The Core i5 Doldrums
It used to be that Core i5 processors represented the best choice for mainstream users looking for value-oriented pricing, high performance, and modest power consumption. But now, fast Ryzen 5 CPUs often prove superior. Intel did increase the core count of its Coffee Lake-based Core i5s by 50 percent to grapple with AMD's first-gen Ryzen 5 chips. However, the latest round of Ryzen 5 models is even faster, particularly in threaded workloads.
Intel's ninth-gen Core i7 and Core i9 processors come with more cores, too. Unfortunately, the Core i5-9600K we're reviewing today does not. It includes the same six cores as its predecessor, along with a price tag that lands between Ryzen 5 2600X and Ryzen 7 2700. Worse, both competing CPUs are bundled with coolers, while Intel makes you buy your own.
The story isn't all bad for Intel. It did switch to a solder-based thermal interface material between its die and heat spreader, enabling higher multi-core Turbo Boost frequencies. But those incremental improvements are hardly earth-shattering.
Choosing between a Core i5-9600K and Ryzen presents the same conundrum we've faced in the past: it depends on the type of software you run most frequently. If you're a gamer who doesn't really venture beyond 1920x1080, Intel's Core i5-9600K is the chip for you. But if a majority of your workloads are threaded in nature, including content creation and productivity, a powerful Ryzen gets you more performance at a competitive price.
AMD has also launched its Ryzen 3000-series processors. The updated Ryzen line-up employs a smaller 7nm process that should confer power and price benefits. It'll also wield the new Zen 2 microarchitecture, which is expected to boost performance while Intel remains mired in a derivative of the seven-year-old Skylake design. These chips have now taken our Best CPUs list by storm, so be sure to head there for a list of the latest leading processors.
Intel Core i5-9600K
The ~$263 Core i5-9600K lands between the $299 Ryzen 7 2700 and $225 Ryzen 5 2600X. Inexplicably, Intel raised the -9600K's price by $5 compared to its previous-gen Core i5-8600K.
| Core i9-9900K | Core i7-9700K | Core i5-9600K | |
| Architecture | Coffee Lake | Coffee Lake | Coffee Lake |
| Socket | 1151 | 1151 | 1151 |
| Cores / Threads | 8 / 16 | 8 / 8 | 6 / 6 |
| Base Frequency (GHz) | 3.6 | 3.6 | 3.7 |
| Boost Frequency ( Active Cores - GHz) | 1-2 Cores - 5.0, 4 Cores - 4.8, 8 Cores - 4.7 | 1 Core - 4.9, 2 Core 4.8, 4 Core 4.7, 8 Core 4.6 | 1 Core - 4.6, 2 Core - 4.5, 4 Core 4.4, 6 Core 4.3 |
| L3 Cache | 16MB | 12MB | 9MB |
| Process | 14nm++ | 14nm++ | 14nm++ |
| TDP | 95W | 95W | 95W |
| Memory Speed | DDR4-2666 | DDR4-2666 | DDR4-2666 |
| Memory Controller | Dual-Channel | Dual-Channel | Dual-Channel |
| PCIe Lanes | x16 | x16 | x16 |
| Integrated UHD Graphics GT2 (Base/Boost MHz) | 350 / 1200 | 350 / 1200 | 350 / 1150 |
| Recommended Customer Pricing | $488 - $499 | $374 - $385 | $262 - $263 |
Intel manufactures the -9600K on its 14nm++ process. In addition to six execution cores (without Hyper-Threading technology), the chip includes an integrated UHD 630 graphics engine, sports unlocked ratio multipliers for easy overclocking, and supports two channels of DDR4-2666 memory. Like the Core i5-8600K that preceded it, the -9600K comes equipped with 9MB of L3 cache and a 95W thermal design power rating.
| Active Cores | Base | 1 Core | 2 Cores | 3 Cores | 4 Cores | 5 Cores | 6 Cores |
| Core i5-9600K (GHz) | 3.7 | 4.6 | 4.5 | 4.4 | 4.4 | 4.3 | 4.3 |
| Core i5-8600K (GHz) | 3.6 | 4.3 | 4.2 | 4.2 | 4.2 | 4.1 | 4.1 |
Intel does dial up the -9600K's Turbo Boost frequencies quite a bit, though. Solder-based thermal interface material improves heat transfer, facilitating higher frequencies whether you're using one core or all six. A base clock rate of 3.7 GHz already represents a 100 MHz improvement over the Core i5-8600K frequency floor, and you get as much as a 300 MHz speed-up when multiple cores are utilized.
We didn't see the need for extreme cooling with Intel's Core i5-9600K, even during our overclocking efforts. The processor held a steady 80°C under five hours of Prime95 optimized for AVX instructions, and ~64°C during a series of non-AVX tasks. Granted, we did use a beefy Corsair H115i cranking away at full speed. But you shouldn't have any trouble cooling the processor at stock settings. Overclocking is fine with a capable closed-loop liquid cooler.
| Model | Cores / Threads | Base Frequency | Boost Frequency | Memory Support | PCIe Lanes | Cache | TDP | Price |
| Core i9-9900K | 8 / 16 | 3.6 GHz | 5 GHz (1 / 2 Core)4.8 GHz (4 Core)4.7 GHz (6 / 8 Core) | DDR4-2666 | 16 | 16MB | 95W | $488 |
| Ryzen 7 2700X | 8 / 16 | 3.7 GHz | 4.3 GHz | DDR4-2966 | 16 + 4 (NVMe) | 16MB | 105W | $329 |
| Core i7-9700K | 8 / 8 | 3.6 GHz | 4.9 GHz (1 Core)4.8 GHz (2 Core)4.7 GHz (4 Core)4.6 GHz (6 / 8 Core) | DDR4-2666 | 16 | 12MB | 95W | $374 |
| Core i7-8086K | 6 / 12 | 4.0 GHz | 5.0 GHz | DDR4-2666 | 16 | 12MB | 95W | $425 |
| Core i7-8700K | 6 / 12 | 3.7 GHz | 4.7 GHz | DDR4-2666 | 16 | 12MB | 95W | $330 |
| Ryzen 7 2700 | 8 / 16 | 3.2 GHz | 4.1 GHz | DDR4-2966 | 16 + 4 (NVMe) | 16MB | 95W | $299 |
| Core i5-9600K | 6 / 6 | 3.7 GHz | 4.6 GHz (1 Core)4.5 GHz (2 Core)4.4 GHz (4 Core)4.3 GHz (6 Core) | DDR4-2666 | 16 | 9MB | 95W | $262 |
| Core i5-8600K | 6 / 6 | 3.6 GHz | 4.3 GHz | DDR4-2666 | 16 | 9MB | 95W | $279 |
| Ryzen 5 2600X | 6 / 12 | 3.6 GHz | 4.2 GHz | DDR4-2966 | 16 + 4 (NVMe) | 16MB | 65W | $225 |
| Ryzen 5 2600 | 6 / 12 | 3.4 GHz | 3.9 GHz | DDR4-2966 | 16 + 4 (NVMe) | 16MB | 65W | $199 |
The Core i5-9600K drops into existing 300-series motherboards after a BIOS update. Most, if not all of them, should support Core i5-9600K and its power requirements quite easily, though you might want to steer away from the lowest-cost models if you plan on overclocking.
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