Intel Core i5-8600K vs Intel Core i7-6800K Comparison

The Intel Core i7-6800K and the Intel Core i5-8600K are both six-core desktop processors from Intel, but they target different platforms and eras. The i7-6800K, a Broadwell-E part with a launch MSRP of $434, and the i5-8600K, a Coffee Lake part with a launch MSRP of $257, deliver nearly identical overall average benchmark scores. The data shows the i7-6800K averages 2838 across all tests, while the i5-8600K averages 2807, a difference of roughly 1%. Both CPUs sit at the 51st percentile among all tested CPUs, placing them in the same performance tier despite their architectural differences.

Head-to-Head Benchmarks

The Cinebench suite heavily favors the i7-6800K. Across every Cinebench iteration and workload type, the older Broadwell-E chip maintains a consistent lead. In Cinebench R15 multicore, the i7-6800K scores 916 against the i5-8600K’s 867, a 5.7% advantage. The single-core test in R15 shows the same 5.7% delta, with scores of 129 and 122 respectively. This pattern holds in Cinebench R20, where the i7-6800K posts 3819 multicore and 538 single-core, versus 3616 and 510 for the i5-8600K; both deltas sit at 5.6% and 5.5%. The most recent Cinebench R23 results continue the trend: the i7-6800K scores 9093 multicore and 1283 single-core, while the i5-8600K trails at 8611 and 1215, each a 5.6% gap.

The i5-8600K takes its wins in the Geekbench suite, and it wins decisively there. In Geekbench single-core, the i5-8600K scores 1514 versus the i7-6800K’s 1237, a massive 18.3% margin. That is the largest performance gap recorded in any head-to-head test between these two processors. The multicore Geekbench result is closer but still favors the i5-8600K: 5997 versus 5688, a 5.2% lead. Interestingly, the Geekbench multicore result contradicts the Cinebench multicore results, where the i7-6800K consistently wins by roughly 5.6%. This discrepancy suggests the two workloads stress different aspects of the processors, with Cinebench rewarding the i7-6800K’s extra threads and Geekbench favoring the i5-8600K’s higher clock speeds.

Overall, the i7-6800K wins 6 of the 8 head-to-head benchmarks, but the i5-8600K’s Geekbench single-core victory is so large that it nearly balances the aggregate scores in that suite. The average benchmark score remains close because Cinebench and Geekbench are weighted equally in the database’s averaging, and the i5-8600K’s single-core dominance offsets its multicore deficit in Geekbench. The data reveals a clear split: the i7-6800K is the stronger Cinebench performer across the board, while the i5-8600K is the stronger Geekbench performer, particularly in single-threaded workloads.

Where Each One Wins

The i7-6800K wins exclusively in Cinebench tests, both multicore and single-core, across R15, R20, and R23. This consistency indicates that the processor’s architecture and 12 threads provide a measurable advantage in rendering and content-creation workloads that rely on sustained multi-threaded execution. The 5.5% to 5.7% advantage in every Cinebench test is uniform, suggesting the extra threads from Hyper-Threading are the primary driver, as the i7-6800K has 12 threads versus the i5-8600K’s 6. The single-core Cinebench wins are less expected, given the i5-8600K’s higher boost clock of 4.30 GHz versus 3.60 GHz, but the data shows the i7-6800K still edges ahead by 5.7% in R15 single-core.

The i5-8600K wins in Geekbench, with its single-core score being the standout. The 18.3% lead in Geekbench single-core is the single largest delta between the two CPUs in any test, indicating that the i5-8600K’s Coffee Lake architecture is significantly more efficient per clock in this specific workload. The i5-8600K also wins Geekbench multicore by 5.2%, despite having half the threads of the i7-6800K. This suggests that in Geekbench, raw clock speed and newer microarchitecture matter more than thread count. For users running Geekbench-style applications, the i5-8600K is the clear choice; for users running Cinebench-style rendering, the i7-6800K is superior.

The use-case split is therefore stark. The i7-6800K is the pick for Cinebench-heavy workloads, which typically include 3D rendering and animation. The i5-8600K is the pick for Geekbench-heavy workloads, which often include general productivity, web browsing, and single-threaded applications. The two CPUs are nearly identical in overall average score, so the decision hinges entirely on which benchmark suite better represents the target workload.

FAQ

Q: Which CPU has the higher average benchmark score?

A: The Intel Core i7-6800K has an average benchmark score of 2838, while the Intel Core i5-8600K has an average score of 2807. The difference is approximately 1% in favor of the i7-6800K.

Q: How large is the single-core performance gap in Geekbench?

A: The i5-8600K leads by 18.3% in Geekbench single-core, scoring 1514 versus the i7-6800K’s 1237. This is the largest delta in any head-to-head benchmark between the two.

Q: Does the i7-6800K win any single-core tests?

A: Yes, the i7-6800K wins all Cinebench single-core tests. In Cinebench R15, it scores 129 versus 122; in R20, 538 versus 510; and in R23, 1283 versus 1215. Each win is approximately 5.6% to 5.7%.

Q: What is the memory bandwidth difference?

A: The i7-6800K supports quad-channel memory with 76.8 GB/s of bandwidth, while the i5-8600K supports dual-channel memory with 42.7 GB/s of bandwidth. The i7-6800K offers nearly double the theoretical memory bandwidth.

Q: Do both CPUs have the same number of cores?

A: Yes, both have 6 physical cores. However, the i7-6800K has 12 threads, while the i5-8600K has 6 threads, meaning the i7-6800K supports simultaneous multi-threading and the i5-8600K does not.

Q: Which CPU has integrated graphics?

A: Only the i5-8600K includes integrated graphics, specifically UHD Graphics 630. The i7-6800K has no integrated graphics, requiring a discrete GPU for display output.

Specification Differences

The two processors differ in almost every core specification except core count. The i7-6800K has 6 cores and 12 threads, while the i5-8600K has 6 cores and 6 threads. Base clocks differ: the i7-6800K runs at 3.40 GHz, while the i5-8600K runs at 3.60 GHz. Boost clocks show a larger gap, with the i7-6800K boosting to 3.60 GHz and the i5-8600K boosting to 4.30 GHz. Thermal design power also diverges significantly: the i7-6800K has a 140W TDP, while the i5-8600K has a 95W TDP.

The sockets are incompatible. The i7-6800K uses Intel Socket 2011-3, while the i5-8600K uses Intel Socket 1151. Memory support differs in channel count: the i7-6800K supports quad-channel DDR4 with 76.8 GB/s bandwidth, while the i5-8600K supports dual-channel DDR4 with 42.7 GB/s bandwidth. PCIe lane counts also differ, with the i7-6800K offering 28 CPU lanes (Gen 3) versus the i5-8600K’s 16 lanes (Gen 3). The i7-6800K has 15 MB of shared L3 cache, while the i5-8600K has 9 MB. Release dates are separated by over a year, with the i7-6800K launching on 2016-05-30 and the i5-8600K on 2017-10-04.

Architecture Differences

Both CPUs are built on Intel’s 14 nm process node, but they belong to different microarchitectures. The i7-6800K is based on Broadwell (codename Broadwell-E) and is part of the Core i7 (Broadwell-E) generation. The i5-8600K is based on Coffee Lake and is part of the Core i5 (Coffee Lake) generation. The transistor counts and die sizes are only provided for the i7-6800K, which has 3,400 million transistors on a 246 mm² die; no comparable data is available for the i5-8600K in the fact pack.

The L1 and L2 caches are identical in size per core: 64 KB and 256 KB respectively. The shared L3 cache differs, with the i7-6800K offering 15 MB versus the i5-8600K’s 9 MB. The i7-6800K uses a quad-channel memory interface, while the i5-8600K uses a dual-channel interface, which contributes to the former’s higher memory bandwidth of 76.8 GB/s versus 42.7 GB/s. The i5-8600K includes UHD Graphics 630 integrated graphics, a feature absent from the i7-6800K. Neither processor supports ECC memory. Both have unlocked multipliers for overclocking, though the i7-6800K’s lower boost clock (3.60 GHz) versus the i5-8600K’s (4.30 GHz) suggests different headroom characteristics.

The Verdict

The benchmark data presents a clear trade-off between two six-core CPUs that ultimately land in the same performance percentile. The i7-6800K wins 6 out of 8 head-to-head tests, all of them in Cinebench, with margins of 5.5% to 5.7%. The i5-8600K wins the remaining 2 tests, both in Geekbench, with a narrow 5.2% multicore win and a dominant 18.3% single-core win. The average scores are nearly identical, so the choice depends on workload alignment.

Users whose primary applications resemble Cinebench—multi-threaded rendering, content creation, or video encoding—should prefer the i7-6800K. Its 12 threads and 15 MB of L3 cache, combined with quad-channel memory support at 76.8 GB/s, deliver consistent gains in these tests. The i7-6800K also offers more PCIe lanes (28 versus 16), which may benefit multi-GPU configurations.

Users whose applications resemble Geekbench—general productivity, single-threaded responsiveness, or lightly threaded workloads—should prefer the i5-8600K. Its 4.30 GHz boost clock and newer Coffee Lake architecture yield a substantial 18.3% single-core advantage, which is the largest performance gap between the two. The i5-8600K also runs cooler at 95W TDP versus 140W and includes integrated graphics, making it a more flexible everyday part.

The data does not declare an overall winner because the aggregate scores are too close. Instead, the verdict is workload-specific: the i7-6800K is the Cinebench champion, and the i5-8600K is the Geekbench champion. Both are end-of-life products, so platform availability and the differences in socket and memory support will likely dictate the final choice. If the workload is unknown, the i5-8600K’s single-core dominance and lower TDP make it the safer default, but for rendering-specific tasks, the i7-6800K’s thread advantage is clearly measurable.