I went through this exact headache about six months ago when I built my workstation. Honestly, that 14900K is a beast but it draws so much power during long renders that you really cant cheap out on the board. I started with a mid-range board and my clock speeds were jumping all over the place during 4K exports in Premiere. It was super frustrating. I ended up swapping to the ASUS ROG Strix Z790-E Gaming WiFi II ATX DDR5 and I have been incredibly satisfied with it ever since. The VRMs stay cool even after an hour-long encode because of those massive heatsinks and the 18+1 power stages. If you dont want to spend the full five hundred bucks, there are a few other options that worked well for my colleagues:

• MSI MPG Z790 Carbon WiFi II ATX DDR5
• This is basically the sweet spot for professional work without the ROG tax.
• Gigabyte Z790 AORUS Master X E-ATX
• This one is overbuilt as heck but I have heard no complaints from anyone using it for production. I have had zero stability issues or blue screens with the Strix board tho. It just works well. Tbh, for a 4K editing rig, the extra money for a board that has better power delivery is worth the peace of mind. You dont want a three-hour render failing because the VRMs got too toasty. Ngl, it is a lot of money, but when your deadlines are tight, you will be happy you spent it on something stable.

Ngl that 14900K is basically a space heater masquerading as a CPU. If youre doing heavy 4K renders for hours on end, you definitely need a board that wont buckle under the voltage. I've been using the ASRock Z790 Taichi Lite E-ATX and honestly its the best value for a high-end chip right now. Youre basically getting the $600 flagship specs but for way less because they stripped off the fancy RGB plastic shrouds. It has a 24-phase power delivery which is way more than enough to keep those VRMs cool even when the chip is sucking down 300+ watts during an export. Another solid choice if you want to stay with a standard size is the MSI MPG Z790 Carbon WIFI II. MSI has a really solid BIOS for memory stability which helps a lot with editing workflow crashes. Its got a 19-phase VRM setup and the heatsinks are massive. I wouldnt go much lower than these for an i9 tho. Basically you just want to look at the power stages. Anything over 18 phases with 90A or 105A ratings will keep you from throttling. Also make sure your case has enough airflow over the top of the board... even the best VRMs will eventually cook if the air is stagnant during a six-hour render. Dont overthink the $500+ boards unless you really need 10G lan or specific thunderbolt setups. These mid-high tier ones do the job just fine without the crazy tax.