AMD Opteron 6276 vs Intel Core i7-8665U Comparison

Where Each One Wins

The recorded benchmark data delivers an unusually clean split: the AMD Opteron 6276 wins every single one of the six head-to-head comparisons against the Intel Core i7-8665U. There is no test in the database where the Intel part manages to pull ahead, which makes the use-case distinction less about raw performance and more about the context each processor was built for.

The Opteron 6276 is a 16-core, 16-thread server and workstation processor from the Opteron 6000 series. Its wins in all three Cinebench multicore tests confirm that heavily threaded workloads are its natural territory. The Cinebench R15 multicore result shows a 3% advantage, the R20 multicore result shows a 3.1% advantage, and the R23 multicore result also shows a 3.1% advantage. These are consistent, if modest, margins. The single-core tests tell the same story: the Opteron leads by 2.7% in R15 single-core, 3.2% in R20 single-core, and 3.1% in R23 single-core. So even in workloads where the Intel chip's higher boost clock might be expected to help, the data does not show that.

The Core i7-8665U, by contrast, is a 4-core, 8-thread mobile processor built for thin-and-light laptops. Its 15 W TDP, compared to the Opteron's 115 W TDP, indicates that it is designed for environments where power draw and heat are tightly constrained. The database shows it losing every benchmark, but the margins are narrow, between 2.7% and 3.2%. For a chip with one quarter of the physical cores and a fraction of the power envelope, that is a notable result. It means the Intel part is competitive in short-duration productivity bursts, but it never surpasses the Opteron in any recorded test.

The percentile data reinforces this picture. The Opteron 6276 sits at the 39th percentile among all CPUs in the database, while the Core i7-8665U sits at the 38th percentile. For the Opteron, the nearest rivals by average benchmark score are the Intel Core i3-1115G4E at 1559 (a 0.1% difference), the AMD Ryzen 3 1300X at 1562 (minus 0.1%), the AMD FX-8350 at 1557 (0.2%), and the Intel Xeon E3-1268L v5 at 1557 (0.2%). For the Core i7-8665U, the nearest rivals are the Intel Pentium Gold G7400E at 1524 (minus 0.7%), the Intel Core i5-4670S at 1526 (minus 0.9%), the Intel Core i5-7440HQ at 1527 (minus 0.9%), and the Intel Core i3-8100T at 1500 (0.9%). Neither chip is a performance outlier within its own peer group; they are both mid-pack processors whose average scores land within a few points of similar-era parts.

Architecture Differences

The architecture gap between these two processors is substantial. The Opteron 6276 uses AMD's Bulldozer architecture, specifically the Interlagos codename, built on a 32 nm process at GlobalFoundries. It is a server-class design with 16 cores and 16 threads, meaning no simultaneous multithreading: each core handles one thread. The Core i7-8665U uses Intel's Whiskey Lake architecture, specifically the Whiskey Lake-U codename, built on a 14 nm process at Intel. It has 4 cores and 8 threads, so it does use hyper-threading to double the thread count.

The cache layouts differ in structure and philosophy. The Opteron has 768 KB of L1 cache, 2 MB of L2 cache per module, and 8 MB of L3 cache per die. The Core i7-8665U has 64 KB of L1 cache per core, 256 KB of L2 cache per core, and 8 MB of shared L3 cache. The Opteron's L3 is split per die rather than shared across the whole package, reflecting its multi-die server design. The Intel chip's L3 is shared across all four cores, which is typical for a mobile part.

Memory support is another clear differentiator. The Opteron supports DDR3 over a quad-channel memory bus with a peak bandwidth of 51.2 GB/s and includes ECC memory support. The Core i7-8665U supports both DDR3 and DDR4 over a dual-channel memory bus with a peak bandwidth of 38.4 GB/s and does not support ECC. The Opteron's higher memory bandwidth and ECC capability align with its server and workstation positioning, while the Intel part's dual-channel setup is sufficient for a mobile platform.

The PCIe generations also differ. The Opteron uses PCIe Gen 2, while the Core i7-8665U uses PCIe Gen 3 with 16 lanes on the CPU. The socket situation is entirely different as well: the Opteron uses AMD Socket G34, a large server socket, while the Intel part uses Intel BGA 1528, a soldered mobile package. The Intel chip also includes integrated graphics in the form of UHD Graphics 620, whereas the Opteron has no integrated graphics at all. The transistor count and die size for the Opteron are recorded as 2,400 million transistors across 2x 315 mm²; no such figures are recorded for the Intel part.

The release dates are roughly seven years apart. The Opteron 6276 launched on 2011-11-13, while the Core i7-8665U launched on 2018-09-30. Both are end-of-life products, and neither has an unlocked multiplier.

Head-to-Head Benchmarks

The six head-to-head benchmark entries all show the Opteron 6276 as the winner, with margins that cluster tightly around 3%. The largest advantage is in Cinebench R20 single-core, where the Opteron scores 319 against the Intel part's 309, a 3.2% delta. The smallest is in Cinebench R15 single-core, where the Opteron scores 76 against 74, a 2.7% delta. Every other test lands at either 3% or 3.1%.

In Cinebench R15 multicore, the Opteron scores 543 and the Core i7-8665U scores 527, giving the AMD part a 3% lead. In Cinebench R20 multicore, the Opteron scores 2265 and the Intel part scores 2197, a 3.1% lead. In Cinebench R23 multicore, the Opteron scores 5395 and the Intel part scores 5232, again a 3.1% lead. The single-core results follow the same pattern: R15 has the Opteron at 76 and the Intel part at 74, R20 has 319 versus 309, and R23 has 761 versus 738.

What is remarkable here is not the size of the wins, but their consistency. The Opteron leads by roughly the same percentage in both single-core and multicore tests, across three different generations of the Cinebench benchmark. This suggests that the performance gap between the two parts is not workload-dependent in the way one might expect from a 16-core server chip versus a 4-core mobile chip. The Intel part's higher boost clock, which is recorded as 4.80 GHz against the Opteron's 3.20 GHz, does not translate into a single-core victory in any recorded test. The Opteron's base clock of 2.30 GHz is also lower than the Intel part's base clock of 1900.00 MHz, yet the AMD chip still wins.

The average benchmark scores reflect the same ordering: the Opteron has an average score of 1560, while the Core i7-8665U has an average score of 1513. That is a difference of 47 points, or roughly 3.1%, which matches the head-to-head deltas almost exactly. The consistency between the average score and the individual head-to-head results strengthens the conclusion that the Opteron is the faster processor in this database across all recorded Cinebench workloads.

The Verdict

The data points in one direction. The AMD Opteron 6276 wins all six head-to-head benchmarks against the Intel Core i7-8665U, with margins between 2.7% and 3.2%. It also holds a higher average benchmark score, 1560 versus 1513, and a marginally higher percentile ranking, 39th versus 38th. For anyone choosing purely on recorded Cinebench performance, the Opteron is the clear pick.

However, the verdict is not simply about who wins. The Opteron is a server and workstation processor with a 115 W TDP, a quad-channel DDR3 memory bus, ECC support, and no integrated graphics. It requires an AMD Socket G34 platform and was designed for rack-mounted or tower server environments where power and cooling are not limiting factors. The Core i7-8665U is a mobile processor with a 15 W TDP, dual-channel memory support, and integrated UHD Graphics 620. It is built for laptops and compact systems where power efficiency and reduced heat output are priorities.

The recorded data shows that the Opteron is faster in every single Cinebench test, but it does not show that the Opteron is the better fit for every use case. On a server or workstation workload with sustained multicore demand, the Opteron's 16 cores and higher memory bandwidth give it the edge. In a mobile context, where the Intel part's 15 W power draw and integrated graphics make it practical in ways the Opteron cannot match, the Core i7-8665U is the only viable option of the two. The benchmark scores are one input; the platform requirements are another. The database supports the Opteron as the faster chip, while the Intel part remains the appropriate choice for mobile systems.

FAQ

Q: Which processor wins more benchmarks in the database?

A: The AMD Opteron 6276 wins all 6 head-to-head benchmark entries against the Intel Core i7-8665U. The Intel part records 0 wins.

Q: How large is the performance gap between the two processors?

A: The Opteron leads by between 2.7% and 3.2% across the six recorded tests. The largest margin is 3.2% in Cinebench R20 single-core, and the smallest is 2.7% in Cinebench R15 single-core.

Q: What are the core and thread counts for each processor?

A: The AMD Opteron 6276 has 16 cores and 16 threads. The Intel Core i7-8665U has 4 cores and 8 threads.

Q: Does the Core i7-8665U have integrated graphics?

A: Yes, the Intel Core i7-8665U includes UHD Graphics 620. The AMD Opteron 6276 has no integrated graphics.

Q: Which processor supports ECC memory?

A: The AMD Opteron 6276 supports ECC memory. The Intel Core i7-8665U does not support ECC.

Q: How do the two processors compare in average benchmark score?

A: The AMD Opteron 6276 has an average benchmark score of 1560, while the Intel Core i7-8665U has an average score of 1513. The Opteron also sits at the 39th percentile versus the Intel part's 38th percentile.

Specification Differences

The two processors differ in nearly every recorded specification category. The Opteron 6276 has 16 cores and 16 threads, while the Core i7-8665U has 4 cores and 8 threads. The Opteron's base clock is 2.30 GHz and its boost clock is 3.20 GHz; the Intel part's base clock is 1900.00 MHz and its boost clock is 4.80 GHz. The Opteron has a TDP of 115 W, the Intel part has a TDP of 15 W. The Opteron uses AMD Socket G34, the Intel part uses Intel BGA 1528. The Opteron is built on a 32 nm process at GlobalFoundries with 2,400 million transistors and a die size of 2x 315 mm²; the Intel part is built on a 14 nm process at Intel, with no transistor or die size figures recorded.

The cache configurations differ as well. The Opteron has 768 KB of L1, 2 MB of L2 per module, and 8 MB of L3 per die. The Intel part has 64 KB of L1 per core, 256 KB of L2 per core, and 8 MB of shared L3. The Opteron supports DDR3 memory over a quad-channel bus with 51.2 GB/s bandwidth and ECC support. The Intel part supports DDR3 and DDR4 over a dual-channel bus with 38.4 GB/s bandwidth and no ECC support. The Opteron uses PCIe Gen 2; the Intel part uses PCIe Gen 3 with 16 lanes on the CPU. The Opteron has no integrated graphics; the Intel part has UHD Graphics 620. The market segments differ, with the Opteron listed as Server/Workstation and the Intel part as Mobile. Both are end-of-life products, and neither has an unlocked multiplier.