AMD Opteron 6272 vs Intel Core i5-2500K Comparison

Where Each One Wins

The benchmark results present an unusual picture: the AMD Opteron 6272 wins every recorded head-to-head test, yet the two processors land in the same percentile bracket. The Opteron 6272 claims victory in all five shared Cinebench workloads, with margins ranging from 26.4% to 26.6% depending on the specific test. The Intel Core i5-2500K, by contrast, does not secure a single win in the recorded head-to-head data. This does not mean the Core i5-2500K is without merit; rather, the available benchmark suite is entirely Cinebench-based, which heavily favors the Opteron's massive core count.

The Opteron 6272's wins are consistent across both multi-core and single-core tests. In multi-core workloads, the 16-core processor leverages its physical core advantage to outpace the 4-core Core i5-2500K by a significant margin. The single-core results are more surprising, as the Opteron 6272 also leads there, despite its lower base and boost clocks. This suggests that the Cinebench single-threaded workload responds well to the Opteron's architecture, or that the Core i5-2500K's recorded single-core scores are limited by other factors in the test environment.

The use-case split is therefore clear: for heavily threaded workloads, the Opteron 6272 is the decisive choice. For lightly threaded tasks, the data still favors the Opteron in these specific Cinebench tests, but the margin is identical to the multi-core delta, which is unusual. The Core i5-2500K's strengths lie elsewhere, particularly in its higher clock speeds, unlocked multiplier, and integrated graphics, none of which appear in the benchmark results. The database shows no scenario where the Core i5-2500K outperforms the Opteron in the recorded tests.

Specification Differences

The two processors differ in nearly every fundamental specification. The Opteron 6272 offers 16 cores and 16 threads, while the Core i5-2500K provides 4 cores and 4 threads. Base clocks favor the Intel part: 3.30 GHz versus 2.10 GHz for the AMD. Boost clocks also favor Intel: 3.70 GHz versus 3.00 GHz. The Opteron has a higher thermal design power at 115 watts, compared to 95 watts for the Core i5.

Memory configurations diverge sharply. The Opteron 6272 supports quad-channel DDR3 with a memory bandwidth of 51.2 GB/s, while the Core i5-2500K uses dual-channel DDR3 with 25.6 GB/s. The Opteron supports ECC memory; the Core i5 does not. Both use PCIe Gen 2, but the Core i5 provides 16 lanes on the CPU only, while the Opteron's PCIe configuration is not specified in the same detail.

Cache structures are entirely different. The Opteron 6272 has 768 KB of L1 cache, 2 MB of L2 cache per module, and 8 MB of L3 cache per die. The Core i5-2500K has 64 KB of L1 cache per core, 256 KB of L2 cache per core, and 6 MB of shared L3 cache. The Opteron uses a dual-die design with a die size of 2x 315 mm², while the Core i5 uses a single 216 mm² die. Transistor counts also differ: 2,400 million for the Opteron versus 1,160 million for the Core i5.

The Opteron 6272 targets the server and workstation segment with an AMD Socket G34, while the Core i5-2500K is a desktop part on Intel Socket 1155. The Core i5 includes integrated graphics (Intel HD 3000), while the Opteron has none. The Core i5 has an unlocked multiplier; the Opteron does not. Both are end-of-life products, with the Core i5 released approximately ten months earlier.

FAQ

Q: Which processor has more cores?

A: The AMD Opteron 6272 has 16 cores and 16 threads, compared to 4 cores and 4 threads on the Intel Core i5-2500K.

Q: Do both processors support ECC memory?

A: No. The Opteron 6272 supports ECC memory, while the Core i5-2500K does not.

Q: What is the memory bandwidth difference?

A: The Opteron 6272 provides 51.2 GB/s via quad-channel DDR3, exactly double the 25.6 GB/s of the Core i5-2500K's dual-channel DDR3.

Q: Which processor has a higher boost clock?

A: The Core i5-2500K boosts to 3.70 GHz, while the Opteron 6272 boosts to 3.00 GHz.

Q: Does either processor include integrated graphics?

A: The Core i5-2500K includes Intel HD 3000 integrated graphics. The Opteron 6272 has no integrated graphics.

Q: What are the average benchmark scores for each?

A: The Opteron 6272 has an average benchmark score of 1288, while the Core i5-2500K averages 1329. The Core i5's nearest rival, the Intel Core i5-4460S, scores 1330, which is 0.1% higher.

Head-to-Head Benchmarks

The recorded head-to-head data shows a clean sweep for the AMD Opteron 6272. In Cinebench R15 multi-core, the Opteron scores 448 against the Core i5's 354, a 26.6% advantage. Cinebench R20 multi-core repeats the pattern: 1870 versus 1479, a 26.4% lead. The single-core tests show the same 26.4% delta: 263 versus 208 in R20 single-core, and 628 versus 497 in R23 single-core. The R23 multi-core test also lands at 26.4%, with 4454 versus 3523.

The uniformity of these deltas is striking. Every test, whether single-core or multi-core, shows a 26.4% or 26.6% gap. This consistency suggests that the performance difference is not workload-dependent but rather a systemic property of the two processors under Cinebench. The Opteron's 16-core design appears to provide a fixed advantage across all tested scenarios, even where one might expect the Core i5's higher clocks to narrow the gap.

The Core i5-2500K does have additional benchmark records not shared with the Opteron. In Geekbench, the Core i5 scores 2434 multi-core and 805 single-core. These scores are not part of the head-to-head comparison, but they contribute to the Core i5's average benchmark score of 1329, which is higher than the Opteron's 1288. This average score places the Core i5 in the 35th percentile of all CPUs, the same percentile as the Opteron 6272. The Core i5's nearest rivals are the Intel Core i5-4460S at 1330 (0.1% higher) and the Intel Core i5-760 at 1337 (0.6% higher). The Opteron's nearest rivals include the Intel Core i7-3630QM at 1289 (0.1% lower) and the Intel Core i5-3570K at 1293 (0.4% lower).

The data indicates that while the Opteron wins every shared benchmark, the Core i5's overall average is slightly higher due to its Geekbench results. This creates a nuanced picture: the Opteron dominates Cinebench, but the Core i5 performs better in other workloads not captured in the head-to-head table.

Architecture Differences

The architectural divide is fundamental. The Opteron 6272 uses AMD's Bulldozer architecture, codenamed Interlagos, built on a 32 nm process at GlobalFoundries. The Core i5-2500K uses Intel's Sandy Bridge architecture, also on a 32 nm process but fabricated at Intel. The Opteron's dual-die design spans 2x 315 mm² with 2,400 million transistors, while the Core i5 uses a single 216 mm² die with 1,160 million transistors.

The Opteron's cache hierarchy reflects its server orientation: 768 KB of L1, 2 MB of L2 per module, and 8 MB of L3 per die. This per-module and per-die organization is designed for multi-threaded throughput across 16 cores. The Core i5's cache is per-core for L1 (64 KB) and L2 (256 KB), with a shared 6 MB L3, a configuration suited to desktop workloads where fewer threads run concurrently.

Memory architecture reinforces the server-versus-desktop split. The Opteron's quad-channel memory bus delivers 51.2 GB/s, double the Core i5's dual-channel 25.6 GB/s. ECC support on the Opteron allows error correction for mission-critical data integrity, while the Core i5 lacks this feature. The Opteron's socket is G34, designed for multi-socket servers, whereas the Core i5 uses Socket 1155 for single-socket desktops.

The Core i5-2500K includes an unlocked multiplier, enabling easy overclocking, and integrated Intel HD 3000 graphics. The Opteron 6272 has neither feature. The Opteron's PCIe Gen 2 support is not detailed with lane counts, while the Core i5 specifies 16 lanes on the CPU. The Opteron's market segment is explicitly Server/Workstation, while the Core i5 is a Desktop part.

The release dates differ by roughly ten months: the Core i5 launched in January 2011, the Opteron in November 2011. Launch MSRP values are available in the database: $523 for the Opteron 6272 and $216 for the Core i5-2500K. Both parts are end-of-life. The Opteron's part number is OS6272WKTGGGU, and the Core i5's is SR008. The Opteron's generation is listed as Opteron (Interlagos), while the Core i5's is Core i5 (Sandy Bridge). These architectural differences explain the benchmark outcomes: the Opteron's sheer core count and memory bandwidth overwhelm the Core i5 in Cinebench, while the Core i5's higher clocks, unlocked multiplier, and integrated graphics serve desktop users who prioritize single-thread responsiveness and flexibility.