Overclock your CPU, but not your GPU unless you have hours upon hours of time tinkering. Typically turn off high levels of antialiasing and disable water effects in games for speed.
Overclock your CPU if it is a chip begging to overclock. Some chips beg for it. I always run my cheap Intel Core i7-8700K 3.7 GHz 6-Core Processor (12 thread) at a staggering 5.0 Ghz.
Never try to overclock RAM on either motherboard or CPU. Ever. (use the XMP profile if it has a rated one).
I never tried stability tests of my 5 Ghz 3700K at higher speeds but theoretically, one in 35 chips will run at 5.3 on water pump. (Yes I use a cheap water pump on this cheap chip).
If you use liquid Nitrogen instead of water, and get a lucky chip, you can get the speed to 7.4 Ghz instead of 5 Ghz !!! :
https://www.pcgamer.com/overclocker-bathes-core-i7-8700k-in-ln2-and-doubles-clockspeed-to-74ghz/I always buy overclockable versions of GPUs but do not overclock GPUs because I need to trust them for OpenCL and other computation. I have a 1080 TI and did not have to pay $1,500 for it, I cried and whined at a store and got it new for 741 dollars due to a variety of store circumstances. A 1080TI is supposed to be the fastest but as of March 4 2018 it is only 3.00 times faster than a Nvidia 770 for math computation benchmarks. Just three times faster.
If you dont want to delid your chip yourself (needed to get 5.0Ghz to 5.3 on water), you can buy a 5.3 Ghz rated 6 core chip from siliconlottery (a delid and binning service) but this week they removed the 5.3 listing and offer 5.2s only :
https://siliconlottery.com/collections/coffeelakeUsing no heat sink and no water pump (air pocket mistake), will result in the 8 temperature sensors protecting the i8700k chip in turning down its speed dramatically within 3 seconds once it hits 99centigrade. I tested this to death endlessly. With vertical radiator , two aftermarket high pressure low noise fans, and in a cold michigan home, I see idle temps of chip of 23C and peak temps in stress benchmarks of a laughably coldish 46C , ever, as in peak.
Overclocking is also for silence, in normal operations, you can have nearly every fan almost off in the entire machine, the fans totally OFF in powersupply, and the three 1080yi fans totally off.
Its not as quiet as a real apple product due to faint sound of water pump, but I suggest everyone here to rush out and but a 6 core i8700K or wait a year for the cheap home-gamer 8 cores coming out (Icelake).
You must delid, or use SiliconLottery.com for chips begging for it. Some chips really really are easy to delid (and relid) and I got 21C drop to 19C drop from delidding alone. Shame on intel.
If you buy a new pc meant for i8700k (called z370 boards), get NVMe (or NVMe(s)) for it not much slower SSDs.
The comment above about aging chips or stressing them is misinformed. They do not die sooner. The overclock chemicals last shorter vs thermal grease, but that can be reapplied. The chips never run faster than one 40th speed, unless doing actual work. they nap relentlessly. A tool that shows actual napping states will reveal this to you on mac or windows. It runs at 5Ghz only when something majorly useful to do.
And even that does not burn it out. It is true the gates on the silicon are an average of 2.5 atoms thick in height and 11 atoms wide, but electrons bump to travel and the flow of electricity and heat do not age the chip. cutting all power and applying power to a cold chip tens of thousands of times can harm it though.