Overclocking the Core i7-8700K (Coffee Lake) to 5.0GHz on all 6 Cores

Test Setup

For our tests, we used a test rig which includes the Asus ROG Maximus X Hero motherboard, along with an Intel Core i7-8700K (Coffee Lake) at default clock speed of 3.7GHz (turbo boost 4.5GHz), as well as 8GB of G.Skill Trident-Z DDR4-3200 ram in dual channel mode.

All tests were conducted at turbo clock speeds of 4.5GHz at a resolution of 1920×1080. High or Ultra settings enabled.


CPU Intel Core i7-8700K (Coffee Lake) @ 3.7GHz / Turbo @ 4.5GHz
Overclock All cores at x50, vCore at 1.35V – Result: 5.0GHz
Cooling Cooler Master MasterLiquid Pro 240
Motherboard Asus ROG Maximus X Hero
Ram 2 x 4GB G.Skill Trident-Z DDR4-3200
XMP 2.0 profiles Memory timings : 15-15-15-35 @1.35v
SSD/HDD Patriot Hellfire PCIE M.2 256GB SSD
PSU Thermaltake Toughpower RGB 750W
VGA card Zotac GeForce GTX 1080 8GB GDDR5
Nvidia Drivers Latest GeForce Drivers v.388.13 – WHQL
OS Windows 10



Load Temperatures

During our stress test, the load temperatures reached a high of 89 degrees Celsius. It’s fairly high, but what we expected … we highly recommended a very good CPU cooler. We suggest investing a custom water cooling or a large AIO unit.



Passmark 9

Fast, easy to use, PC speed testing and benchmarking. PassMark PerformanceTest allows you to objectively benchmark a PC using a variety of different speed tests and compare the results to other computers.



Cinebench R15

CINEBENCH is a real-world cross platform test suite that evaluates your computer’s performance capabilities. CINEBENCH is based on MAXON’s award-winning animation software Cinema 4D, which is used extensively by studios and production houses worldwide for 3D content creation. MAXON software has been used in blockbuster movies such as Iron Man 3, Oblivion, Life of Pi or Prometheus and many more. CINEBENCH is the perfect tool to compare CPU and graphics performance across various systems and platforms (Windows and OS X).


PCMark 10

PCMark 10 is the latest in our series of industry standard PC benchmarks. Updated for Windows 10 with new and improved workloads, PCMark 10 is also faster and easier to use. PCMark 10 features a comprehensive set of tests that cover the wide variety of tasks performed in the modern workplace. With express, extended, and custom run options to suit your needs, PCMark 10 is the complete PC benchmark for the modern office and an ideal choice for organizations that buy PCs in high volumes.




3DMark Time Spy is a new DirectX 12 benchmark test for Windows 10 gaming PCs. Time Spy is one of the first DirectX 12 apps to be built “the right way” from the ground up to fully realize the performance gains that the new API offers. With its pure DirectX 12 engine, which supports new API features like asynchronous compute, explicit multi-adapter, and multi-threading, Time Spy is the ideal test for benchmarking the latest graphics cards.




Fire Strike is a showcase DirectX 11 benchmark designed for today’s high-performance gaming PCs. It is our most ambitious and technical benchmark ever, featuring real-time graphics rendered with detail and complexity far beyond what is found in other benchmarks and games today.


Final Thoughts

And there you go. How to overclock an Intel Core i7-8700K (Coffee Lake) to 5.0GHz on all 6 cores … simply by changing 3 BIOS options on the Asus ROG Maximus X Hero Motherboard. Remember, there’s NO guarantee that you’ll get 5.0GHz or higher, as it all depends on several important factors such as your power supply, cooling solution and of course, the correct BIOS settings. Some overclockers like to bump up their DDR4 ram, which can give you anything between 5-10% extra performance. If you’ve got the time and patience, you should play around with it until you hit a sweet spot.

Happy overclocking …


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About Winston 3850 Articles
Winston has over 20 years of experience in the I.T. Industry. He launched Funky Kit with the aim to capture a wider audience worldwide. His knowledge in PC hardware is very distinguished, not only publishing enjoyable reviews but also writing great articles.