By Jeremy Wagstaff, Chief Technology Correspondent, Asia SINGAPORE (Reuters) - Crammed with cells, memory chips have become about as small as they can physically get, and manufacturers are now experimenting with new technologies likely to shake up a $50 billion industry. Existing chips are expected to hit a physical limit within the next five years, triggering a race among chipmakers to find the technology to eventually supplant NAND flash and dynamic random access memory (DRAM), the two staples that have driven the computer world. 'Its opening up a whole new window of possibilities that for scientists is incredibly exciting and for business is incredibly frightening,' says Gary Bronner, vice president of Rambus Labs, a technology licensing company that specializes in memory. 'People dont like uncertainty and change.' That change wont happen overnight. Though some companies are already shipping products with new technologies, the quantities are small, and the early promise of some announcements often gives way to silence or scaled-back plans. And leading manufacturers are hedging their bets by investing in the new technologies alongside the old. 'Theres a lot of excitement about new technologies, but you need a dose of reality, too,' said Al Fazio, director of memory technology development at U.S. firm Intel Corp , which no longer manufactures memory but is a key player in the industry. For now, every device relies on RAM and either flash or traditional hard drives as it juggles data and applications between processor and storage. The price and performance of these technologies dictate which are used and in what quantity. For example, SanDisk Corp founder and then CEO Eli Harari was unable to meet Steve Jobs request in 2001 to provide flash memory for Apples first iPod because he couldnt compete on price with mini hard drives. Within four years, however, flash was cheap and small enough for Apple to design the tiny iPod Nano - and prices have fallen so much since that all phones, tablets and even lightweight laptops use flash. Its low price and increasing capacity have revolutionized the music, camera and film industries and helped make the smartphone the worlds most popular device. This demand has helped flash grow into a $21 billion industry last year, according to market researcher IHS iSuppli, double what it was worth in 2005. By 2016, revenues are expected to rise to $31 billion. And all these devices also use DRAM, an industry which was worth $30 billion last year. But within this success lies the problem. As manufacturers squeeze more memory into a smaller space they are close to the limits of what is physically possible with so few electrons to play with. Hence the experiments, by main manufacturers and smaller companies, with new technologies - ones that rely not on electrical charge to store data but on changing the structure of materials for data storage. At least in theory, this should make them more scalable.