Re: X299 + i9-99xx cpu temps ?
Those temps are actually inline with what you can expect under a heavy load like rendering. Even at stock speeds that i9 9960X puts out some serious heat. I have an i9 7960X which is for all intents and purposes identical to your i9 9960X save for you having a soldered IHS. You can and should try adjusting the voltage manually in the bios as this will help bring temps in line. For instance my CPU was taking 1.227v at stock speed under load and that's just not required really. I was able to undervolt it to 1.175v and it ran stable I then decided to overclock it on the same voltage and it can actually run 4.6Ghz with that same voltage. My temps were getting out of line (mid 90'sC under load) with the 1.227v that I was using figuring that it was it's stock voltage. After reading around and seeing people undervolting and then overclocking these CPUs I figured I'd try it myself and what a difference.
i9 7960X @ 4.6Ghz H2O // RTX 2080Ti FE H2O // Viotek SUW49C 32:9 Ultra Wide // ASUS Prime X299 Deluxe // 32GB G.Skill Trident Z RGB 3600Mhz // EVGA SuperNova G3 1000w