According to the market research company, worldwide PC shipments reached 68.1 million in Q4, a 3.7% decline year-on-year.
Mikako Kitagawa, senior principal analyst at Gartner, said: "The impact from the CPU shortage affected vendors' ability to fulfill demand created by business PC upgrades".
Kitagawa added that the second and third quarters of 2018 both showed growth relative to 2017, and it was the fourth quarter decline that pulled 2018's sales below 2017's. Gartner expects demand to improve in 2019 as CPUs become more available.
The Asia/Pacific PC market totaled 24.2 million units in the fourth quarter of 2018, a 4.6 percent decline from the same period of 2017.
Additionally, said Kitagawa, political and economic uncertainties in certain countries reduced the demand for PCs.
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Lenovo has recorded three consecutive quarters of double-digit year-over-year shipment growth, Gartner said. Region-wise, the US saw a small increase in volume from the past year, whereas it was all negative in the Europe Middle East, and Africa (EMEA) region and the Asia-Pacific region, excluding Japan, saw a single-digit decline - majorly due to the US-China trade war.
It's not the largest drop around, but it once again paints a rather lacklustre picture for the PC market, which past year actually looked like it was picking up a bit after quarters upon quarters of declining shipments.
Gartner had more detailed results about the U.S. market, where Microsoft remains the top 5 PC manufacturer behind HP, Dell, Lenovo and Apple. But a volatile stock market and a post-Black Friday/Cyber Monday downturn saw "the lowest sequential growth for a holiday quarter since the fourth quarter of 2012".
"The majority of the PC shipment decline in 2018 was due to weak consumer PC shipments". Lenovo's PC business recovered in the US. "Holiday sales are no longer a major factor driving consumer demand for PCs".
HP's PC market share declined 3.2 percent worldwide mostly due to a challenging quarter in the Americas. However, Asus took the fifth spot, surpassing Acer, with a share of 6.6 percent, marking a fall of 10.7 percent.