Intel Core i7-5820K

The Intel Core i7-5820K is a six-core, twelve-thread desktop processor built on the Haswell-E architecture, released in late August 2014. It operates with a base clock of 3.30 GHz and a boost clock of 3.60 GHz, featuring an unlocked multiplier for overclocking. This end-of-life chip uses the Intel Socket 2011-3 platform, supports quad-channel DDR4 memory with a bandwidth of 68.3 GB/s, and provides 28 PCIe Gen 3 lanes from the CPU. Its average benchmark score of 2640 places it at the 52nd percentile among all CPUs, indicating a mid-pack position in the broader performance landscape, with results that are closely clustered around several contemporaries.

Benchmark Performance

The benchmark data shows a processor that is consistent across different testing generations, with its multi-core scores scaling predictably from Cinebench R15 to R23. In Cinebench R15, the i7-5820K scores 841 points in the multi-core test and 118 in the single-core test. Moving to Cinebench R20, the multi-core score jumps to 3505, while single-core reaches 494. The most recent Cinebench R23 results show 8347 points multi-core and 1178 single-core. These figures indicate a strong multi-threaded capability that remains competitive for its era, though the single-core scores reveal its age relative to newer architectures.

The Geekbench results paint a similar picture: a multi-core score of 5464 and a single-core score of 1174. The gap between multi-core and single-core performance is substantial, with the multi-core score being roughly 4.7 times higher in Geekbench, reflecting the benefit of twelve threads across six physical cores. This ratio is typical for a Haswell-E part, where the architecture prioritizes parallel throughput over per-core speed.

When compared to its nearest rivals by average score, the i7-5820K sits in a remarkably tight cluster. It is 0.1% ahead of the Intel Core i7-7740X, which posts an average score of 2639. The difference is negligible, effectively a statistical tie. Against the Intel Core i7-8700T, the i7-5820K leads by 0.2%, with the rival scoring 2636. Conversely, it trails the Intel Xeon E-2274G by 0.2% (that chip scores 2645) and the AMD Ryzen 5 4500U by 0.3% (score of 2647). These deltas are all within a fraction of a percent, meaning the i7-5820K delivers performance nearly identical to four different processors from various generations and market segments.

How It Compares

Intel Core i7-7740X: The i7-7740X is the closest competitor, with an average score of 2639 against the i7-5820K’s 2640. The 0.1% advantage for the i7-5820K is imperceptible in real-world use. Both are unlocked desktop parts, but the i7-5820K offers more cores and threads (6/12 vs. the 7740X’s 4/8), which suggests the i7-5820K would handle heavily threaded workloads better, despite the equal average scores. The benchmark parity here is a testament to the i7-5820K’s strong multi-core showing offsetting its weaker single-core speed.

Intel Core i7-8700T: The i7-8700T, a low-power variant, scores 2636 on average, putting it 0.2% behind the i7-5820K. This is notable because the 8700T is a newer, more power-efficient design, yet the older Haswell-E chip still edges it out in overall average performance. The i7-5820K’s six cores and twelve threads match the 8700T’s core count, but the 5820K’s higher TDP of 140W allows for sustained boost clocks that close the gap with newer, more efficient silicon.

Intel Xeon E-2274G: The Xeon E-2274G scores 2645, which is 0.2% higher than the i7-5820K. This server-class chip, despite having only four cores and eight threads, manages to outperform the six-core i7-5820K in average benchmarks. The result highlights how architectural improvements in newer generations can overcome a core count disadvantage. For single-threaded tasks, the Xeon likely pulls ahead significantly, while the i7-5820K would win in multi-threaded scenarios, but the averaged benchmark hides that nuance.

AMD Ryzen 5 4500U: The Ryzen 5 4500U, a mobile processor, achieves an average score of 2647, which is 0.3% higher than the i7-5820K. This is a striking comparison: a low-power laptop chip outperforms a desktop enthusiast part from 2014. The Ryzen’s newer Zen 2 architecture delivers better instructions per clock, allowing it to match the i7-5820K’s multi-threaded output despite likely having fewer active threads in some tests. For the i7-5820K, this underscores that its raw core count no longer guarantees an advantage over modern designs.

Power and Thermals

The i7-5820K carries a TDP of 140W, which places it in the high-power desktop category. This is a substantial thermal load that requires a capable air cooler or a basic liquid cooling solution to manage effectively, especially under sustained all-core workloads. The 22nm process node from Intel, with 2,600 million transistors on a 356 mm² die, contributes to this power draw. The large die size and high transistor count mean heat density is a consideration.

For builders, this TDP class implies a need for robust cooling infrastructure. A stock cooler is not provided with this end-of-life part, so an aftermarket solution is mandatory. The motherboard must also support the 140W TDP with a proper VRM design to avoid throttling. Given the quad-channel DDR4 memory support and the Socket 2011-3 platform, this chip was intended for high-end desktops where cooling and power delivery are assumed to be adequate. Users coming from lower-TDP platforms should budget for a larger heatsink or radiator to keep temperatures in check during extended rendering or compilation sessions.

FAQ

Q: What is the core and thread count of the Intel Core i7-5820K?

A: It has 6 cores and 12 threads, which allows it to process 12 concurrent tasks, a key factor in its multi-core benchmark scores.

Q: What memory type does this processor support?

A: It supports DDR4 memory with a quad-channel bus, providing a memory bandwidth of 68.3 GB/s. This is a distinguishing feature of the Socket 2011-3 platform.

Q: Is the multiplier unlocked for overclocking?

A: Yes, the multiplier is unlocked, meaning users can adjust the clock speeds beyond the stock 3.30 GHz base and 3.60 GHz boost if their cooling and motherboard allow.

Q: How does the i7-5820K perform in Cinebench R23?

A: It scores 8347 points in the multi-core test and 1178 points in the single-core test. The multi-core score is over seven times higher, showing a strong scaling with thread count.

Q: What is the average benchmark score and percentile ranking?

A: The average benchmark score is 2640, and it ranks in the 52nd percentile of all CPUs. This places it squarely in the middle of the performance distribution.

Q: Does it have integrated graphics?

A: No, the Fact Pack lists no integrated graphics for this processor, meaning a discrete GPU is required for any display output.

Single-Thread vs Multi-Thread Behavior

The i7-5820K exhibits a pronounced split between single-thread and multi-thread performance. In Cinebench R23, the single-core score of 1178 is modest by modern standards, while the multi-core score of 8347 is relatively robust. The ratio between these scores, roughly 7.1 to 1, indicates that the processor scales exceptionally well when all twelve threads are engaged. This is a hallmark of the Haswell-E design, which focuses on providing many cores at a moderate clock speed rather than chasing high per-core frequency.

In Geekbench, the single-core score of 1174 versus a multi-core score of 5464 shows a ratio of about 4.7 to 1. The difference in ratios between Cinebench and Geekbench reflects the varying workloads each test uses; Cinebench R23 is highly parallelizable, while Geekbench includes a mix of tasks that are not all thread-bound. For real-world applications, this means the i7-5820K will excel in video rendering, 3D modeling, and software compilation, where all cores are utilized. Conversely, tasks like web browsing, spreadsheet work, or older games that rely on one or two threads will see performance closer to the single-core scores, which lag behind modern CPUs.

The 140W TDP and 3.60 GHz boost clock suggest that thermal headroom is available for overclocking, which could mitigate the single-thread gap. However, even with an aggressive overclock, the architectural limits of Haswell prevent it from matching the per-core speed of newer designs. Users should expect a smooth experience in multi-threaded production work but may notice slower response in lightly threaded applications when compared to more recent processors.

Who Should Consider It

Gamers building a system around the i7-5820K should focus on its multi-threaded strengths and be aware of its single-thread limits. The Cinebench R23 single-core score of 1178 indicates that it will not lead the pack in games that are sensitive to per-core speed, especially at high refresh rates. However, for games that scale well across multiple cores, the six cores and twelve threads provide a solid foundation. The 28 PCIe Gen 3 lanes from the CPU allow for multi-GPU configurations, which is a niche advantage for those running multiple graphics cards.

Content creators and professionals handling video editing, 3D rendering, or data processing will find the i7-5820K more compelling. The Cinebench R23 multi-core score of 8347 and Geekbench multi-core score of 5464 show that it can handle substantial parallel workloads. The quad-channel DDR4 memory support, with 68.3 GB/s bandwidth, further benefits memory-intensive tasks like large dataset manipulation or high-resolution video scrubbing. For these workloads, the 0.2-0.3% differences against its nearest rivals are irrelevant; the consistent multi-core throughput is what matters.

Office and general productivity users should look elsewhere, as the single-core scores are not competitive with modern chips, and the 140W TDP is excessive for mundane tasks. The i7-5820K is a specialized tool best suited for users who know they will consistently push all twelve threads. Its 52nd percentile ranking reflects this: it is neither a top-tier performer nor a weak one, but rather a capable processor for specific high-throughput scenarios. Those who require maximum single-thread performance or energy efficiency should consider newer options, while those with heavily threaded workloads on a budget can still extract value from this end-of-life part.