TAIPEI – Printed circuit board manufacturers Gigabyte Technology and ASRock posted third-quarter shipment growth of 20% to 40%.

Fourth quarter shipments are expected to be flat, however, as a result of modest impact from Windows 8, say published reports.

Gigabyte’s September PCB motherboard shipments were 1.7 million to 1.8 million units, down about 10% sequentially. Revenues were $147.66 million, up 0.99% compared to August, and up 12.7% year-over-year. The firm’s third-quarter PCB shipments totaled 5.5 million units, up 22% sequentially.

Gigabyte’s fourth-quarter PCB motherboard shipments are expected to drop 10% to 15%. The firm’s ODM business accounted for 15% to 20% of overall revenues last year, but fell to less than 15% in 2012.

ASRock’s PCB motherboard shipments were 2.2 million units, up 46.7% and 10% from the second quarter and the first quarter, respectively. The company’s revenue growth was less than 40% in the third quarter. In the first nine months of 2012, ASRock’s PCB motherboard shipments were 5.7 million units, peaking in September.