I used it on a 2700x with no problems so pretty sure that you’ll be ok with a 2600x. As for the updated bios, it will give you more ram compatibility. I came to understand that Ryzen processors work best with faster ram. Do your research and choose ram that’s in the compatibility list or learn to tweak the settings in BIOS. Likewise you can wait and pay just a few dollars more for the b450-max motherboard that will come with the latest bios. Cheers