Because of the vcore difference i think the sweetspot is 4.9ghz. My temps peaking at 88 c where 4.9ghz and 1.285volt is peaker about 10 c lower. Anything above it will improve your performance of the CPU slightly.

Memory Size: 128 GB (DDR4-2666)Newegg Intel® Core™ i5-9600 Processor 9M Cache, up to 4.60 GHz Buy From $241 Add To Compare Specifications Ordering & Compliance Compatible Products Downloads Support Essentials Download Specifications Product Collection 9th Generation Intel® Core™ i5 Processors Code Name Products formerly Coffee Lake Vertical Segment Desktop Processor Number i5-9600 Although the I5 9600K is a mid-range processor but is still powerful enough to handle heavy workloads, you should pair this processor with a RAM that has at least a speed of 3200MHz as it's compatible with it.

Intel Core i5-9600K 3.70GHz Description: Intel UHD Graphics 630 Class: Desktop Socket: FCLGA1151-2 Clockspeed: 3.7 GHz Turbo Speed: 4.6 GHz Cores: 6 Threads: 6 Typical TDP: 95 W Cache Size: L1: 256 KB, L2: 1.0 MB, 元: 9 MB Memory Support: Max.

Intel i5 9600k drivers