IT spending declined $216 billion year-over-year in 2015 — and is expected to remain weak through 2019.

In 2016, Gartner predicts, IT spending will hit $3.5 trillion, only a 0.6 percent increase from 2015. Devices and telecoms will be hit the hardest, although hardware, IT services and software spending will also struggle.

Spending on data centers is the one silver lining, which we noted earlier this week. In 2015,  the ENE space grew on the back of network upgrades, which will continue this year. The server market also experienced stronger-than-expected demand from the big data storage sector.

Gartner looked at four areas of spending in its IT Spending Worldwide, fourth quarter 2015 update.

Data Center Systems: The Enterprise Network Equipment (ENE) and the server market will see grow 1 percent and 10.2 percent, respectively, year-over-year. Data center system spending will hit $75 billion this year, up 3 percent from 2015. 

Enterprise Software: The economic downturn in emerging markets has had little effect on the global enterprise software spending forecast. Gartner predicts that it will grow 5.3 percent on 2015 to $326 billion. 

Devices: The device market, which includes PCs, mobile phones, tablets and printers, will experience negative growth with end-user spend of $723 billion in 2015 falling to $719 billion in 2016. Premium devices are expected to drive the PC market with the move to Windows 10 and Intel Skylake-based PCs. That should create a 4 percent increase in spending on basic phones and a 1 percent decline in premium phones.

IT Services: Spending in the IT services market is expected to reach $940 billion, up 3.1 percent from 2015. This sector declined by 4.5 percent between 2014 and 2015. Growth is attributed to cloud infrastructure development and consumers' increased cloud adoption.