Someone who had access to an Intel Core i7-9700K was able to overclock it to 5.30 GHz on all cores, even more impressive is that this was done with air cooling. Someone posted blurrycam pictures of their setup and a CPU-Z screenshot showing 8-core / 8-thread config and 12 MB of L3 cache, confirming that it is an i7-9700K. The chips multiplier is dialed up to 53.0X and the voltage is at 1.215V.
Besides the overclock, which is good, the main thing here is that this overclock was achieved on air cooling. While we can’t tell which air cooler is being used by the blurry photo, it seems to be very mainstream and not that large. When overclocking a Core i7-8700K you need at least an AiO to achieve anything close to 5.30 GHz.
This could be a testament to the soldered IHS that the i7-9700K has or the effect of lack of HyperThreading.