Temp-wise
 
Custom loop might do better.
Direct die would probably do better.
Lower ambient temps definitely do better.

kelkel1
Temp-wise
 
Custom loop might do better.
Direct die would probably do better.
Lower ambient temps definitely do better.

I wouldn't recommend a Direct Die Contact on the 9900ks for beginning users as the 9900ks is soldered. It depends on your chip and your voltage, but since the 9900ks is binned for 5GHz all turbo, it for sure shouldn't get to 100 c unless you're having a cooler problem. For starters re-apply your paste and re-seat the cooler. Depending on your overclocking experience, I would start at around 1.3V with a -50% vdroop, run stability test adjusting your voltages until you find something that's stable and then start adjusting the vdroop to be lower. It's all in silicon lottery, I've had chips that can undervolt and hit high clocks, and I've had some at 1.4 volts that barely maintain 5GHz. 
 
If you're temps are still high after that, a different cooling solution may be needed. There also may be other settings you can adjust like your PL's and the such that someone may chime in eventually on this post.