Nvidia is hoping to grab a lot of GPU design wins in 2012, courtesy of Apple and upcoming Ivy Bridge notebooks, but the outfit is currently struggling to keep up with AMD and Intel in the GPU space.

The introduction of integrated graphics on Sandy Bridge and Llano generation is expected to start slowly chipping away at overall low-end discrete graphics sales, but Nvidia is losing share to AMD at the same time. According to FBR’s quarterly PC system tracker survey, Nvidia’s overall share dropped to 15 from 17 percent over the past 18 months. Since the survey focuses on complete systems, the results should be taken with a grain of salt, as we are not sure how it covered the upgrade/enthusiast retail sales.

However, Nvidia also lost some ground to AMD in the discrete space and it now commands a 41 percent share, down from 45 percent. Curiously, the report found that discrete graphics attach rates have remained largely stable in the notebook market and they even increased in the desktop space over the past 18 months, which seems rather baffling.

FBR offers an explanation, though. Traditional users of low-end desktops are apparently shifting to notebooks, leaving the market to enthusiasts and gamers. At the same time, low-end notebook users are turning to tablets, thus maintaining the discrete GPU share in notebooks. So, if you ever wondered who is buying tablets to begin with, it seems to be people who first realized they didn’t need a desktop and now they are figuring out they can do without notebooks, too.

More here.