HPHT Diamonds were first invented for industrial purposes in the 1950s. CVD Diamonds were first invented in the 1980s. HPHT grows in 14 directions and does not have strain patterns. While CVD Diamonds grow in a single direction and have banded strain patterns. Check here for more characteristics of both lab grown diamonds.
Source: https://abddiamonds.com/cvd-vs-hpht-lab-grown-diamonds-what-are-the-differences/