivity suites, and gaming, where single-thread performance and fast memory access are critical. The i5-6400’s support for DDR4 memory with 34.1 GB/s bandwidth is a key advantage over the i7-3770T’s DDR3 support.

The i7-3770T is not a bad processor—it holds a 35th percentile ranking among all CPUs, and its average score is nearly identical to the i5-6400’s. However, the i5-6400’s wins are far more impactful for mainstream users. The fact that the i5-6400 was launched with an MSRP of $182 (which may be stated once) and is end-of-life suggests it was a mainstream part, while the i7-3770T was a low-power flagship of its generation. For most users, the i5-6400’s Geekbench performance will be more noticeable in daily use.

FAQ

Q: Which processor is faster in Cinebench R23 multi-core?

A: The Intel Core i7-3770T is faster, scoring 4611 compared to the Intel Core i5-6400’s 3614, a 27.6% advantage.

Q: How big is the single-core Geekbench difference?

A: The Intel Core i5-6400 wins by 43.5%, scoring 1048 versus the Intel Core i7-3770T’s 592.

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

A: Yes, both have 4 cores. However, the i7-3770T has 8 threads, while the i5-6400 has 4 threads.

Q: What memory types do they support?

A: The Intel Core i7-3770T supports DDR3 memory, while the Intel Core i5-6400 supports DDR4 memory.

Q: Which CPU has a larger L3 cache?

A: The Intel Core i7-3770T has 8 MB of shared L3 cache, compared to the Intel Core i5-6400’s 6 MB.

Q: What is the overall benchmark percentile for these processors?

A: Both the Intel Core i7-3770T and the Intel Core i5-6400 are ranked in the 35th percentile among all CPUs.

Specification Differences

| Specification | Intel Core i7-3770T | Intel Core i5-6400 |

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

| Threads | 8 | 4 |

| Base Clock | 2.50 GHz | 2.70 GHz |

| Boost Clock | 3.70 GHz | 3.30 GHz |

| TDP | 45 W | 65 W |

| Socket | Intel Socket 1155 | Intel Socket 1151 |

| Architecture | Ivy Bridge | Skylake |

| Process Node | 22 nm | 14 nm |

| Die Size | 160 mm² | 177 mm² |

| L3 Cache | 8 MB (shared) | 6 MB (shared) |

| Memory Support | DDR3 | DDR4 |

| Memory Bandwidth | Not listed | 34.1 GB/s |

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

| Production Status | Not listed | End-of-life |

| Release Date | 2012-04-28 | 2015-07-01 |

| Launch MSRP | Not listed | $182 |

| Part Number | SR0PQ | SR2L7 |

The i7-3770T has a lower TDP of 45 W versus 65 W, and a smaller die size. The i5-6400 has a higher base clock but lower boost clock. The i7-3770T lacks a listed memory bandwidth figure, while the i5-6400 has a specified 34.1 GB/s. Both processors have 4 cores, 64 KB L1 and 256 KB L2 cache per core, dual-channel memory buses, PCIe Gen 3 with 16 lanes, and do not support ECC memory. Neither has an unlocked multiplier.