CPU Comparison

The Intel Core i5-6400 and AMD Opteron 6272 represent two fundamentally different approaches to processor design, separated by roughly four years of architectural evolution. The data shows a clear, consistent winner across every benchmark in the head-to-head comparison, yet the full picture requires understanding the context of each chip’s intended role. The i5-6400 is a 4-core Skylake desktop part built on a 14 nm process, while the Opteron 6272 is a 16-core Bulldozer server processor on 32 nm. Despite having four times the core count, the Opteron’s advantage in multi-threaded tests is substantial but not proportional, and it also wins single-threaded tests, which runs counter to typical expectations for a server chip of its generation.

FAQ

Q: Which processor wins the most benchmark comparisons?

A: The AMD Opteron 6272 wins all six head-to-head benchmark comparisons, including every Cinebench R15, R20, and R23 test in both single-core and multi-core variants.

Q: How large is the performance gap in multi-core workloads?

A: The Opteron 6272 leads by roughly 18.7% to 18.9% across all Cinebench multi-core tests. Specifically, it scores 448 versus 364 in R15, 1870 versus 1517 in R20, and 4454 versus 3614 in R23.

Q: Does the Intel chip win any single-core tests?

A: No. The Opteron 6272 also wins every single-core test, with deltas of -19% in R15, -18.6% in R20, and -18.8% in R23 relative to the i5-6400.

Q: What is the average benchmark score for each processor?

A: The Intel Core i5-6400 has an average benchmark score of 1307, while the AMD Opteron 6272 scores 1288. This puts them within 1.5% of each other, despite the Opteron’s dominance in the specific Cinebench tests.

Q: How do their overall performance percentiles compare?

A: Both processors sit at exactly the 35th percentile among all CPUs, indicating they are statistically equivalent in overall standing within the database.

Q: What are their launch MSRPs?

A: The Intel Core i5-6400 has a launch MSRP of $182, while the AMD Opteron 6272 has a launch MSRP of $523.

Architecture Differences

The architectural chasm between these two chips is stark, starting with the process node. Intel’s i5-6400 is fabricated on a 14 nm process at Intel’s foundry, while the Opteron 6272 uses a 32 nm process from GlobalFoundries. This process advantage gives the Intel part a significantly smaller die size of 177 mm², whereas the AMD chip uses two dies totaling 2x 315 mm². The transistor count tells a similar story: the Opteron packs 2,400 million transistors, while the i5-6400’s count is not listed in the data.

Core configuration is where the designs diverge most sharply. The i5-6400 has 4 cores and 4 threads, with 64 KB of L1 cache per core and 256 KB of L2 cache per core, plus a shared 6 MB L3 cache. The Opteron 6272 has 16 cores and 16 threads, organized in a Bulldozer module layout with 768 KB of L1 cache total, 2 MB of L2 per module, and 8 MB of L3 per die. This means the Opteron’s cache hierarchy is designed for throughput across many threads, not for low latency per thread.

Clock speeds also reflect their different missions. The i5-6400 runs at a 2.70 GHz base clock with a 3.30 GHz boost, while the Opteron 6272 runs at a 2.10 GHz base with a 3.00 GHz boost. The Intel chip’s higher clocks are typical for a desktop part where single-thread responsiveness matters. Memory support further separates them: the i5-6400 uses DDR4 in dual-channel configuration with 34.1 GB/s bandwidth and no ECC support, whereas the Opteron uses DDR3 in quad-channel with 51.2 GB/s bandwidth and ECC support. The Opteron also offers more PCIe lanes, with Gen 2 support, while the i5-6400 has Gen 3 with 16 lanes from the CPU.

Integrated graphics are exclusive to the Intel part, which includes HD Graphics 530, while the Opteron has none. The Opteron is built for server/ workstation duties, while the i5-6400 targets the desktop market. Both are end-of-life products, but the Opteron was released in November 2011, while the i5-6400 came in July 2015.

Head-to-Head Benchmarks

The benchmark data is unambiguous: the AMD Opteron 6272 wins every single test, with a remarkably consistent margin. In Cinebench R15 multi-core, the Opteron scores 448 against the i5-6400’s 364, a delta of -18.7% for the Intel part. The single-core R15 result shows the Opteron at 63 versus 51, a -19% gap. These margins are nearly identical across all tests, suggesting a systematic performance advantage rather than workload-specific behavior.

Moving to Cinebench R20, the pattern holds. The Opteron’s multi-core score of 1870 beats the i5-6400’s 1517 by -18.9%. In single-core, the Opteron’s 263 outperforms the i5-6400’s 214 by -18.6%. The most recent Cinebench R23 test confirms the trend: multi-core scores are 4454 for the Opteron versus 3614 for the i5-6400 (-18.9%), and single-core scores are 628 versus 510 (-18.8%).

The consistency of these deltas, all falling between -18.6% and -19%, is notable. It implies that the Opteron’s advantage is not tied to any specific instruction set or cache behavior but is a general characteristic of the chip’s design. Despite having four times the cores, the Opteron does not achieve four times the multi-core throughput. The i5-6400’s newer architecture and higher base clock of 2.70 GHz versus 2.10 GHz help close the gap, but the raw core count advantage still carries the Opteron to victory in every test. The wins are decisive, but the margins are modest given the core disparity.

Specification Differences

The two processors differ on nearly every specification field. The i5-6400 has 4 cores and 4 threads, while the Opteron 6272 has 16 cores and 16 threads. Base clocks are 2.70 GHz versus 2.10 GHz, and boost clocks are 3.30 GHz versus 3.00 GHz. Thermal design power is dramatically different: 65 watts for the Intel part versus 115 watts for the AMD part. Sockets are incompatible, Intel Socket 1151 versus AMD Socket G34.

Process technology separates them at 14 nm versus 32 nm, with foundries listed as Intel versus GlobalFoundries. Die size is 177 mm² versus 2x 315 mm², and the Opteron’s transistor count of 2,400 million is the only figure listed. Cache configurations are entirely different: the i5-6400 uses per-core L1 and L2 caches with a shared L3, while the Opteron uses a total L1, per-module L2, and per-die L3. Memory support is DDR4 dual-channel versus DDR3 quad-channel, with bandwidths of 34.1 GB/s versus 51.2 GB/s. ECC memory is unsupported on the Intel chip and supported on the AMD chip. PCIe generation is Gen 3 versus Gen 2. Integrated graphics are present only on the i5-6400. Market segments are Desktop versus Server/Workstation. Release dates are July 2015 versus November 2011. Launch MSRP is $182 versus $523. Part numbers are SR2L7 versus OS6272WKTGGGU.

The Verdict

The data directs different buyers to different chips. The AMD Opteron 6272 is the clear performance winner in every benchmark recorded, with a consistent 18.6% to 19% lead across all Cinebench tests, both single-core and multi-core. For workloads that rely on Cinebench-style rendering, the Opteron is the better choice. Its 16 cores and 16 threads, combined with quad-channel DDR3 memory providing 51.2 GB/s bandwidth, give it a raw throughput edge that the i5-6400 cannot overcome despite its higher clock speeds and newer architecture.

However, the i5-6400 has its own strengths that the data supports. It runs at 65 watts TDP versus 115 watts, which is a substantial efficiency advantage. It uses newer DDR4 memory and has integrated graphics, which the Opteron lacks entirely. Its 14 nm process and smaller die size suggest lower manufacturing complexity. For a desktop user who values lower power draw, integrated graphics, and modern memory support, the i5-6400 is the logical pick, even if it loses on raw benchmark scores.

The overall percentile rankings are identical at 35%, and the average benchmark scores are nearly the same (1307 versus 1288). This indicates that in the broader database, these two chips perform at a similar level overall. The nearest rivals for the i5-6400 include the AMD Opteron 6328 with a delta of 0.2%, while the Opteron 6272’s nearest rival is the Intel Core i7-3630QM with a delta of -0.1%. These close margins underscore that neither chip is dramatically better than the other in aggregate, despite the Opteron’s clean sweep in the head-to-head.

Ultimately, the Opteron 6272 wins on raw performance metrics, making it the choice for multi-threaded server workloads where ECC memory and high core counts matter more than power efficiency. The i5-6400 is the better option for a desktop build where its lower TDP, integrated graphics, and modern platform features outweigh the benchmark deficit. The data shows no ambiguity in the winner, but it also shows that the loser has clear advantages in other dimensions.