PC sales right now. REUTERS/Steve Dipaola PC sales are continuing to crash: New data from two research firms shows that the industry is declining fast, with a drop in sales year-on-year of about 10%.

On Wednesday, both Gartner and IDC published estimates for PC shipments in the second quarter of 2015 — and it makes for unpleasant reading for hardware vendors.

Gartner says sales have dropped by 9.5% over the past year, while IDC's data is even more alarming — predicting a year-on-year decline of 11.8%.

The Wall Street Journal (where we first saw the data) points out this disparity is due to the fact that Gartner includes "ultramobile premium devices" (aka certain tablet devices) in its figures, while IDC does not.

Gartner estimates negative growth for every major PC hardware vendor: Lenovo, the market leader, dropped by 6.8%, while Acer Group saw the biggest fall — a 20.2% decline. Overall, shipments dropped to 68.4 million, down from 75.6 million a year before.

Meanwhile, IDC's data shows a more aggressive decline. Apple, which is not included in Gartner's global data, is the only company to see any increase year-on-year. IDC's figures paint an even bleaker picture for Acer Group: a 26.9% decline. They put Q2 2015 shipments at 66.1 million, down from 75 million in 2014.

This shouldn't necessarily be interpreted as a coup for Apple, however. Gartner does include Apple in its figures for shipments within the US, its home market — and there the Cupertino company is facing a 2.5% decline.

Lenovo has attempted to put a brave face on the news. In a statement, president and COO Gianfranco Lanci says the data shows "continued growth of our market share in our core PC business, which is a strong, powerful growth engine for the company." He says the company has "ample opportunity for continued growth" in the sector — despite the fact that while its percentage market share is increasing, its real-term shipment numbers are dropping.

This, as The Wall Street Journal points out, is the biggest drop in almost two years (2.6% in 2012, 11.1% in 2013, 0.8% in 2014). Gartner identifies three factors as contributing to this latest decline:

"A sharp appreciation of the US dollar against local currencies" is one, according to principal analyst Mikako Kitagawa — making PCs more expensive. "The worldwide PC market experienced unusually positive desk-based growth last year due to the end of Windows XP support. After the XP impact was phased out, there have not been any major growth drivers to stimulate a PC refresh." The coming launch of Windows 10. Kitagawa says: "The Windows 10 launch scheduled for 3Q15 has created self-regulated inventory control. PC vendors and the channels tried clearing inventory as much as possible before the Windows 10 launch." In short, people aren't buying PCs as they wait for the latest OS from Microsoft — further denting sales.

Overall, Gartner is forecasting a decline of 4.4% in PC shipments throughout 2015. The research firm expects the industry to return to "slow and steady growth in 2016." But the data is clear: The age of the PC is over.