Seagate's latest Momentus notebook hard drives feature 256MB of flash memory and come in sizes of 80, 120 and 160GB. The point of the on-board NAND flash? To speed up performance by caching frequently used data in the NAND instead of reaching onto the hard drive every time. By storing boot information in there, it helps reduce Windows Vista startup time by 20%, and reduces power consumption by about 40%. And these figures will only rise in the future as BIOS and Vista device drivers improve. [Seagate via Digital Trends]
@Odomzig: Good question. The ideas behind this are applicable to any O.S. and there are standard ATA commands to manipulate the Non-Volatile cache, [www.t13.org] I hope Linux and Mac hackers are working on it.
Even without O.S. support, the drive could decide "You keep reading blocks X Y and Z, so I'll store them in NV cache" (drives already do this with their RAM cache) and "I'll keep your pending data writes in NV cache while waiting for the disk to spin up". Windows Vista's ReadyDrive takes specific advantage of it: "During shutdown or hibernate all the disk sectors needed to boot or resume are pinned into the NV cache... Offsets within files and/or specific LBAs can be specified by the PC OEM in registry for pinning in the NV Cache".