Following up on IDC's estimates on PC shipments in the fourth quarter, market researcher Gartner (IT -1.05%) has now put out its own figures on how poorly the broader PC market is faring. There's some disagreement between the two, but the consensus is that investors are still looking at a market in decline.

If you recall, Gartner figures show Hewlett-Packard (HPQ 0.11%) losing its crown as the top PC maker in the world by unit volumes in the third quarter, ceding that title to Lenovo after the latter slid ahead by just over 200,000 units. Following the third-quarter decline of 8.3% in global PC shipments as consumers and companies alike anxiously awaited the transition to Microsoft (MSFT -2.45%) Windows 8, the PC market just shrank a little bit more.

Sorry, PC
This time around, we're talking about a decline of 4.9% (versus IDC's negative 6.4% estimate). HP was able to retake its crown from Lenovo and become king of the PC hill just in time for the tablet market to bulldoze a hole through it. Dell's (DELL.DL) shipments plunged by 20.9%, which is about what IDC also found.

Vendor

Q4 2012 Worldwide Unit Shipments

Q4 2012 Worldwide Market Share

Growth (YOY)

HP

14.6 million

16.2%

(0.5%)

Lenovo

14 million

15.5%

8.2%

Dell

9.2 million

10.2%

(20.9%)

Acer

8.6 million

9.5%

(11%)

Others

37.4 million

41.4%

(6.4%)

Total

90.4 million

100%

(4.9%)

Source: Gartner. Figures may not add up due to rounding. YOY = year over year.

In order to boost its market share, it's possible that HP sacrificed margins and the PC giant participated in the broad rollout of new Windows 8 devices. HP's personal systems group remains its biggest revenue generator, but also its lowest margin division, so the segment can't very well afford margin declines.

Echoing IDC's findings, Gartner says Windows 8 was unsuccessful in boosting overall PC volumes. The researcher said that PC OEMs were "lackluster" in their form factor designs and are mostly missing out on the potential in touch interfaces.

Domestic discrepancy
Gartner and IDC have some discrepancies when it comes to their respective domestic findings, particularly when it comes to Apple (AAPL 0.52%). While IDC thinks Apple's U.S. Mac shipments were roughly flat in the fourth quarter at negative 0.2%, Gartner believes the Mac maker posted a 5.4% increase during the fourth quarter.

Vendor

Q4 2012 U.S. Unit Shipments

Q4 2012 U.S. Market Share

Growth (YOY)

HP

4.7 million

26.6%

12.6%

Dell

3.4 million

19.2%

(16.5%)

Apple

2.1 million

12.3%

5.4%

Lenovo

1.5 million

8.4%

9.7%

Acer

1.4 million

7.9%

(21.6%)

Others

4.5 million

25.7%

(2%)

Total

17.5 million

100%

(2.1%)

Source: Gartner. Figures may not add up due to rounding. YOY = year over year.

The difference in domestic Mac estimates is a little more than 100,000 units in absolute terms, which isn't going to make or break the company's fourth-quarter results. Either way you slice it, though, Apple is continuing its streak of outperforming the broader PC market every quarter, a stat that Tim Cook likes to boast.

I've heard this one before
Naturally, the big culprit here continues to be tablet adoption as consumers shift media consumption to those devices in what Gartner refers to as a "structural shift." Instead of a reliable upgrade cycle, consumers are now likely to allow secondary PCs to become obsolete while shifting spending patterns to tablets.

The lines between different device categories continue to blend though, as Windows 8 takes on a plethora of shapes and sizes. Microsoft's whole goal with Windows 8 is to ambitiously offer a platform for all devices, and only time will tell if this is too much to ask.

Tablets continue to be predominantly consumption devices, but Gartner doesn't see that as a problem for their prospects. Some users will always need productivity machines, but an increasing proportion of consumers' casual tasks can be performed by tablets while shared PCs may be used to get some real work done.