AMD Opteron 6276 vs Intel Core i5-6600T Comparison

The data presents an unusual head-to-head: a 4-core, 35W desktop part from 2015 against a 16-core, 115W server processor from 2011. The benchmark results are remarkably one-sided, with the older AMD Opteron 6276 winning every single test in the comparison suite. The average benchmark scores are nearly identical, with the Intel Core i5-6600T at 1563 and the AMD Opteron 6276 at 1560, yet the individual Cinebench runs tell a different story. This suggests that while their overall synthetic averages align, their performance characteristics diverge significantly depending on the workload.

Head-to-Head Benchmarks

The AMD Opteron 6276 dominates the Cinebench suite across the board, but the margins are consistently tight. In Cinebench R15 multi-core, the Opteron scores 543 against the Core i5-6600T’s 478, a 12% advantage. The single-core test in R15 shows a similar pattern: 76 for AMD versus 67 for Intel, an 11.8% lead for the Opteron. This is surprising, as single-core performance is typically a strength of Intel’s Skylake architecture, yet the data shows the older Bulldozer-based chip maintaining its edge.

Moving to Cinebench R20, the results mirror the R15 findings. The Opteron’s multi-core score of 2265 eclipses Intel’s 1992 by 12.1%, while the single-core score of 319 versus 280 represents a 12.2% advantage. The trend continues into Cinebench R23, where the Opteron scores 5395 multi-core and 761 single-core, compared to the i5-6600T’s 4745 and 669. The deltas remain remarkably stable at roughly -12% across all six tests, suggesting a consistent performance gap rather than workload-specific variations.

What is striking is that the Core i5-6600T fails to win a single benchmark in this head-to-head dataset. Even in Geekbench, where the i5-6600T has scores of 3104 multi-core and 1172 single-core, there is no corresponding Opteron score listed for comparison. The absence of Geekbench results for the Opteron means we cannot assess its performance there, but within the Cinebench family, the Opteron’s victory is absolute. The 16-core count likely provides the multi-threaded advantage, but the single-core wins suggest that AMD’s higher boost clock of 3.20 GHz, compared to Intel’s 3.50 GHz, does not translate into an Intel advantage here.

Where Each One Wins

Based strictly on the head-to-head data, the AMD Opteron 6276 wins everywhere. It takes all six Cinebench tests, covering both multi-core and single-core scenarios across three different Cinebench versions. This means that for any workload that relies on Cinebench-style rendering or compute tasks, the Opteron is the clear choice. The consistency of the ~12% margin indicates this is not a fluke or a test-specific anomaly but a fundamental performance characteristic.

The Intel Core i5-6600T, however, has strengths that are not captured in the head-to-head suite. Its Geekbench scores of 3104 multi-core and 1172 single-core are standalone figures, and while we lack Opteron comparisons, these numbers place the i5 in a competitive position. Furthermore, the i5’s 35W TDP versus the Opteron’s 115W TDP suggests a massive efficiency advantage. In power-constrained environments or compact systems, the i5-6600T would be the only viable option, as the Opteron’s power draw is over three times higher. The i5 also features integrated graphics, which the Opteron lacks entirely, making the Intel part self-sufficient for basic display output.

The Opteron’s win is not just about raw scores. Its 16 threads, compared to the i5’s 4 threads, allow it to handle heavily parallel workloads with greater ease. The data implies that for server-style tasks, database processing, or multi-threaded rendering, the Opteron’s architecture offers more headroom. Conversely, the i5’s modern Skylake architecture and 14nm process node versus the Opteron’s 32nm process suggest better instruction-level efficiency and lower latency per core, even if the benchmark scores do not reflect this advantage.

The Verdict

The data is unambiguous: the AMD Opteron 6276 outperforms the Intel Core i5-6600T in every measured Cinebench test. If the primary criterion is raw computational throughput, the Opteron is the superior processor, delivering a consistent 12% lead in both multi-core and single-core workloads. This is remarkable given that the Opteron is four years older, released in 2011 versus the i5’s 2015 launch. The Opteron’s 16 cores and 16 threads provide a parallel processing advantage that the i5’s 4 cores and 4 threads cannot match, even with Intel’s superior clock speeds and architectural efficiency.

However, the verdict is not a simple recommendation for the Opteron. The i5-6600T’s 35W TDP makes it suitable for low-power, small-form-factor builds, where the Opteron’s 115W TDP would be prohibitive. The i5 also supports DDR3 and DDR4 memory, while the Opteron is limited to DDR3, offering more flexibility in system builds. The i5’s integrated graphics and PCIe Gen 3 support (versus the Opteron’s Gen 2) make it a more modern and versatile platform. For a user building a quiet, efficient desktop, the i5 is the logical choice, despite its benchmark deficit. For a user with a server motherboard that supports Socket G34 and who prioritizes multi-threaded throughput, the Opteron’s performance edge is compelling.

FAQ

Q: Which processor wins in multi-core performance?

A: The AMD Opteron 6276 wins in all multi-core tests. In Cinebench R15, it scores 543 versus the Intel Core i5-6600T’s 478, a 12% advantage. In R20, the scores are 2265 versus 1992, and in R23, they are 5395 versus 4745.

Q: Does the Intel Core i5-6600T win any single-core tests?

A: No. The Opteron 6276 also wins all single-core tests, with scores of 76 versus 67 in R15, 319 versus 280 in R20, and 761 versus 669 in R23. Each victory is approximately 12%.

Q: What are the average benchmark scores for these two CPUs?

A: The Intel Core i5-6600T has an average benchmark score of 1563, while the AMD Opteron 6276 has an average of 1560. The difference is only 0.2%, with the i5 slightly ahead in this aggregate metric.

Q: How do these processors compare in terms of power consumption?

A: The Intel Core i5-6600T has a TDP of 35W, while the AMD Opteron 6276 has a TDP of 115W. This makes the i5 significantly more power-efficient, over three times lower in thermal design power.

Q: What memory types does each processor support?

A: The Intel Core i5-6600T supports both DDR3 and DDR4 memory, while the AMD Opteron 6276 supports only DDR3. The i5 uses a dual-channel memory bus, whereas the Opteron uses a quad-channel bus.

Q: Which processor has integrated graphics?

A: The Intel Core i5-6600T includes UHD Graphics 530. The AMD Opteron 6276 does not have any integrated graphics, requiring a discrete GPU for display output.

Architecture Differences

The architectural gap between these two processors is vast, reflecting their different design goals and eras. The Intel Core i5-6600T is built on the Skylake architecture using a 14nm process node, manufactured by Intel. Its die size is 177 mm², and it features 4 cores and 4 threads. The cache hierarchy is per-core for L1 and L2, with 64 KB L1 and 256 KB L2 per core, plus a shared 6 MB L3 cache. This is a modern, efficient design focused on low power consumption and high single-thread performance.

The AMD Opteron 6276 uses the Bulldozer architecture, codenamed Interlagos, on a 32nm process node from GlobalFoundries. It is a massive chip with 2,400 million transistors and a die size of 2x 315 mm², meaning it uses two dies. It has 16 cores and 16 threads, organized in modules. Its cache is structured differently: 768 KB of L1, 2 MB of L2 per module, and 8 MB of L3 per die. The Bulldozer design was AMD’s attempt to scale core counts for server workloads, but it sacrificed single-thread efficiency. The Opteron supports ECC memory, while the i5 does not, and the Opteron’s PCIe is Gen 2 versus the i5’s Gen 3. These differences explain why the Opteron can win in raw throughput despite being older and less efficient.

Specification Differences

The specification sheets diverge on nearly every major point. The Intel Core i5-6600T has 4 cores and 4 threads, while the AMD Opteron 6276 has 16 cores and 16 threads. The i5’s base clock is 2.70 GHz with a boost of 3.50 GHz, whereas the Opteron operates at 2.30 GHz base and 3.20 GHz boost. The TDP is a major differentiator: 35W for Intel versus 115W for AMD. The sockets are incompatible, with the i5 using Intel Socket 1151 and the Opteron using AMD Socket G34.

Memory support also differs: the i5 supports DDR3 and DDR4 on a dual-channel bus with 34.1 GB/s bandwidth, while the Opteron only supports DDR3 on a quad-channel bus with 51.2 GB/s bandwidth. The i5 has integrated graphics (UHD Graphics 530), while the Opteron has none. The i5 supports PCIe Gen 3 with 16 lanes (CPU only), while the Opteron uses PCIe Gen 2. The i5 does not support ECC memory, but the Opteron does. The process nodes are 14nm for Intel and 32nm for AMD, and the market segments are Desktop versus Server/Workstation. The launch MSRP for the i5 is $213, while the Opteron launched at $788. The i5’s part number is SR2L9, and the Opteron’s is OS6276WKTGGGU.