Indeed, according to the study, PCs older than three years raise potential security and productivity issues. For example, the frequency of virus incidents rises 28 per cent for desktops and 58 per cent for notebooks when comparing PCs older than three years to those under. Downtime due to viruses also increased by 23 and 22 per cent, respectively.

Component failure rates also jumped dramatically, with hard drive failure rates rising from eight per cent to 33 per cent, and power supplies from 11 per cent to 49 per cent.

Additionally, Crooke noted that just as maintenance costs increase, PC warranties often expire at year three, putting increased cost on the business to maintain their older fleets. The bottom line, he said, is that when you consider the increased service costs and the lost productivity due to increased downtime experienced by older PCs, the capital cost of acquiring a new PC can be recovered within one year.

"Our view is a three-year refresh cycle is about the right refresh cycle, and it's borne out by this data," said Crooke. "The way SMBs do refresh varies drastically based on their IT sophistication. Some have a schedule and do it on a regular basis, and others do it when PCs fail which is a very disruptive way to do it. We'd encourage SMBs to get on a regular refresh cycle."

Tony Liao, associate vice-president, sales and marketing with hardware component manufacturer Gigabyte, said SMBs are challenged by security and maintenance costs but he expects them to come out of the downturn strong.