Intel Core i5-6600K vs Intel Core i7-4790S Comparison

The Intel Core i7-4790S and Intel Core i5-6600K represent two distinct philosophies from Intel's desktop lineup: the former a power-efficient 65W Haswell part with Hyper-Threading, the latter a higher-TDP Skylake chip with an unlocked multiplier. Benchmark results show a sharp split: the i7-4790S dominates in Cinebench workloads across all versions, while the i5-6600K takes decisive wins in Geekbench. This makes the choice highly dependent on the specific application, as the data shows no single overall victor in the synthetic suite.

Where Each One Wins

The Intel Core i7-4790S wins outright in every Cinebench test included in the data, both single-core and multi-core. In Cinebench R15, R20, and R23, the i7-4790S scores 595, 2482, and 5911 respectively in multi-core tests, versus 540, 2252, and 5363 for the i5-6600K. The single-core Cinebench results follow the same pattern: the i7-4790S posts 84 in R15, 350 in R20, and 834 in R23, while the i5-6600K manages 76, 317, and 757. Across all six Cinebench tests, the i7-4790S holds a consistent margin of roughly 10% over its rival. This suggests that for rendering tasks, which Cinebench simulates, the i7-4790S’s extra threads (8 versus 4) provide a measurable advantage that outweighs any architectural efficiency gains from the newer Skylake design.

The Intel Core i5-6600K, conversely, wins both Geekbench tests. It scores 3856 in Geekbench multi-core and 1363 in single-core, compared to 3307 and 1056 for the i7-4790S. The delta is substantial: the i5-6600K leads by 14.2% in multi-core and 22.5% in single-core. Geekbench exercises a broader mix of integer, floating-point, and memory operations, and here the Skylake architecture’s higher base clock (3.50 GHz versus 3.20 GHz) and newer design clearly pay off. The i5-6600K’s wins are not marginal; they are the largest deltas in the entire head-to-head dataset, indicating a fundamentally stronger showing in these specific workloads.

Architecture Differences

The two processors come from different generations and sockets, which dictates much of their behavior. The i7-4790S is a Haswell part on Intel Socket 1150, built on a 22 nm process with 1,400 million transistors on a 177 mm² die. The i5-6600K is Skylake on Intel Socket 1151, using a 14 nm process; its transistor count and die size are not listed in the data. The process node shrink from 22 nm to 14 nm is significant, but the i7-4790S compensates with a higher core count in terms of threads: it has 4 cores and 8 threads, while the i5-6600K has 4 cores and 4 threads. This is the single most important architectural differentiator for multi-threaded performance.

Cache configurations also differ. Both have 64 KB L1 and 256 KB L2 per core, but the i7-4790S has 8 MB of shared L3 cache versus 6 MB on the i5-6600K. That extra 2 MB of L3 helps the i7-4790S in workloads that benefit from larger working sets. Memory support is another divergence: the i7-4790S supports only DDR3 with dual-channel memory and a bandwidth of 25.6 GB/s, while the i5-6600K supports both DDR3 and DDR4, also dual-channel, but with a higher bandwidth of 34.1 GB/s. The i5-6600K’s memory flexibility and higher bandwidth are clear advantages for memory-sensitive tasks.

Other differences include the integrated graphics: the i7-4790S has Intel HD 4600, while the i5-6600K has HD Graphics 530. Both are end-of-life products, and neither supports ECC memory. The i5-6600K has an unlocked multiplier, meaning it can be overclocked, whereas the i7-4790S is locked. The i5-6600K also has a higher TDP of 91W versus 65W for the i7-4790S, reflecting its higher base clock of 3.50 GHz compared to 3.20 GHz. Interestingly, the boost clocks are close: 3.90 GHz for the i5-6600K and 4.00 GHz for the i7-4790S. Both use PCIe Gen 3 with 16 lanes from the CPU.

Head-to-Head Benchmarks

The Cinebench results paint a consistent picture of i7-4790S superiority. In Cinebench R15 multi-core, the i7-4790S scores 595 against 540 for the i5-6600K, a 10.2% lead. The single-core R15 test shows a similar 10.5% margin (84 versus 76). These deltas are nearly identical across R20 and R23: multi-core scores of 2482 versus 2252 and 5911 versus 5363, each a 10.2% difference; single-core scores of 350 versus 317 and 834 versus 757, each a 10.2% or 10.4% difference. The consistency of these margins suggests a stable performance offset, likely driven by the i7-4790S’s higher boost clock (4.00 GHz versus 3.90 GHz) and Hyper-Threading, which matters even in single-core tests due to better thread scheduling.

The Geekbench results invert the picture completely. In Geekbench multi-core, the i5-6600K scores 3856, a 14.2% improvement over the i7-4790S’s 3307. The single-core gap is even larger: 1363 versus 1056, a 22.5% delta. These are the largest win margins in the entire comparison, indicating that the i5-6600K’s Skylake architecture, with its higher base clock and newer memory controller, delivers a substantial performance uplift in integer and floating-point workloads that Geekbench stresses. Notably, despite having half the threads, the i5-6600K still beats the i7-4790S in Geekbench multi-core, which shows that raw core count is not always decisive when architectural efficiency and clock speed are superior.

The data also shows that both CPUs sit at the 42nd percentile among all CPUs, with average benchmark scores of 1827 for the i7-4790S and 1816 for the i5-6600K. Their nearest rivals are clustered closely: the i7-4790S is within 0.2% of the Intel Xeon D-1537, Xeon E5-2608L v3, and Core i5-8305G, while the i5-6600K is within 0.4% of the Xeon E3-1505M v5, AMD Ryzen 5 PRO 4650U, and Core i3-9320. This indicates that despite their internal differences, both are mid-pack performers in the broader CPU landscape.

The Verdict

From the benchmark data alone, the Intel Core i7-4790S is the clear choice for rendering and multi-threaded content creation workloads. Its consistent 10% lead across all Cinebench versions, coupled with a lower 65W TDP, makes it a compelling option for users who prioritize sustained multi-core performance without the power draw of the i5-6600K. The i7-4790S also has a slight boost clock advantage (4.00 GHz versus 3.90 GHz) and double the threads, which explains its Cinebench dominance.

The Intel Core i5-6600K, however, is the better pick for general-purpose computing, as measured by Geekbench. Its 14.2% multi-core and 22.5% single-core leads are decisive, and its support for DDR4 memory and higher memory bandwidth (34.1 GB/s versus 25.6 GB/s) give it a future-proofing edge. The unlocked multiplier also allows for overclocking, which could extend its lead further, though no overclocked figures are in the data. Users who value memory flexibility, higher memory bandwidth, and stronger Geekbench scores should choose the i5-6600K.

The verdict hinges on the workload. For Cinebench-style rendering, the i7-4790S wins six out of eight tests. For Geekbench-style system benchmarks, the i5-6600K wins the remaining two by large margins. Neither CPU is objectively superior across the board; the data supports a use-case-driven decision. The i7-4790S is the multi-threaded workhorse, while the i5-6600K is the more balanced, modern performer with a higher ceiling for memory-bound and single-threaded tasks.

FAQ

Q: Which CPU wins more benchmark tests overall?

A: The Intel Core i7-4790S wins 6 out of 8 head-to-head tests, all in Cinebench. The Intel Core i5-6600K wins 2 tests, both in Geekbench.

Q: What is the biggest performance gap between the two CPUs?

A: The largest delta is in Geekbench single-core, where the Intel Core i5-6600K leads by 22.5% (1363 versus 1056). The smallest gap is in Cinebench R15 multi-core, where the i7-4790S leads by 10.2% (595 versus 540).

Q: Does the i5-6600K have more threads than the i7-4790S?

A: No. The i7-4790S has 8 threads (4 cores), while the i5-6600K has 4 threads (4 cores). The i7-4790S has double the thread count.

Q: Which CPU has a higher memory bandwidth?

A: The Intel Core i5-6600K has a memory bandwidth of 34.1 GB/s, compared to 25.6 GB/s for the i7-4790S. The i5-6600K also supports both DDR3 and DDR4, while the i7-4790S supports only DDR3.

Q: Is the i5-6600K overclockable?

A: Yes, the i5-6600K has an unlocked multiplier. The i7-4790S has a locked multiplier and cannot be overclocked.

Q: How do the two CPUs compare in terms of power consumption?

A: The i7-4790S has a TDP of 65W, while the i5-6600K has a TDP of 91W. The i7-4790S uses less power despite having more threads and a higher boost clock.