Worldwide PC shipments took a plunge last quarter, as expected, according to new figures from IDC and Gartner.

IDC on Tuesday said shipments totaled 71.9 million units in the fourth quarter of 2015, a year-on-year decline of 10.6 percent. The same day, Gartner reported similar, but slightly more optimistic figures: 75.7 million units shipped last quarter, for an 8.3 percent decline from the fourth quarter of 2015.

This, according to Gartner Principal Analyst Mikako Kitagawa, is fifth consecutive quarter of worldwide PC shipment declines. "Holiday sales did not boost the overall PC shipments, hinting at changes to consumers' PC purchase behavior," Kitagawa added. Plus, "Windows 10 migration was minor in the fourth quarter as many organizations were just starting their testing period."

For 2015 overall, PC shipments totaled 288.7 million units, an 8 percent drop from 2014, Gartner said. IDC, meanwhile, put the 2015 year-on-year drop north of 9.8 percent, calling it "the largest in history," surpassing 2013's former record.

On a more positive note, IDC Worldwide PC Tracker Vice President Loren Loverde said the situation shouldn't be as bad this year. Commercial adoption of Windows 10 is "expected to accelerate," and consumer buying will "stabilize" by the second half of 2016.

"PC replacements should pick up again in 2016, particularly later in the year," Loverde said in a statement. "Most PC users have delayed an upgrade, but can only maintain this for so long before facing security and performance issues. We continue to believe that a majority of these users will purchase another PC, motivated by new products and attractive pricing."