Today: The personal-computer market outperformed expectations in the holiday shopping season, two analysis firms report, with a strong boost from Hewlett-Packard and Apple. Also: SanDisk walloped on Wall Street as tech stocks drop.

THE LEAD: HP AND APPLE SAID TO BOOST PC SHIPMENTS IN HOLIDAY QUARTER

While the market for personal computers is suffering through uncertain times, two analyses predict that Hewlett-Packard and Apple managed to improve their sales of PC devices during the holiday season.

IDC and Gartner released their preliminary accounting of PC shipments during the holiday quarter Monday afternoon, and offered hopeful signs for the industry. IDC reported that shipments of PCs sank 2.8 percent year-over-year, better than its forecast of a 4.8 percent decline, while Gartner tracked a 1 percent increase overall.

The two groups track PCs differently, with Gartner including certain Microsoft machines that IDC counts as tablets, and IDC tracking Chromebooks, unlike Gartner. While IDC senior analyst Jay Chou spoke of “cautious optimism” sparked by the PC market’s fourth-quarter, Gartner was more effusive.

“The fourth quarter of 2014 was the best holiday for PC sales in recent history,” Gartner analyst Mikako Kitagawa pronounced in a news release.

While the reports differed on certain aspects of the larger market, they seemed to agree on one aspect: Silicon Valley’s two largest tech firms had a good holiday shopping season. Apple and Hewlett-Packard enjoyed double-digit percentage growth in shipments during the quarter in all aspects reported by the companies Monday.

HP, which lost its crown as the largest PC manufacturer in the world to Lenovo, moved closer to regaining its title in the final three months of 2014. Gartner reported that HP shipped nearly 15.77 million PCs in the fourth quarter, a 16 percent gain year-over-year and good for 18.8 percent of the overall market, just shy of Lenovo’s leading 19.4 percent share. IDC found similar growth at HP — a 15.1 percent year-over-year advance to 15.88 million units shipped — and a much closer race for largest market share, with HP receiving 19.7 percent and Lenovo 19.9 percent.

Shipments in the United States — where the Palo Alto company is still the market leader — jumped 26.2 percent from the holiday shopping season in 2013, according to both reports.

IDC’s report alternately described HP’s quarter in its announcement as “remarkable” and “tremendous,” while Gartner noted HP’s “strong growth.” IDC analyst Chou noted that HP’s lower priced offerings — namely Chromebooks and its Stream series of laptops — seemed popular as consumers aimed for the lower end of the PC market.

“They’ve gotten quite a bit of good traction with that, so it does look like HP is capitalizing on this still pretty fledgling consumer interest for PCs,” Chou said.

Apple, the only Silicon Valley tech company with larger annual revenues than HP, also showed a strong advances in PCs in the fourth quarter, according to both reports. IDC tabbed Apple as the fifth largest PC manufacturer worldwide thanks to sales of 5.75 million PCs in the fourth quarter, an increase of 18.9 percent from the 2013 holiday quarter.

“The markets that Apple serves are also the markets that are being more receptive to PCs right now,” Chou noted, with PC sales strongest in wealthier nations where consumers can afford the higher price point of Apple machines.

Gartner does not have Apple in its top five worldwide vendors — its accounting of Windows-based tablet/laptop hybrids gave Asus the No. 5 spot instead — so it does not break out worldwide shipments. However, Gartner did share shipments within the U.S., where Apple is No. 3 in market share, and found the Cupertino company’s shipments grew 11.5 percent to 2.12 million. IDC reported a stronger performance by Apple in the U.S. market, tracking growth of 18.1 percent to 2.25 million.

Both IDC and Gartner believe that people who bought tablets in the past few years are now replacing older PCs instead, and the end of Windows XP support by Microsoft in 2014 has helped boost the enterprise market for the devices. Analysts believe that those factors could be short term, leaving a mystery ahead for PC manufacturers.

“We would characterize this as a ‘less bad’ PC environment than some had been predicting,” FBR Capital Markets equity analyst Daniel Ives said in an email, adding, “That said, headwinds remain on this segment of the IT food chain heading into 2015.”

Hewlett-Packard stock fell 1.8 percent to $39.92 Monday, and bounced slightly in late trading after the reports were released, hitting $40. Apple dropped 2.5 percent to $109.25 as the company’s component suppliers enjoyed the fruits of strong iPhone sales.

SV150 MARKET REPORT: SANDISK DIVES ON TOUGH DAY FOR TECH STOCKS

Wall Street tumbled Monday as the price of oil continued to hit new lows, and Silicon Valley tech stocks sank farther than larger indexes as SanDisk was hit hard.

Flash-memory company SanDisk had its worst day on Wall Street since 2009, falling 13.9 percent to $83.57 after announcing that fourth-quarter revenues will come in lower than the Milpitas firm originally projected. In its announcement, SanDisk said that it sold fewer memory chips than it expected, both in the consumer sphere as well as to companies that put the flash cards in their mobile devices. The company predicted overall sales of $1.73 billion for the fourth quarter after previously saying it expected revenues of $1.8 billion to $1.85 billion; Bloomberg News reportedthat analysts on average expected SanDisk sales of $1.83 billion. SanDisk plans to announce final quarterly results on Jan. 21.

Earnings season kicks into high gear this week, with Synnex becoming the second SV150 company to announce results Monday. The Fremont company announced profits of $57.1 million, or $1.44 a share, on sales of $3.8 billion; shares jumped to about $75 in late trading, after closing with a 1.3 percent decline at $70.97. Linear Technology and Intel are also expected to announce fourth-quarter earnings this week, on Tuesday and Thursday respectively. Twitter fell 2 percent to $39.37 while facing a legal showdown with the United States government, and the San Francisco social-networking company is reportedly considering acquiring an Indian mobile company. Rival Facebook dropped 1.3 percent to $76.72 as Reuters reported the Menlo Park company attempted to invest in Chinese smartphone manufacturer Xiaomi. Tesla Motors declined 2.2 percent to $202.21 as General Motors announced a lower-priced electric Chevy at the Detroit Auto Show, where Tesla CEO Elon Musk is preparing to speak on Tuesday. Google angered Microsoft by exposing a hole in its security, and may anger users by reportedly cutting off updates for an older version of Android; the Mountain View Web giant fell 0.7 percent to $497.06. Netflix fell 3.2 percent to $318.83 after scoring wins at the Golden Globes, AMD held steady at $2.63 while the firm’s new CEO shook up the executive suite, and Symantec declined 0.3 percent to $25.29 whileacquiring talent and data from Boeing.

Up: Pandora, VMware, Palo Alto Networks, Workday, Cisco

Down: SanDisk, GoPro, Yelp, Netflix, Juniper, Apple, Applied Materials, Tesla, Twitter, Yahoo, HP, LinkedIn

The SV150 index of Silicon Valley’s largest tech companies: Down 21.72, or 1.3 percent, to 1,649.49

The tech-heavy Nasdaq composite index: Down 39.36, or 0.84 percent, to 4,664.71

The blue chip Dow Jones industrial average: Down 96.53, or 0.54 percent, to 17,640.84

And the widely watched Standard & Poor’s 500 index: Down 16.55, or 0.81 percent, to 2,028.26

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