Yes, it will cool it just fine. i9 9900k is rated at only 95w TDP stock, so unless you are planning a rather serious overclock you don't need much cooling .. not to mention ithat is just another Asetek CLC using pumps that flow at best about what a healthy adult can urinate (40-60L/h) compared to arguably the most popular custom loop pump being able to move 1500L/h. CLCs are not only limited in cooling by cheap aluminum radiator sizes, but also by extemely low coolant flow rates compared to real water cooling.