Desktop share didn't change this quarter, but AMD has gained 4.8 points of share on year from both Intel and VIA, entirely due to Ryzen's growth. The flat share is due to both Intel and AMD having proportional lower shipments in the second quarter for differing reasons. Intel had supply constraints on low-end CPUs, and AMD was transitioning from Ryzen 2000 to Ryzen 3000 products and transitions usually cause a small dip as inventory is burned off and the new products ramp up. - Dean McCarron, Mercury Research
Tom's Hardware has an overview of the full Mercury Research report over here.