Major Taiwanese CD-R disc makers are scaling up 48x disc production, with some advancing into 52x discs, while small manufacturers still struggle to improve yield rates for high-speed products. After starting 48x volume production in the summer, major disc makers Ritek, CMC Magnetics and Prodisc Technology said 48x discs will comprise nearly all of their CD-R shipments in the fourth quarter. CMC and Prodisc also indicated aggressive plans to convert production lines to make 52x discs. Some small and medium-sized manufacturers have just entered volume production for 48x discs, but yield rates remain a major issue.