For what it's worth, the SSD that my DayZ files are on also has Windows 8 Consumer Preview on it. (I usually play on Windows7 on a regular HD accessing the DayZ files on the SSD.) I tried firing up Windows 8 and playing on it and it worked fine! So maybe Ded100let is onto something, maybe it's not a hardware thing but an OS thing? In any case, no amount of tweaking the settings has fixed my Windows 7 install yet.
UPDATE: Never mind, after installing Windows 8.1 on the SSD and playing for 10-15 minutes, I get the same thing only not as severe. i.e. textures disappear, game slows down, but it seems to correct itself after 20-30 seconds. ESCing out to the menu and changing a setting fixes it temporarily, but then it's back again.