You could return your brand new 3900x and borrow your friends 2600x while you wait for the new 5900x. If this sounds oddly specific, it's because it is exactly

You could return your brand new 3900x and borrow your friends 2600x while you wait for the new 5900x. If this sounds oddly specific, it's because it is exactly what I am doing. Returned the 5900X a couple months ago while I wait. Obviously this isn't a serious suggestion as I know most people don't happen to have a friend with a spare 2600x.