Based on the Comet Lake microarchitecture, the i9-10900K could be the last flagship processor to come out of Intel's 14nm process node. The processor has 10 cores, 20 threads, and rumors point to a 20MB cache.
The 3DMark result detected the i9-10900K with a 3.7 GHz base clock and 5.1 GHz boost clock, which coincide with the figures from a previous leak. The 5.1 GHz reportedly corresponds to the 10-core chip's single-core boost clock. However, the i9-10900K is rumored to exploit Intel's Turbo Boost Max Technology 3.0 and Thermal Velocity Boost (TVB) features, which will enable it to boost to 5.2 GHz and 5.3 GHz, respectively.
The i9-10900K will only fit inside Intel's new LGA1200 socket, so it will require you to buy a new motherboard based on one of the 400-series chipsets. However, you will be able to reuse your cooling solution since CPU coolers that support the LGA115x socket should work fine on the LGA1200 socket since both seeming have identical dimensions and mounting holes. That should be the least of your worries though. The big question is whether your CPU cooler can handle the i9-10900K's hotness.
One early report suggests that the i9-10900K's maximum power consumption is off the charts. When pushed to the limit, the 10-core chip is rumored to draw over 300W. That's a jaw-dropping number considering that would put the i9-10900K's power consumption in the same ballpark of the AMD Ryzen Threadripper 3970X 32-core monster.
Intel is expected lo launch the Comet Lake desktop processors in the middle of April. It won't be long before we see whether the chipmaker was successful in optimizing the i9-10900K's power consumption to a reasonable limit.