Two weeks ago, Intel CEO Paul Otellini said PC sales bottomed out during the first quarter, and that demand was returning to normal seasonal patterns. AMD last week was a bit more skeptical, with CEO Dirk Meyer saying that there were signs user demand for PCs stabilized during the first quarter. Neither provided a future outlook.

If PC demand doesn't stabilize, GPU shipments could continue to fall. Graphics chip shipments dropped to 74.9 million units during the first quarter of 2009, down 21.1 percent from the same period last year.

Intel was the leading graphics chip vendor, holding a 49.7 market share, though its shipments fell 8.2 percent compared to last year's first quarter. Nvidia was in second place with a 31.1 percent market share, with its shipments falling 25 percent. AMD was in third place with a 17.1 percent market share, and its shipments fell 27.5 percent.

Most of Intel's graphics chips are integrated graphics chipsets. ATI and Nvidia ship GPUs that go on discrete graphics cards.