Future Mac laptops may use Intel's 'Robson' technology
Accessing a disk drive is hundreds of times slower than accessing main system memory. Flash memory is slower than the DRAM used for system memory, but it's faster than pulling data from rotating magnetic media. One of the major sources of battery drain in a laptop is its spinning media. If you could get data from a large flash memory cache instead of spinning up the hard drive, you'd save a lot of power. Boot times would speed up substantially, too. Since a flash cache is nonvolatile, powering up from hibernate would be quicker and use less power than coming out of hibernation using the hard drive. Add the fact that hibernation uses less power than standby mode, and you can see the potential for big power savings.
So how does Robson work? Here's how it's explained by [url=http://www.extremetech.com/article2/0,1697,1936636,00.asp]ExtremeTech[/url]: "Intel proposes that the flash memory cache should be located on the motherboard. It's unclear whether it should be permanently installed or could be another type of memory socket. A Robson nonvolatile cache would require a driver to be loaded, however. The Robson cache connects to the I/O controller via PCI Express. Part of the technology is an intelligent prefetcher. The prefetcher anticipates which disk blocks will be needed from the hard drive and stores them in NV memory ahead of time. This data can persist even across boots. When requested by the operating system, the data is accessed using the low latency of solid state memory rather than the much higher-latency hard drive. For write commands, data is buffered in NV memory and later written to the hard disk to minimize unnecessary disk accesses. Cache configurations range from 128MB up to 4GB in size. And it's compatibleâ€”Robson works with any SATA drive across multiple operating systems."
Intel demoed is Robson cache technology in October 2005. It works with standard flash NAND chips anywhere from 64MB to 4GB in size.
As flash RAM capacities have skyrocketed, it has begun to replace hard drives in some applications. Most notable is the iPod nano, Apple's flash-based digital music player which comes in 2GB to 8GB capacities. After the nano's introduction, Apple phased out the iPod mini, which used one-inch hard drives for storage.
"Robson can not only speed up booting and open applications quicker, but conserve energy as well," said Nicole d'Onofrio, an analyst with technology research firm Current Analysis. "Intel will have an advantage in the mobile market."