Fourth quarter hard disk drive (HDD) shipments are set to be flat at best, according to the latest statistics from market watcher iSuppli.

The analyst has issued both optimistic and pessimistic forecasts for shipments in 2008.

Taking an optimistic approach, global HDD shipments could hit 157.5 million units, compared with the 158.3 million units in the previous third quarter. Based on this forecast, HDD shipments in 2008 will reach 593.2 million units, an increase of 14.9 per cent compared with the 516.2 million units shipped in 2007.

However, based on the pessimistic outlook, Q4 shipments could be as low as 149.4 million units, meaning the market will contract by 10 per cent, resulting in HDD shipments in 2008 of 585.1 million units, a 13.4 per cent increase on the past year.

Both predictions are lower than iSuppli’s original predictions for shipments in 2008 – which predicted a 16.6 per cent increase for the entire year.

Krishna Chander, senior analyst for storage systems at iSuppli, said: "We have reduced and rebalanced our 2009 forecast for PC unit shipments and are reducing out outlook for sales of HDD-equipped consumer electronics products.

"This is having a negative impact on HDD shipments, regardless of which scenario wins out. However, we are sticking with our optimistic outlook, given that the forecast fits in with recent predictions for leading manufacturers Seagate and Western Digital."

Despite the scenario, the growth expected in HDD shipments and revenue in 2009 is being fuelled by demand from the notebook PC and enterprise server segments. According to iSuppli, HDD demand from notebook PCs will rise at a double-digit pace during the next few quarters, HDDs for enterprise servers will see low, single-digit growth.

Chander added: "Although shipments seem to be robust in this uncertain economy, the revenue picture is more subdued. OEMs that traditionally purchase more components in the fourth quarter are reducing their procurement budgets, or are buying with low incoming inventory – resulting in reduced pricing for HDDs. "