Intel Core i5-6600 vs Intel Core i7-980X Comparison

The Intel Core i7-980X and Intel Core i5-6600 represent two very different eras of desktop computing, yet their aggregate benchmark scores place them in a statistical dead heat. The i7-980X averages 1746 points, while the i5-6600 sits at 1744 points, a negligible 0.1% difference. Both processors occupy the 41st percentile of all CPUs tested, indicating that despite their generational gap, they deliver comparable overall performance. The data reveals a fascinating split: the older six-core Gulftown part dominates Cinebench rendering workloads, while the newer Skylake chip excels in Geekbench, particularly in single-threaded tests. This head-to-head analysis dissects where each processor wins and why, based strictly on benchmark results.

Head-to-Head Benchmarks

The Cinebench suite paints a consistent picture of victory for the Intel Core i7-980X. Across all three versions of the benchmark (R15, R20, and R23), the i7-980X wins both multi-core and single-core tests with a remarkably uniform margin. In Cinebench R15 multi-core, the i7-980X scores 584 against the i5-6600's 520, a 12.3% advantage. The same delta appears in R15 single-core (82 vs 73, 12.3%) and R20 multi-core (2434 vs 2167, 12.3%). The i7-980X extends its lead slightly in R20 single-core with 343 points versus 305, a 12.5% margin, and in R23 single-core, where it posts 818 against the i5-6600's 728, a 12.4% edge. In Cinebench R23 multi-core, the i7-980X again wins by 12.3%, scoring 5797 to the i5-6600's 5161.

These results are striking because they show the i7-980X winning not just in multi-threaded workloads, where its 6 cores and 12 threads should provide an advantage, but also in single-core Cinebench tests. The 3.33 GHz base clock of the i7-980X, while lower than the i5-6600's 3.30 GHz base, is paired with a boost clock of 3.60 GHz. However, the i5-6600 boosts to 3.90 GHz. Despite this frequency disadvantage, the i7-980X still edges out the i5-6600 in Cinebench single-core, suggesting that the older Westmere architecture handles this specific workload more efficiently than Skylake.

The Geekbench results tell the opposite story, and the margins are far larger. In Geekbench multi-core, the i5-6600 scores 3755 against the i7-980X's 3247, a 13.5% victory. The single-core Geekbench test is a blowout: the i5-6600 posts 1239, while the i7-980X manages only 659. That is a 46.8% difference, the largest delta in the entire comparison. The i5-6600's 3.90 GHz boost clock clearly pays dividends here, as does its newer Skylake architecture, which delivers substantially better instructions-per-clock in this benchmark. The i7-980X's older design, despite its higher core count, cannot overcome the per-core efficiency deficit in Geekbench's single-threaded workload.

The final tally shows the i7-980X winning 6 of 8 benchmarks, with the i5-6600 taking 2. However, the magnitude of the i5-6600's Geekbench wins, especially the near-47% single-core margin, demonstrates that the newer processor holds a significant advantage in certain types of workloads. The i7-980X's wins are uniformly around 12-13%, while the i5-6600's multi-core win is 13.5% and its single-core win is 46.8%. This asymmetry means the choice between these CPUs depends heavily on the intended application.

The Verdict

The benchmark data presents a clear, if nuanced, verdict. For users running Cinebench-style rendering workloads—which are representative of many 3D rendering and video encoding tasks—the Intel Core i7-980X is the superior choice. It wins every Cinebench test by a consistent 12.3% to 12.5% margin, including single-core variants, and its 6 cores and 12 threads provide a tangible advantage in multi-threaded rendering. The i7-980X's 12 MB of shared L3 cache, double the i5-6600's 6 MB, likely contributes to its sustained performance in these workloads.

Conversely, the Intel Core i5-6600 is the better option for Geekbench-style workloads, which often reflect general productivity and everyday computing tasks. Its 46.8% lead in single-core Geekbench and 13.5% lead in multi-core Geekbench indicate that it offers snappier responsiveness in single-threaded applications and better performance in memory-latency-sensitive tasks. The i5-6600's dual-channel memory bus, while narrower than the i7-980X's triple-channel setup, benefits from support for DDR4 memory, which provides higher bandwidth per channel. The i5-6600 also integrates UHD Graphics 530, eliminating the need for a discrete GPU in basic systems, while the i7-980X has no integrated graphics.

From a platform perspective, the i5-6600 runs on Intel Socket 1151 with a 35W TDP, making it far more power-efficient than the i7-980X's 130W TDP. The i7-980X requires Intel Socket 1366 and triple-channel DDR3 memory, while the i5-6600 supports both DDR3 and DDR4 on a dual-channel bus, offering more flexibility in memory selection. The i5-6600's PCIe Gen 3 support with 16 lanes also provides modern connectivity, whereas the i7-980X is limited to PCIe Gen 2. For a new build, the i5-6600 is the more practical choice; for a legacy rendering workstation, the i7-980X delivers superior Cinebench performance.

Architecture Differences

The Intel Core i7-980X is built on the Westmere architecture, codenamed Gulftown, using a 32 nm process node. It packs 1,170 million transistors into a 239 mm² die. This is a six-core, twelve-thread processor with a 3.33 GHz base clock and 3.60 GHz boost clock. The i7-980X features a triple-channel memory bus supporting DDR3, and its cache hierarchy includes 64 KB of L1 per core and 256 KB of L2 per core, with a shared 12 MB L3 cache. It uses PCIe Gen 2 and has an unlocked multiplier, making it suitable for overclocking.

The Intel Core i5-6600 is a Skylake architecture part, also codenamed Skylake, manufactured on a newer 14 nm process. It has a smaller die size of 177 mm², and while its transistor count is not listed, the smaller node typically allows for greater density. The i5-6600 is a quad-core, four-thread processor with a 3.30 GHz base clock and a 3.90 GHz boost clock. It supports dual-channel DDR3 or DDR4 memory, with a specified memory bandwidth of 34.1 GB/s. Its cache is 64 KB L1 per core and 256 KB L2 per core, with a smaller 6 MB shared L3 cache. The i5-6600 uses PCIe Gen 3 with 16 lanes and includes integrated UHD Graphics 530. Its multiplier is locked, preventing traditional overclocking.

The most fundamental architectural difference is the core and thread count: the i7-980X offers 6 cores and 12 threads, while the i5-6600 offers 4 cores and 4 threads. The i7-980X's Hyper-Threading technology doubles its thread count, which is a major factor in its Cinebench multi-core wins. The i5-6600 lacks Hyper-Threading, relying instead on higher clock speeds and a newer microarchitecture. The process node difference, 32 nm versus 14 nm, also explains the i5-6600's significantly lower TDP of 35W versus the i7-980X's 130W.

Specification Differences

The two processors differ across several key specifications. The i7-980X has 6 cores and 12 threads, while the i5-6600 has 4 cores and 4 threads. Base clocks are nearly identical at 3.33 GHz and 3.30 GHz, respectively, but the boost clocks diverge: 3.60 GHz for the i7-980X and 3.90 GHz for the i5-6600. The TDP is a major difference, with the i7-980X rated at 130W and the i5-6600 at just 35W. The sockets are incompatible: the i7-980X uses Intel Socket 1366, while the i5-6600 uses Intel Socket 1151.

Memory support differs significantly. The i7-980X supports only DDR3 with a triple-channel memory bus, while the i5-6600 supports both DDR3 and DDR4 with a dual-channel bus. The i5-6600 also has a listed memory bandwidth of 34.1 GB/s, which the i7-980X lacks. PCIe support is generational: the i7-980X has PCIe Gen 2, while the i5-6600 has PCIe Gen 3 with 16 lanes. The i7-980X has no integrated graphics, whereas the i5-6600 includes UHD Graphics 530. The i7-980X has an unlocked multiplier; the i5-6600 does not. Finally, the i7-980X has 12 MB of shared L3 cache versus 6 MB on the i5-6600.

FAQ

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

A: The Intel Core i7-980X is faster, scoring 5797 against the i5-6600's 5161, a 12.3% advantage.

Q: How much better is the i5-6600 in Geekbench single-core?

A: The i5-6600 scores 1239 versus the i7-980X's 659, representing a 46.8% lead.

Q: Do both processors support DDR4 memory?

A: No. The i7-980X supports only DDR3 with a triple-channel bus. The i5-6600 supports both DDR3 and DDR4 with a dual-channel bus.

Q: What is the TDP of each processor?

A: The i7-980X has a TDP of 130W, while the i5-6600 has a TDP of 35W.

Q: Which CPU has integrated graphics?

A: Only the i5-6600 has integrated graphics, featuring UHD Graphics 530. The i7-980X has no integrated graphics.

Q: How do their aggregate benchmark scores compare?

A: The i7-980X has an average benchmark score of 1746, and the i5-6600 has an average of 1744, a difference of just 0.1% in favor of the i7-980X.