Typically ASUS is the #1 motherboard manufacturer, they always ship more units than their competitors. Trailing behind is always Gigabyte, but it looks like they were able to claim the #1 spot for the first quarter of 2015.
For the period of January – March of this year Gigabyte was able to send out 4.8 million units, while ASUS only sent out 4.5 million. With such low demand for motherboards in Europe and China motherboard manufactures are expected to see shipments decline in 2015. ASUS and Gigabyte specifically are expected to miss their 20 million-unit shipping target for the year.
The drop in motherboard sales has been attributed to the rise of tablets and smartphones, which has made the PC market even smaller over the past year. Also you have the fact that Intel’s Skylake platform is a ways away and no one really has a need to upgrade from Haswell currently.
ASRock is actually making moves into the gaming notebook market in an effort to compesate for shrinking motherboard demand.