Intel once again increased its lead over arch-rival AMD during Q1, as its share of world x86 chip sales rose above 80 per cent - the first quarter it's done so since Q3 2005.

The figures come from market watcher iSuppli, which put Intel on 80.2 per cent and AMD on 11.1 per cent. AMD's share fell from 15.7 per cent in the previous quarter, when Intel commanded 75.7 per cent of the market.

The x86 business is a classic two-horse race: when Intel falls, AMD rises - and vice versa. The two companies' marketshares remained largely static throughout 2004 and the first half of 2005, but during Q3 and Q4 of that year AMD began to erode Intel's lead. AMD's marketshare rose to a maximum of 16.7 per cent - Intel was on 73.2 per cent - in Q3 2006.

Since then, the tables have turned and Intel has been winning lost share back from AMD, quarter after quarter, iSuppli's numbers show.

Q2's numbers seem unlikely to show any change to that trend, given the boost Intel will have taken from this week's Developer Forum announcements and, more importantly, next month's next-gen Centrino launch.

But AMD is expected to revamp its desktop and server processor lines in Q3, a move that may flip the balance.