Core i7 8700K OC at 4800 MHz 1.3 volts

1.3 V and higher voltages can cause serious problems for Coffee Lake CPUs because of the TIM used under the heat spreader (instead of a solder like in the Sandy Bridge range). Our (delidded) Core i7 8700K was set @ 4800 MHz, at 1.3 volts. Again, wPrime 2.10 (3 times 1024 M) has been used.

IDLE temperature measurements are taken in the desktop, with almost no stress to the CPU.

The temps shouldn’t go beyond 90°C, as otherwise the CPU might degrade and also throttling can occur (especially applicable to the AMD Ryzen range, which normally operates at lower temperatures). AIO coolers perform very well with our delidded Core i7 8700K. The Gammaxx L240 2 is doing quite nicely. Let’s try it with a voltage higher than 1.3 V. 

So, what will the situation look like after more overclocking? There are some changes when the voltage is cranked up, but it’s nothing spectacular, and you cannot really tell the difference in noise. It was possible to take the processor up to 1.4 Volts with this cooler (good for OC on the i7 8700K up to 5 GHz or even more), but 1.45 V was too much to handle (over 90 degrees).

There are five stages:

• Default
• 4.8 GHz @ 1.3 V
• 4.8 GHz @ 1.35 V
• 4.8 GHz @ 1.4 V
• 4.8 GHz @ 1.45 V

The Deepcool AIO managed to keep the CPU temperatures under control until 1.4 V. At 1.45 V it already went above 90 degrees Celsius, but the final result is still very nice and most users shouldn’t complain.