Together with Windows Vista, Microsoft has introduced a new set of performance-enhancing features, called Windows ReadyDrive, which take advantage of hybrid hard disk technology to improve a computer's overall performance. Hybrid hard disks (H-HDD) incorporate a nonvolatile cache in a traditional mechanical HDD design. This cache (also called flash memory) ranges from 128MB to 1GB or more, and it's used by the SuperFetch feature of Windows Vista to store frequently accessed data, allowing for faster access speed. This also results in lower power consumption, as the mechanical part of the hard drive remains at rest while Windows Vista accesses only the cache area of the drive.
The majority of Hybrid hard drives will come in a 2.5-inch form factor with an ATA interface and capacity of up to 100GB. The first vendor to showcase Hybrid hard drives at WinHEC 2006 is Samsung, but the Hybrid hard drive market is expected to grow very fast; we should see hybrids replace traditional hard drives in all notebook computers relatively soon.
Also at WinHEC, Samsung introduced its first solid-state hard drives, where the entire hard drive is nonvolatile cache without any moving parts (almost like using a USB thumbdrive as the main hard drive for the notebook). This solution registers even better performance, reliability, and battery life than the hybrid hard drives, and it significantly reduces the boot time. However the price per gigabyte of a solid-state hard drive is currently about 30 times higher than that of a traditional hard drive, and capacity is limited to about 30GB only. For now, the H-HDD seems to be a better solution, offering the best of the both worlds: cheaper, faster, and bigger.