"More than half of new notebooks to use Flash drives by Q4 2009," shouts the headline on market watcher iSuppli's latest missive, before admitting soon after that, actually, it's counting not just solid-state drives but also regular HDDs with integrated Flash cache and separate caches like Intel's Turbo Memory module.

Still, it shows that non-volatile storage chips are going play an increasingly important part in laptop design going forward from the handful - if that - of machines available today with built-in Flash.

iSuppli reckons 143,600 notebooks and UMPCs were sent out by manufacturers in Q1. By Q4 2009, the figure will have increased to 24m devices - almost 60 per cent of the 40.1m mobile computers the researcher believes will be bought in that far-off quarter.

Driving it all are falling Flash prices, but 1GB of Flash chippery is still going to cost 14 times as much as 1GB of hard drive space in Q1 2009. That said, the price is disproportionately cheaper at the lower reaches of the Flash market: 8GB, say, will cost less than half the price of 16GB, and much less than a quarter of what 32GB will set you back.

If that rule's maintained, come 2009, 250GB of Flash storage may be cheap enough to be a serious alternative to hard drive capacities. By then, of course, laptop HDDs will be up to 500GB if not 1TB or more, but plenty of folk would be willing to put up with the lower capacity to gain the benefits - low power consumption, fast data-access times - of Flash.

The 32GB SSDs becoming increasingly common today aren't quite capacious enough to make that trade off worthwhile - big music and photo collections see to that - but a 250GB drive at the same price, two years down the line, might will be for most of us.

iSuppli sees it differently: it believes the majority of Flash-fitted laptops will contain hybrid hard drives rather than pure solid-state drives. Rotating storage will continue to spin for sometime yet.